# HID DDK ## Overview Provides HID driver development kit (DDK) functions, including those for creating a device, sending events to a device, and destroying a device. **System capability**: SystemCapability.Driver.HID.Extension **Since**: 11 ## Summary ### Files | Name| Description| | -------- | -------- | | [hid_ddk_api.h](hid__ddk__api_8h.md) | Declares the HID DDK functions for accessing an input device from the host.
File to include: <hid/hid_ddk_api.h>
Library: libhid.z.so| | [hid_ddk_types.h](hid__ddk__types_8h.md) | Defines the enum variables and structs used in the HID DDK.
File to include: <hid/hid_ddk_types.h>
Library: libhid.z.so| ### Structs | Name| Description| | -------- | -------- | | struct  [Hid_EmitItem](_hid___emit_item.md) | Defines event information.| | struct  [Hid_Device](_hid___device.md) | Defines basic device information.| | struct  [Hid_EventTypeArray](_hid___event_type_array.md) | Defines an array of event types.| | struct  [Hid_KeyCodeArray](_hid___key_code_array.md) | Defines an array of key codes.| | struct  [Hid_AbsAxesArray](_hid___abs_axes_array.md) | Defines an array of absolute coordinates.| | struct  [Hid_RelAxesArray](_hid___rel_axes_array.md) | Defines an array of relative coordinates.| | struct  [Hid_MscEventArray](_hid___msc_event_array.md) | Defines an array of miscellaneous events.| | struct  [Hid_EventProperties](_hid___event_properties.md) | Defines the event properties of a device.| | struct  [Hid_RawDevInfo](_hid___raw_dev_info.md) | Defines the raw device information.| ### Macros | Name| Description| | -------- | -------- | | [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size)   (16 \* 1024 - 1) | Defines the maximum size of the report buffer.| ### Types | Name| Description| | -------- | -------- | | typedef struct [Hid_EmitItem](_hid___emit_item.md) [Hid_EmitItem](#hid_emititem) | Defines event information.| | typedef struct [Hid_Device](_hid___device.md) [Hid_Device](#hid_device) | Defines basic device information.| | typedef struct [Hid_EventTypeArray](_hid___event_type_array.md) [Hid_EventTypeArray](#hid_eventtypearray) | Defines an array of event types.| | typedef struct [Hid_KeyCodeArray](_hid___key_code_array.md) [Hid_KeyCodeArray](#hid_keycodearray) | Defines an array of key codes.| | typedef struct [Hid_AbsAxesArray](_hid___abs_axes_array.md) [Hid_AbsAxesArray](#hid_absaxesarray) | Defines an array of absolute coordinates.| | typedef struct [Hid_RelAxesArray](_hid___rel_axes_array.md) [Hid_RelAxesArray](#hid_relaxesarray) | Defines an array of relative coordinates.| | typedef struct [Hid_MscEventArray](_hid___msc_event_array.md) [Hid_MscEventArray](#hid_msceventarray) | Defines an array of miscellaneous events.| | typedef struct [Hid_EventProperties](_hid___event_properties.md) [Hid_EventProperties](#hid_eventproperties) | Defines the event properties of a device.| | typedef struct [Hid_DeviceHandle](#hid_devicehandle) [Hid_DeviceHandle](#hid_devicehandle) | Defines the opaque USB HID device structure.| | typedef struct [Hid_RawDevInfo](_hid___raw_dev_info.md) [Hid_RawDevInfo](#hid_rawdevinfo) | Defines the raw device information.| ### Enums | Name| Description| | -------- | -------- | | [Hid_DeviceProp](#hid_deviceprop) {
HID_PROP_POINTER = 0x00, HID_PROP_DIRECT = 0x01, HID_PROP_BUTTON_PAD = 0x02, HID_PROP_SEMI_MT = 0x03, HID_PROP_TOP_BUTTON_PAD = 0x04, HID_PROP_POINTING_STICK = 0x05, HID_PROP_ACCELEROMETER = 0x06
} | Enumerates the properties of input devices.| | [Hid_EventType](#hid_eventtype) {
HID_EV_SYN = 0x00, HID_EV_KEY = 0x01, HID_EV_REL = 0x02, HID_EV_ABS = 0x03, HID_EV_MSC = 0x04
} | Enumerates the event types.| | [Hid_SynEvent](#hid_synevent) { HID_SYN_REPORT = 0, HID_SYN_CONFIG = 1, HID_SYN_MT_REPORT = 2, HID_SYN_DROPPED = 3 } | Enumerates sync events.| | [Hid_KeyCode](#hid_keycode) {
HID_KEY_A = 30, HID_KEY_B = 48, HID_KEY_C = 46, HID_KEY_D = 32, HID_KEY_E = 18, HID_KEY_F = 33, HID_KEY_G = 34, HID_KEY_H = 35, HID_KEY_I = 23, HID_KEY_J = 36, HID_KEY_K = 37, HID_KEY_L = 38, HID_KEY_M = 50, HID_KEY_N = 49, HID_KEY_O = 24, HID_KEY_P = 25, HID_KEY_Q = 16, HID_KEY_R = 19, HID_KEY_S = 31, HID_KEY_T = 20, HID_KEY_U = 22, HID_KEY_V = 47, HID_KEY_W = 17, HID_KEY_X = 45, HID_KEY_Y = 21, HID_KEY_Z = 44, HID_KEY_ESC = 1, HID_KEY_0 = 11, HID_KEY_1 = 2, HID_KEY_2 = 3, HID_KEY_3 = 4, HID_KEY_4 = 5, HID_KEY_5 = 6, HID_KEY_6 = 7, HID_KEY_7 = 8, HID_KEY_8 = 9, HID_KEY_9 = 10, HID_KEY_GRAVE = 41, HID_KEY_MINUS = 12, HID_KEY_EQUALS = 13, HID_KEY_BACKSPACE = 14, HID_KEY_LEFT_BRACKET = 26, HID_KEY_RIGHT_BRACKET = 27, HID_KEY_ENTER = 28, HID_KEY_LEFT_SHIFT = 42, HID_KEY_BACKSLASH = 43, HID_KEY_SEMICOLON = 39, HID_KEY_APOSTROPHE = 40, HID_KEY_SPACE = 57, HID_KEY_SLASH = 53, HID_KEY_COMMA = 51, HID_KEY_PERIOD = 52, HID_KEY_RIGHT_SHIFT = 54, HID_KEY_NUMPAD_0 = 82, HID_KEY_NUMPAD_1 = 79, HID_KEY_NUMPAD_2 = 80, HID_KEY_NUMPAD_3 = 81, HID_KEY_NUMPAD_4 = 75, HID_KEY_NUMPAD_5 = 76, HID_KEY_NUMPAD_6 = 77, HID_KEY_NUMPAD_7 = 71, HID_KEY_NUMPAD_8 = 72, HID_KEY_NUMPAD_9 = 73, HID_KEY_NUMPAD_DIVIDE = 70, HID_KEY_NUMPAD_MULTIPLY = 