1# @ohos.thermal (Thermal Management) 2 3The **thermal** module provides thermal level-related callback and query APIs to obtain the information required for thermal control. 4 5> **NOTE** 6> 7> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8 9## Modules to Import 10 11```js 12import thermal from '@ohos.thermal'; 13``` 14 15## thermal.registerThermalLevelCallback<sup>9+</sup> 16 17registerThermalLevelCallback(callback: Callback<ThermalLevel>): void 18 19Subscribes to thermal level changes. 20 21**System capability:** SystemCapability.PowerManager.ThermalManager 22 23**Parameters** 24 25| Name | Type | Mandatory| Description | 26| -------- | ---------------------------- | ---- | ------------------------------ | 27| callback | Callback<ThermalLevel> | Yes | Callback used to return the result.| 28 29**Error codes** 30 31For details about the error codes, see [Thermal Manager Error Codes](../errorcodes/errorcode-thermal.md). 32 33| ID | Error Message | 34|---------|---------| 35| 4800101 | If connecting to the service failed. | 36 37**Example** 38 39```js 40try { 41 thermal.registerThermalLevelCallback(level => { 42 console.info('thermal level is: ' + level); 43 }); 44 console.info('register thermal level callback success.'); 45} catch(err) { 46 console.error('register thermal level callback failed, err: ' + err); 47} 48``` 49 50## thermal.unregisterThermalLevelCallback<sup>9+</sup> 51 52unregisterThermalLevelCallback(callback?: Callback\<void>): void 53 54Unsubscribes from thermal level changes. 55 56**System capability:** SystemCapability.PowerManager.ThermalManager 57 58**Parameters** 59 60| Name | Type | Mandatory| Description | 61| -------- | -------------------- | ---- | ---------------------------------------------- | 62| callback | Callback<void> | No | Callback that returns no value. If this parameter is not set, this API unsubscribes from all callbacks.| 63 64**Error codes** 65 66For details about the error codes, see [Thermal Manager Error Codes](../errorcodes/errorcode-thermal.md). 67 68| ID | Error Message | 69|---------|---------| 70| 4800101 | If connecting to the service failed. | 71 72**Example** 73 74```js 75try { 76 thermal.unregisterThermalLevelCallback(() => { 77 console.info('unsubscribe thermal level success.'); 78 }); 79 console.info('unregister thermal level callback success.'); 80} catch(err) { 81 console.error('unregister thermal level callback failed, err: ' + err); 82} 83``` 84 85## thermal.getLevel<sup>9+</sup> 86 87getLevel(): ThermalLevel 88 89Obtains the current thermal level. 90 91**System capability:** SystemCapability.PowerManager.ThermalManager 92 93**Return value** 94 95| Type | Description | 96| ------------ | ------------ | 97| ThermalLevel | Thermal level.| 98 99**Error codes** 100 101For details about the error codes, see [Thermal Manager Error Codes](../errorcodes/errorcode-thermal.md). 102 103| ID | Error Message | 104|---------|---------| 105| 4800101 | If connecting to the service failed. | 106 107**Example** 108 109```js 110try { 111 var level = thermal.getLevel(); 112 console.info('thermal level is: ' + level); 113} catch(err) { 114 console.error('get thermal level failed, err: ' + err); 115} 116``` 117 118## thermal.subscribeThermalLevel<sup>(deprecated)</sup> 119 120subscribeThermalLevel(callback: AsyncCallback<ThermalLevel>): void 121 122> **NOTE**<br>This API is deprecated since API version 9. You are advised to use [thermal.registerThermalLevelCallback](#thermalregisterthermallevelcallback9). 123 124Subscribes to thermal level changes. 125 126**System capability:** SystemCapability.PowerManager.ThermalManager 127 128**Parameters** 129 130| Name | Type | Mandatory| Description | 131| -------- | --------------------------------- | ---- | ------------------------------------------------------------ | 132| callback | AsyncCallback<ThermalLevel> | Yes | Callback used to return the result. The return value contains only one parameter, that is, thermal level. If an alarm is generated, you can use `// @ts-ignore` to suppress the alarm.| 133 134**Example** 135 136```js 137thermal.subscribeThermalLevel((level) => { 138 console.info('thermal level is: ' + level); 139}); 140``` 141 142## thermal.unsubscribeThermalLevel<sup>(deprecated)</sup> 143 144unsubscribeThermalLevel(callback?: AsyncCallback\<void>): void 145 146> **NOTE**<br>This API is deprecated since API version 9. You are advised to use [thermal.unregisterThermalLevelCallback](#thermalunregisterthermallevelcallback9). 147 148Unsubscribes from thermal level changes. 149 150**System capability:** SystemCapability.PowerManager.ThermalManager 151 152**Parameters** 153 154| Name | Type | Mandatory| Description | 155| -------- | ------------------------- | ---- | ---------------------------------------------- | 156| callback | AsyncCallback<void> | No | Callback that returns no value. If this parameter is not set, this API unsubscribes from all callbacks.| 157 158**Example** 159 160```js 161thermal.unsubscribeThermalLevel(() => { 162 console.info('unsubscribe thermal level success.'); 163}); 164``` 165 166## thermal.getThermalLevel<sup>(deprecated)</sup> 167 168getThermalLevel(): ThermalLevel 169 170> **NOTE**<br>This API is deprecated since API version 9. You are advised to use [thermal.getLevel](#thermalgetlevel9). 171 172Obtains the current thermal level. 173 174**System capability:** SystemCapability.PowerManager.ThermalManager 175 176**Return value** 177 178| Type | Description | 179| ------------ | ------