55, HID_KEY_NUMPAD_SUBTRACT = 74, HID_KEY_NUMPAD_ADD = 78, HID_KEY_NUMPAD_DOT = 83, HID_KEY_SYSRQ = 99, HID_KEY_DELETE = 111, HID_KEY_MUTE = 113, HID_KEY_VOLUME_DOWN = 114, HID_KEY_VOLUME_UP = 115, HID_KEY_BRIGHTNESS_DOWN = 224, HID_KEY_BRIGHTNESS_UP = 225, HID_BTN_0 = 0x100, HID_BTN_1 = 0x101, HID_BTN_2 = 0x102, HID_BTN_3 = 0x103, HID_BTN_4 = 0x104, HID_BTN_5 = 0x105, HID_BTN_6 = 0x106, HID_BTN_7 = 0x107, HID_BTN_8 = 0x108, HID_BTN_9 = 0x109, HID_BTN_LEFT = 0x110, HID_BTN_RIGHT = 0x111, HID_BTN_MIDDLE = 0x112, HID_BTN_SIDE = 0x113, HID_BTN_EXTRA = 0x114, HID_BTN_FORWARD = 0x115, HID_BTN_BACKWARD = 0x116, HID_BTN_TASK = 0x117, HID_BTN_TOOL_PEN = 0x140, HID_BTN_TOOL_RUBBER = 0x141, HID_BTN_TOOL_BRUSH = 0x142, HID_BTN_TOOL_PENCIL = 0x143, HID_BTN_TOOL_AIRBRUSH = 0x144, HID_BTN_TOOL_FINGER = 0x145, HID_BTN_TOOL_MOUSE = 0x146, HID_BTN_TOOL_LENS = 0x147, HID_BTN_TOOL_QUINT_TAP = 0x148, HID_BTN_STYLUS3 = 0x149, HID_BTN_TOUCH = 0x14a, HID_BTN_STYLUS = 0x14b, HID_BTN_STYLUS2 = 0x14c, HID_BTN_TOOL_DOUBLE_TAP = 0x14d, HID_BTN_TOOL_TRIPLE_TAP = 0x14e, HID_BTN_TOOL_QUAD_TAP = 0x14f, HID_BTN_WHEEL = 0x150
} | Enumerates the key codes.| | [Hid_AbsAxes](#hid_absaxes) {
HID_ABS_X = 0x00, HID_ABS_Y = 0x01, HID_ABS_Z = 0x02, HID_ABS_RX = 0x03, HID_ABS_RY = 0x04, HID_ABS_RZ = 0x05, HID_ABS_THROTTLE = 0x06, HID_ABS_RUDDER = 0x07, HID_ABS_WHEEL = 0x08, HID_ABS_GAS = 0x09, HID_ABS_BRAKE = 0x0a, HID_ABS_HAT0X = 0x10, HID_ABS_HAT0Y = 0x11, HID_ABS_HAT1X = 0x12, HID_ABS_HAT1Y = 0x13, HID_ABS_HAT2X = 0x14, HID_ABS_HAT2Y = 0x15, HID_ABS_HAT3X = 0x16, HID_ABS_HAT3Y = 0x17, HID_ABS_PRESSURE = 0x18, HID_ABS_DISTANCE = 0x19, HID_ABS_TILT_X = 0x1a, HID_ABS_TILT_Y = 0x1b, HID_ABS_TOOL_WIDTH = 0x1c, HID_ABS_VOLUME = 0x20, HID_ABS_MISC = 0x28
} | Enumerates the absolute coordinates.| | [Hid_RelAxes](#hid_relaxes) {
HID_REL_X = 0x00, HID_REL_Y = 0x01, HID_REL_Z = 0x02, HID_REL_RX = 0x03, HID_REL_RY = 0x04, HID_REL_RZ = 0x05, HID_REL_HWHEEL = 0x06, HID_REL_DIAL = 0x07, HID_REL_WHEEL = 0x08, HID_REL_MISC = 0x09, HID_REL_RESERVED = 0x0a, HID_REL_WHEEL_HI_RES = 0x0b, HID_REL_HWHEEL_HI_RES = 0x0c
} | Enumerates the relative coordinates.| | [Hid_MscEvent](#hid_mscevent) {
HID_MSC_SERIAL = 0x00, HID_MSC_PULSE_LED = 0x01, HID_MSC_GESTURE = 0x02, HID_MSC_RAW = 0x03, HID_MSC_SCAN = 0x04, HID_MSC_TIMESTAMP = 0x05
} | Enumerates miscellaneous input events.| | [Hid_DdkErrCode](#hid_ddkerrcode) {
HID_DDK_SUCCESS = 0, HID_DDK_NO_PERM = 201, HID_DDK_INVALID_PARAMETER = 401, HID_DDK_FAILURE = 27300001, HID_DDK_NULL_PTR = 27300002, HID_DDK_INVALID_OPERATION = 27300003, HID_DDK_TIMEOUT = 27300004, HID_DDK_INIT_ERROR = 27300005, HID_DDK_SERVICE_ERROR = 27300006, HID_DDK_MEMORY_ERROR = 27300007, HID_DDK_IO_ERROR = 27300008, HID_DDK_DEVICE_NOT_FOUND = 27300009
} | Enumerates the HID DDK error codes.| | [Hid_ReportType](#hid_reporttype) { HID_INPUT_REPORT = 0, HID_OUTPUT_REPORT = 1, HID_FEATURE_REPORT = 2 } | Defines the report (data packets exchanged between the HID device and the host) type.| ### Functions | Name| Description| | -------- | -------- | | int32_t [OH_Hid_CreateDevice](#oh_hid_createdevice) ([Hid_Device](_hid___device.md) \*hidDevice, [Hid_EventProperties](_hid___event_properties.md) \*hidEventProperties) | Creates a device.| | int32_t [OH_Hid_EmitEvent](#oh_hid_emitevent) (int32_t deviceId, const [Hid_EmitItem](_hid___emit_item.md) items[], uint16_t length) | Sends an event list to a device.| | int32_t [OH_Hid_DestroyDevice](#oh_hid_destroydevice) (int32_t deviceId) | Destroys a device.| | int32_t [OH_Hid_Init](#oh_hid_init) (void) | Initializes an HID DDK.| | int32_t [OH_Hid_Release](#oh_hid_release) (void) | Releases an HID DDK.| | int32_t [OH_Hid_Open](#oh_hid_open) (uint64_t deviceId, uint8_t interfaceIndex, [Hid_DeviceHandle](#hid_devicehandle) \*\*dev) | Opens the device specified by **deviceId** and **interfaceIndex**.| | int32_t [OH_Hid_Close](#oh_hid_close) ([Hid_DeviceHandle](#hid_devicehandle) \*\*dev) | Closes an HID device.| | int32_t [OH_Hid_Write](#oh_hid_write) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, uint8_t \*data, uint32_t length, uint32_t \*bytesWritten) | Writes reports to an HID device.| | int32_t [OH_Hid_ReadTimeout](#oh_hid_readtimeout) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, uint8_t \*data, uint32_t bufSize, int timeout, uint32_t \*bytesRead) | Reads reports from the HID device within the specified timeout interval.| | int32_t [OH_Hid_Read](#oh_hid_read) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, uint8_t \*data, uint32_t bufSize, uint32_t \*bytesRead) | Reads reports from the HID device. The blocking mode (that is, blocking remains active until data can be read) is used by default. You can call [OH_Hid_SetNonBlocking](#oh_hid_setnonblocking) to change the mode.| | int32_t [OH_Hid_SetNonBlocking](#oh_hid_setnonblocking) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, int nonBlock) | Sets the device read mode to non-blocking mode.| | int32_t [OH_Hid_GetRawInfo](#oh_hid_getrawinfo) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, [Hid_RawDevInfo](_hid___raw_dev_info.md) \*rawDevInfo) | Obtains the original device information.| | int32_t [OH_Hid_GetRawName](#oh_hid_getrawname) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, char \*data, uint32_t bufSize) | Obtains the original device name.| | int32_t [OH_Hid_GetPhysicalAddress](#oh_hid_getphysicaladdress) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, char \*data, uint32_t bufSize) | Obtains the physical address of the HID device.| | int32_t [OH_Hid_GetRawUniqueId](#oh_hid_getrawuniqueid) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, uint8_t \*data, uint32_t bufSize) | Obtains the original unique identifier of a device.| | int32_t [OH_Hid_SendReport](#oh_hid_sendreport) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, [Hid_ReportType](#hid_reporttype) reportType, const uint8_t \*data, uint32_t length) | Sends reports to the HID device.| | int32_t [OH_Hid_GetReport](#oh_hid_getreport) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, [Hid_ReportType](#hid_reporttype) reportType, uint8_t \*data, uint32_t bufSize) | Obtains reports from the HID device.| | int32_t [OH_Hid_GetReportDescriptor](#oh_hid_getreportdescriptor) ([Hid_DeviceHandle](#hid_devicehandle) \*dev, uint8_t \*buf, uint32_t bufSize, uint32_t \*bytesRead) | Obtains the report descriptor of the HID device.| ### Variables | Name| Description| | -------- | -------- | | uint16_t [Hid_EmitItem::type](#type) | Enumerates the event types.| | uint16_t [Hid_EmitItem::code](#code) | Event code.| | uint32_t [Hid_EmitItem::value](#value) | Event value.| | const char \* [Hid_Device::deviceName](#devicename) | Device name.| | uint16_t [Hid_Device::vendorId](#vendorid) | Vendor ID.| | uint16_t [Hid_Device::productId](#productid) | Product ID.| | uint16_t [Hid_Device::version](#version) | Version.| | uint16_t [Hid_Device::bustype](#bustype) | Bus type.| | [Hid_DeviceProp](#hid_deviceprop) \* [Hid_Device::properties](#properties) | Device properties.| | uint16_t [Hid_Device::propLength](#proplength) | Number of device properties.| | [Hid_EventType](#hid_eventtype) \* [Hid_EventTypeArray::hidEventType](#hideventtype) | Event type.| | uint16_t [Hid_EventTypeArray::length](#length-15) | Size of the array.| | [Hid_KeyCode](#hid_keycode) \* [Hid_KeyCodeArray::hidKeyCode](#hidkeycode) | Enumerates the key codes.| | uint16_t [Hid_KeyCodeArray::length](#length-25) | Size of the array.| | [Hid_AbsAxes](#hid_absaxes) \* [Hid_AbsAxesArray::hidAbsAxes](#hidabsaxes) | Array of absolute coordinates.| | uint16_t [Hid_AbsAxesArray::length](#length-35) | Size of the array.| | [Hid_RelAxes](#hid_relaxes) \* [Hid_RelAxesArray::hidRelAxes](#hidrelaxes) | Relative coordinate.| | uint16_t [Hid_RelAxesArray::length](#length-45) | Size of the array.| | [Hid_MscEvent](#hid_mscevent) \* [Hid_MscEventArray::hidMscEvent](#hidmscevent) | Miscellaneous event.| | uint16_t [Hid_MscEventArray::length](#length-55) | Size of the array.| | struct [Hid_EventTypeArray](_hid___event_type_array.md)[Hid_EventProperties::hidEventTypes](#hideventtypes) | Array of event types.| | struct [Hid_KeyCodeArray](_hid___key_code_array.md)[Hid_EventProperties::hidKeys](#hidkeys) | Array of key codes.| | struct [Hid_AbsAxesArray](_hid___abs_axes_array.md)[Hid_EventProperties::hidAbs](#hidabs) | Array of absolute coordinates.| | struct [Hid_RelAxesArray](_hid___rel_axes_array.md)[Hid_EventProperties::hidRelBits](#hidrelbits) | Array of relative coordinates.| | struct [Hid_MscEventArray](_hid___msc_event_array.md)[Hid_EventProperties::hidMiscellaneous](#hidmiscellaneous) | Array of miscellaneous events.| | int32_t [Hid_EventProperties::hidAbsMax](#hidabsmax) [64] | Maximum values of the absolute coordinates.| | int32_t [Hid_EventProperties::hidAbsMin](#hidabsmin) [64] | Minimum values of the absolute coordinates.| | int32_t [Hid_EventProperties::hidAbsFuzz](#hidabsfuzz) [64] | Fuzzy values of the absolute coordinates.| | int32_t [Hid_EventProperties::hidAbsFlat](#hidabsflat) [64] | Fixed values of the absolute coordinates.| | uint32_t [Hid_RawDevInfo::busType](#bustype) | Bus type.| | uint16_t [Hid_RawDevInfo::vendor](#vendor) | Provider ID.| | uint16_t [Hid_RawDevInfo::product](#product) | Product ID.| ## Macro Description ### HID_MAX_REPORT_BUFFER_SIZE ``` #define HID_MAX_REPORT_BUFFER_SIZE (16 * 1024 - 1) ``` **Description** Defines the maximum size of the report buffer. **Since**: 18 ## Type Description ### Hid_AbsAxesArray ``` typedef struct Hid_AbsAxesArray Hid_AbsAxesArray ``` **Description** Defines a struct for an array of absolute coordinates. **Since**: 11 ### Hid_Device ``` typedef struct Hid_Device Hid_Device ``` **Description** Defines a struct for basic device information. **Since**: 11 ### Hid_DeviceHandle ``` typedef struct Hid_DeviceHandle Hid_DeviceHandle ``` **Description** Defines the opaque USB HID device structure. **Since**: 18 ### Hid_EmitItem ``` typedef struct Hid_EmitItem Hid_EmitItem ``` **Description** Defines a struct for event information. **Since**: 11 ### Hid_EventProperties ``` typedef struct Hid_EventProperties Hid_EventProperties ``` **Description** Defines a struct for the event properties of a device. **Since**: 11 ### Hid_EventTypeArray ``` typedef struct Hid_EventTypeArray Hid_EventTypeArray ``` **Description** Defines a struct for an array of event types. **Since**: 11 ### Hid_KeyCodeArray ``` typedef struct Hid_KeyCodeArray Hid_KeyCodeArray ``` **Description** Defines a struct for an array of key codes. **Since**: 11 ### Hid_MscEventArray ``` typedef struct Hid_MscEventArray Hid_MscEventArray ``` **Description** Defines a struct for an array of miscellaneous events. **Since**: 11 ### Hid_RawDevInfo ``` typedef struct Hid_RawDevInfo Hid_RawDevInfo ``` **Description** Defines the raw device information. **Since**: 18 ### Hid_RelAxesArray ``` typedef struct Hid_RelAxesArray Hid_RelAxesArray ``` **Description** Defines a struct for an array of relative coordinates. **Since**: 11 ## Enum Description ### Hid_AbsAxes ``` enum Hid_AbsAxes ``` **Description** Enumerates the absolute coordinates. **Since**: 11 | Value| Description| | -------- | -------- | | HID_ABS_X | X axis.| | HID_ABS_Y | Y axis.| | HID_ABS_Z | Z axis.| | HID_ABS_RX | X axis of the right analog stick.| | HID_ABS_RY | Y axis of the right analog stick.| | HID_ABS_RZ | Z axis of the right analog stick.| | HID_ABS_THROTTLE | Throttle.| | HID_ABS_RUDDER | Rudder.| | HID_ABS_WHEEL | Scroll wheel.| | HID_ABS_GAS | Gas.| | HID_ABS_BRAKE | Brake.| | HID_ABS_HAT0X | HAT0X.| | HID_ABS_HAT0Y | HAT0Y.| | HID_ABS_HAT1X | HAT1X.| | HID_ABS_HAT1Y | HAT1Y.| | HID_ABS_HAT2X | HAT2X.| | HID_ABS_HAT2Y | HAT2Y.| | HID_ABS_HAT3X | HAT3X.| | HID_ABS_HAT3Y | HAT3Y.| | HID_ABS_PRESSURE | Pressure.| | HID_ABS_DISTANCE | Distance.| | HID_ABS_TILT_X | Tilt of X axis.| | HID_ABS_TILT_Y | Tilt of Y axis.| | HID_ABS_TOOL_WIDTH | Width of the touch tool.| | HID_ABS_VOLUME | Volume.| | HID_ABS_MISC | Others.| ### Hid_DdkErrCode ``` enum Hid_DdkErrCode ``` **Description** Enumerates the HID DDK error codes. **Since**: 11 | Value| Description| | -------- | -------- | | HID_DDK_SUCCESS | Operation succeeded.| | HID_DDK_NO_PERM | No permission. The value is changed from **-6** to **201** since API version 16.| | HID_DDK_INVALID_PARAMETER | Invalid parameter. The value is changed from **-2** to **401** since API version 16.| | HID_DDK_FAILURE | Operation failed. The value is changed from **-1** to **27300001** since API version 16.| | HID_DDK_NULL_PTR | Null pointer. The value is changed from **-4** to **27300002** since API version 16.| | HID_DDK_INVALID_OPERATION | Invalid operation. The value is changed from **-3** to **27300003** since API version 16.| | HID_DDK_TIMEOUT | Timeout. The value is changed from **-5** to **27300004** since API version 16.| | HID_DDK_INIT_ERROR | DDK initialization error. This enum is supported since API version 16.| | HID_DDK_SERVICE_ERROR | Service communication error. This enum is supported since API version 16.| | HID_DDK_MEMORY_ERROR | Memory-related errors, such as memory data copy failure and memory allocation failure. This enum is supported since API version 16.| | HID_DDK_IO_ERROR | I/O operation failure. This enum is supported since API version 16.| | HID_DDK_DEVICE_NOT_FOUND | Device not found. This enum is supported since API version 16.| ### Hid_DeviceProp ``` enum Hid_DeviceProp ``` **Description** Enumerates the properties of input devices. **Since**: 11 | Value| Description| | -------- | -------- | | HID_PROP_POINTER | Pointer device.| | HID_PROP_DIRECT | Direct input device.| | HID_PROP_BUTTON_PAD | Touch device with bottom keys.| | HID_PROP_SEMI_MT | Full multi-touch device.| | HID_PROP_TOP_BUTTON_PAD | Touch device with top soft keys.| | HID_PROP_POINTING_STICK | Pointing stick.| | HID_PROP_ACCELEROMETER | Accelerometer.| ### Hid_EventType ``` enum Hid_EventType ``` **Description** Enumerates the event types. **Since**: 11 | Value| Description| | -------- | -------- | | HID_EV_SYN | Sync event.| | HID_EV_KEY | Key event.| | HID_EV_REL | Relative coordinate event.| | HID_EV_ABS | Absolute coordinate event.| | HID_EV_MSC | Miscellaneous event.| ### Hid_KeyCode ``` enum Hid_KeyCode ``` **Description** Enumerates the key codes. **Since**: 11 | Value| Description| | -------- | -------- | | HID_KEY_A | Key A| | HID_KEY_B | Key B| | HID_KEY_C | Key C| | HID_KEY_D | Key D| | HID_KEY_E | Key E| | HID_KEY_F | Key F| | HID_KEY_G | Key G| | HID_KEY_H | Key H| | HID_KEY_I | Key I| | HID_KEY_J | Key J| | HID_KEY_K | Key K| | HID_KEY_L | Key L| | HID_KEY_M | Key M| | HID_KEY_N | Key N| | HID_KEY_O | Key O| | HID_KEY_P | Key P| | HID_KEY_Q | Key Q| | HID_KEY_R | Key R| | HID_KEY_S | Key S| | HID_KEY_T | Key T| | HID_KEY_U | Key U| | HID_KEY_V | Key V| | HID_KEY_W | Key W| | HID_KEY_X | Key X| | HID_KEY_Y | Key Y| | HID_KEY_Z | Key Z| | HID_KEY_ESC | Key Esc| | HID_KEY_0 | Key 0| | HID_KEY_1 | Key 1| | HID_KEY_2 | Key 2| | HID_KEY_3 | Key 3| | HID_KEY_4 | Key 4| | HID_KEY_5 | Key 5| | HID_KEY_6 | Key 6| | HID_KEY_7 | Key 7| | HID_KEY_8 | Key 8| | HID_KEY_9 | Key 9| | HID_KEY_GRAVE | Key `| | HID_KEY_MINUS | Key -| | HID_KEY_EQUALS | Key =| | HID_KEY_BACKSPACE | key Backspace| | HID_KEY_LEFT_BRACKET | Key [| | HID_KEY_RIGHT_BRACKET | Key ]| | HID_KEY_ENTER | Key Enter| | HID_KEY_LEFT_SHIFT | Left Shift| | HID_KEY_BACKSLASH | Key \| | HID_KEY_SEMICOLON | Key ;| | HID_KEY_APOSTROPHE | Key '| | HID_KEY_SPACE | Key Space| | HID_KEY_SLASH | Key /| | HID_KEY_COMMA | Key ,| | HID_KEY_PERIOD | Key .| | HID_KEY_RIGHT_SHIFT | Right Shift| | HID_KEY_NUMPAD_0 | Numeral 0 on the numeric keypad| | HID_KEY_NUMPAD_1 | Numeral 1 on the numeric keypad| | HID_KEY_NUMPAD_2 | Numeral 2 on the numeric keypad| | HID_KEY_NUMPAD_3 | Numeral 3 on the numeric keypad| | HID_KEY_NUMPAD_4 | Numeral 4 on the numeric keypad| | HID_KEY_NUMPAD_5 | Numeral 5 on the numeric keypad| | HID_KEY_NUMPAD_6 | Numeral 6 on the numeric keypad| | HID_KEY_NUMPAD_7 | Numeral 7 on the numeric keypad| | HID_KEY_NUMPAD_8 | Numeral 8 on the numeric keypad| | HID_KEY_NUMPAD_9 | Numeral 9 on the numeric keypad| | HID_KEY_NUMPAD_DIVIDE | Key / on the numeric keypad| | HID_KEY_NUMPAD_MULTIPLY | Key * on the numeric keypad| | HID_KEY_NUMPAD_SUBTRACT | Key - on the numeric keypad| | HID_KEY_NUMPAD_ADD | Key + on the numeric keypad| | HID_KEY_NUMPAD_DOT | Key . on the numeric keypad| | HID_KEY_SYSRQ | SYSRQ key| | HID_KEY_DELETE | Delete key| | HID_KEY_MUTE | Mute key| | HID_KEY_VOLUME_DOWN | Volume Down key| | HID_KEY_VOLUME_UP | Volume Down key| | HID_KEY_BRIGHTNESS_DOWN | Brightness Down key| | HID_KEY_BRIGHTNESS_UP | Brightness Up key| | HID_BTN_0 | Button 0| | HID_BTN_1 | Button 1| | HID_BTN_2 | Button 2| | HID_BTN_3 | Button 3| | HID_BTN_4 | Button 4| | HID_BTN_5 | Button 5| | HID_BTN_6 | Button 6| | HID_BTN_7 | Button 7| | HID_BTN_8 | Button 8| | HID_BTN_9 | Button 9| | HID_BTN_LEFT | Left mouse button| | HID_BTN_RIGHT | Right mouse button| | HID_BTN_MIDDLE | Middle mouse button| | HID_BTN_SIDE | Side mouse button| | HID_BTN_EXTRA | Extra mouse button| | HID_BTN_FORWARD | Mouse forward button| | HID_BTN_BACKWARD | Mouse backward button| | HID_BTN_TASK | Mouse task button| | HID_BTN_TOOL_PEN | Pen| | HID_BTN_TOOL_RUBBER | Rubber| | HID_BTN_TOOL_BRUSH | Brush| | HID_BTN_TOOL_PENCIL | Pencil| | HID_BTN_TOOL_AIRBRUSH | Air brush| | HID_BTN_TOOL_FINGER | Finger| | HID_BTN_TOOL_MOUSE | Mouse| | HID_BTN_TOOL_LENS | Lens| | HID_BTN_TOOL_QUINT_TAP | Five-finger touch| | HID_BTN_STYLUS3 | Stylus 3| | HID_BTN_TOUCH | Touch| | HID_BTN_STYLUS | Stylus| | HID_BTN_STYLUS2 | Stylus 2| | HID_BTN_TOOL_DOUBLE_TAP | Two-finger touch| | HID_BTN_TOOL_TRIPLE_TAP | Three-finger touch| | HID_BTN_TOOL_QUAD_TAP | Four-finger touch| | HID_BTN_WHEEL | Scroll wheel| ### Hid_MscEvent ``` enum Hid_MscEvent ``` **Description** Enumerates miscellaneous input events. **Since**: 11 | Value| Description| | -------- | -------- | | HID_MSC_SERIAL | Serial number| | HID_MSC_PULSE_LED | Pulse| | HID_MSC_GESTURE | Gesture| | HID_MSC_RAW | Start event| | HID_MSC_SCAN | Scan| | HID_MSC_TIMESTAMP | Timestamp| ### Hid_RelAxes ``` enum Hid_RelAxes ``` **Description** Enumerates the relative coordinates. **Since**: 11 | Value| Description| | -------- | -------- | | HID_REL_X | X axis.| | HID_REL_Y | Y axis.| | HID_REL_Z | Z axis| | HID_REL_RX | X axis of the right analog stick| | HID_REL_RY | Y axis of the right analog stick| | HID_REL_RZ | Z axis of the right analog stick| | HID_REL_HWHEEL | Horizontal scroll wheel| | HID_REL_DIAL | Scale| | HID_REL_WHEEL | Scroll wheel| | HID_REL_MISC | Others| | HID_REL_RESERVED | Reserved| | HID_REL_WHEEL_HI_RES | High-resolution scroll wheel| | HID_REL_HWHEEL_HI_RES | High-resolution horizontal scroll wheel| ### Hid_ReportType ``` enum Hid_ReportType ``` **Description** Defines the report (data packets exchanged between the HID device and the host) type. **Since**: 18 | Value| Description| | -------- | -------- | | HID_INPUT_REPORT | Input report.| | HID_OUTPUT_REPORT | Output report.| | HID_FEATURE_REPORT | Feature report.| ### Hid_SynEvent ``` enum Hid_SynEvent ``` **Description** Enumerates sync events. **Since**: 11 | Value| Description| | -------- | -------- | | HID_SYN_REPORT | End of an event.| | HID_SYN_CONFIG | Configuration synchronization.| | HID_SYN_MT_REPORT | End of a multi-touch ABS data packet.| | HID_SYN_DROPPED | Event discarded.| ## Function Description ### OH_Hid_Close() ``` int32_t OH_Hid_Close (Hid_DeviceHandle ** dev) ``` **Description** Closes an HID device. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_PARAMETER: Empty **dev**. ### OH_Hid_CreateDevice() ``` int32_t OH_Hid_CreateDevice (Hid_Device * hidDevice, Hid_EventProperties * hidEventProperties) ``` **Description** Creates a device. **Since**: 11 **Parameters** | Name| Description| | -------- | -------- | | hidDevice | Pointer to the basic information about the device to create, including the device name, vendor ID, and product ID.| | hidEventProperties | Pointer to the event properties related to the device to create, including the event type, key event properties, absolute coordinate event properties, and relative coordinate event properties.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - deviceID (a non-negative number) if the API call is successful. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_OPERATION: hid_ddk service connection failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. The input **hidDevice** is a null pointer. 2. The input **hidEventProperties** is a null pointer. 3. The length of **properties** exceeds 7 characters. 4. The length of **hidEventTypes** exceeds 5 characters. 5. The length of **hidKeys** exceeds 100 characters. 6. The length of **hidAbs** exceeds 26 characters. 7. The length of **hidRelBits** exceeds 13 characters. 8. The length of **hidMiscellaneous** exceeds 6 characters. - HID_DDK_FAILURE: Number of devices exceeding the maximum value (200). ### OH_Hid_DestroyDevice() ``` int32_t OH_Hid_DestroyDevice (int32_t deviceId) ``` **Description** Destroys a device. **Since**: 11 **Parameters** | Name| Description| | -------- | -------- | | deviceId | Device ID.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_OPERATION: Invalid operation. The hid_ddk service connection fails or the caller is not the device creator. - HID_DDK_FAILURE: Device not exist. ### OH_Hid_EmitEvent() ``` int32_t OH_Hid_EmitEvent (int32_t deviceId, const Hid_EmitItem items[], uint16_t length) ``` **Description** Sends an event list to a device. **Since**: 11 **Parameters** | Name| Description| | -------- | -------- | | deviceId | Device ID.| | items | List of the events to send. The event information includes the event type (**Hid_EventType**), code (**Hid_SynEvent**, **Hid_KeyCode**, **HidBtnCode**, **Hid_AbsAxes**, **Hid_RelAxes**, or **Hid_MscEvent**), and value (depending on the actual device input).| | length | Length of the event list (number of events to be sent at a time).| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_OPERATION: Invalid operation. The hid_ddk service connection fails or the caller is not the device creator. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. The device ID is smaller than 0. 2. The length of the input parameter exceeds 7 characters. 3. The input **items** is a null pointer. - HID_DDK_NULL_PTR: Null pointer. The input device is empty. - HID_DDK_FAILURE: Device not exist. ### OH_Hid_GetPhysicalAddress() ``` int32_t OH_Hid_GetPhysicalAddress (Hid_DeviceHandle * dev, char * data, uint32_t bufSize) ``` **Description** Obtains the physical address of the HID device. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | data | Buffer for storing the read data.| | bufSize | Size of the buffer for storing read data. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of **bufSize** is **0**. 4. The value of **bufSize** exceeds [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size). HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: Memory data copy error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_OPERATION: Invalid operation. ### OH_Hid_GetRawInfo() ``` int32_t OH_Hid_GetRawInfo (Hid_DeviceHandle * dev, Hid_RawDevInfo * rawDevInfo) ``` **Description** Obtains the original device information. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | rawDevInfo | Original device information, including the vendor ID, product ID, and bus type.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **rawDevInfo** is empty. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_OPERATION: Invalid operation. ### OH_Hid_GetRawName() ``` int32_t OH_Hid_GetRawName (Hid_DeviceHandle * dev, char * data, uint32_t bufSize) ``` **Description** Obtains the original device name. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | data | Buffer for storing the read data.| | bufSize | Size of the buffer for storing read data. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of **bufSize** is **0**. 4. The value of **bufSize** exceeds [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size). HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: Memory data copy error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_OPERATION: Invalid operation. ### OH_Hid_GetRawUniqueId() ``` int32_t OH_Hid_GetRawUniqueId (Hid_DeviceHandle * dev, uint8_t * data, uint32_t bufSize) ``` **Description** Obtains the original unique identifier of a device. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | data | Buffer for storing the read data.| | bufSize | Size of the buffer for storing read data. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of **bufSize** is **0**. 4. The value of **bufSize** exceeds [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size). HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: Memory data copy error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_OPERATION: Invalid operation. ### OH_Hid_GetReport() ``` int32_t OH_Hid_GetReport (Hid_DeviceHandle * dev, Hid_ReportType reportType, uint8_t * data, uint32_t bufSize) ``` **Description** Obtains reports from the HID device. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | reportType | Report type.| | data | Buffer for storing the read data.| | bufSize | Size of the buffer for storing read data. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of **bufSize** is **0**. 4. The value of **bufSize** exceeds [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size). - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: Memory data copy error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_OPERATION: Invalid operation. ### OH_Hid_GetReportDescriptor() ``` int32_t OH_Hid_GetReportDescriptor (Hid_DeviceHandle * dev, uint8_t * buf, uint32_t bufSize, uint32_t * bytesRead) ``` **Description** Obtains the report descriptor of the HID device. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | buf | Buffer for storing descriptors.| | bufSize | Size of the buffer, in bytes. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| | bytesRead | Number of bytes to read.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **buf** is empty. 3. The value of **bufSize** is **0**. 4. The value of **bufSize** exceeds that of **[HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size)**. 5. **bytesRead** is empty. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: Memory data copy error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_OPERATION: Invalid operation. ### OH_Hid_Init() ``` int32_t OH_Hid_Init (void) ``` **Description** Initializes an HID DDK. **Since**: 18 **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INIT_ERROR: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. ### OH_Hid_Open() ``` int32_t OH_Hid_Open (uint64_t deviceId, uint8_t interfaceIndex, Hid_DeviceHandle ** dev) ``` **Description** Opens the device specified by **deviceId** and **interfaceIndex**. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | deviceId | Device ID.| | interfaceIndex | Interface index for the API of the HID device.| | dev | Device operation handle.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: dev memory application error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_PARAMETER: Empty **dev**. - HID_DDK_DEVICE_NOT_FOUND: Device not found based on the specified **deviceId** and **interfaceIndex**. ### OH_Hid_Read() ``` int32_t OH_Hid_Read (Hid_DeviceHandle * dev, uint8_t * data, uint32_t bufSize, uint32_t * bytesRead) ``` **Description** Reads reports from the HID device. The blocking mode (that is, blocking remains active until data can be read) is used by default. You can call [OH_Hid_SetNonBlocking](#oh_hid_setnonblocking) to change the mode. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | data | Buffer for storing the read data.| | bufSize | Size of the buffer for storing read data. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| | bytesRead | Number of bytes to read.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of **bufSize** is **0**. 4. The value of **bufSize** exceeds that of **[HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size)**. 5. **bytesRead** is empty. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: Memory data copy error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_TIMEOUT: Reading timed out. ### OH_Hid_ReadTimeout() ``` int32_t OH_Hid_ReadTimeout (Hid_DeviceHandle * dev, uint8_t * data, uint32_t bufSize, int timeout, uint32_t * bytesRead) ``` **Description** Reads reports from the HID device within the specified timeout interval. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | data | Buffer for storing the read data.| | bufSize | Size of the buffer for storing read data. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| | timeout | Timeout interval, in ms. The value **-1** indicates block waiting.| | bytesRead | Number of bytes to read.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of **bufSize** is **0**. 4. The value of **bufSize** exceeds that of **[HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size)**. 5. **bytesRead** is empty. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_MEMORY_ERROR: Memory data copy error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_TIMEOUT: Reading timed out. ### OH_Hid_Release() ``` int32_t OH_Hid_Release (void) ``` **Description** Releases an HID DDK. **Since**: 18 **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. ### OH_Hid_SendReport() ``` int32_t OH_Hid_SendReport (Hid_DeviceHandle * dev, Hid_ReportType reportType, const uint8_t * data, uint32_t length) ``` **Description** Sends reports to the HID device. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | reportType | Report type.| | data | Data to be sent.| | length | Length of the data to be sent, in bytes. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of **length** is **0**; 4. The value of **length** exceeds [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size). - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_IO_ERROR: I/O operation error. - HID_DDK_INVALID_OPERATION: Invalid operation. ### OH_Hid_SetNonBlocking() ``` int32_t OH_Hid_SetNonBlocking (Hid_DeviceHandle * dev, int nonBlock) ``` **Description** Sets the device read mode to non-blocking mode. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | nonBlock | Whether to enable the non-blocking mode for reading data.
- 1: The non-blocking mode is enabled. When [OH_Hid_Read](#oh_hid_read) is called, if the device has readable data, **HID_DDK_SUCCESS** is returned; if the device has no readable data, **HID_DDK_TIMEOUT** is returned.
- 0: The non-blocking mode is disabled.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. The value of **nonBlock** is not **1** or **0**. - HID_DDK_SERVICE_ERROR: DDK service communication error. ### OH_Hid_Write() ``` int32_t OH_Hid_Write (Hid_DeviceHandle * dev, uint8_t * data, uint32_t length, uint32_t * bytesWritten) ``` **Description** Writes reports to an HID device. **Since**: 18 **Parameters** | Name| Description| | -------- | -------- | | dev | Device operation handle.| | data | Data to be written.| | length | Length of the data to be written, in bytes. The value cannot exceed [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size).| | bytesWritten | Number of written bytes.| **Required Permissions** ohos.permission.ACCESS_DDK_HID **Returns** - HID_DDK_SUCCESS: Operation succeeded. - HID_DDK_NO_PERM: Permission verification failed. - HID_DDK_INVALID_PARAMETER: Parameter verification failed. Possible causes: 1. **dev** is empty. 2. **data** is empty. 3. The value of length is **0**; 4. The value of **length** exceeds [HID_MAX_REPORT_BUFFER_SIZE](#hid_max_report_buffer_size); 5. **bytesWritten** is empty. - HID_DDK_INIT_ERROR DDK: DDK initialization error. - HID_DDK_SERVICE_ERROR: DDK service communication error. - HID_DDK_IO_ERROR: I/O operation error. ## Variable Description ### bustype ``` uint16_t Hid_Device::bustype ``` **Description** Bus type. ### busType ``` uint32_t Hid_RawDevInfo::busType ``` **Description** Bus type. ### code ``` uint16_t Hid_EmitItem::code ``` **Description** Event code. ### deviceName ``` const char* Hid_Device::deviceName ``` **Description** Device name. ### hidAbs ``` struct Hid_AbsAxesArray Hid_EventProperties::hidAbs ``` **Description** Array of absolute coordinates. ### hidAbsAxes ``` Hid_AbsAxes* Hid_AbsAxesArray::hidAbsAxes ``` **Description** Array of absolute coordinates. ### hidAbsFlat ``` int32_t Hid_EventProperties::hidAbsFlat[64] ``` **Description** Fixed values of the absolute coordinates. ### hidAbsFuzz ``` int32_t Hid_EventProperties::hidAbsFuzz[64] ``` **Description** Fuzzy values of the absolute coordinates. ### hidAbsMax ``` int32_t Hid_EventProperties::hidAbsMax[64] ``` **Description** Maximum values of the absolute coordinates. ### hidAbsMin ``` int32_t Hid_EventProperties::hidAbsMin[64] ``` **Description** Minimum values of the absolute coordinates. ### hidEventType ``` Hid_EventType* Hid_EventTypeArray::hidEventType ``` **Description** Event type. ### hidEventTypes ``` struct Hid_EventTypeArray Hid_EventProperties::hidEventTypes ``` **Description** Array of event types. ### hidKeyCode ``` Hid_KeyCode* Hid_KeyCodeArray::hidKeyCode ``` **Description** Enumerates the key codes. ### hidKeys ``` struct Hid_KeyCodeArray Hid_EventProperties::hidKeys ``` **Description** Array of key codes. ### hidMiscellaneous ``` struct Hid_MscEventArray Hid_EventProperties::hidMiscellaneous ``` **Description** Array of miscellaneous events. ### hidMscEvent ``` Hid_MscEvent* Hid_MscEventArray::hidMscEvent ``` **Description** Miscellaneous event. ### hidRelAxes ``` Hid_RelAxes* Hid_RelAxesArray::hidRelAxes ``` **Description** Relative coordinate. ### hidRelBits ``` struct Hid_RelAxesArray Hid_EventProperties::hidRelBits ``` **Description** Array of relative coordinates. ### length [1/5] ``` uint16_t Hid_EventTypeArray::length ``` **Description** Size of the array. ### length [2/5] ``` uint16_t Hid_KeyCodeArray::length ``` **Description** Size of the array. ### length [3/5] ``` uint16_t Hid_AbsAxesArray::length ``` **Description** Size of the array. ### length [4/5] ``` uint16_t Hid_RelAxesArray::length ``` **Description** Size of the array. ### length [5/5] ``` uint16_t Hid_MscEventArray::length ``` **Description** Size of the array. ### product ``` uint16_t Hid_RawDevInfo::product ``` **Description** Product ID. ### productId ``` uint16_t Hid_Device::productId ``` **Description** Product ID. ### properties ``` Hid_DeviceProp* Hid_Device::properties ``` **Description** Device properties. ### propLength ``` uint16_t Hid_Device::propLength ``` **Description** Number of device properties. ### type ``` uint16_t Hid_EmitItem::type ``` **Description** Enumerates the event types. ### value ``` uint32_t Hid_EmitItem::value ``` **Description** Event value. ### vendor ``` uint16_t Hid_RawDevInfo::vendor ``` **Description** Provider ID. ### vendorId ``` uint16_t Hid_Device::vendorId ``` **Description** Vendor ID. ### version ``` uint16_t Hid_Device::version ``` **Description** Version.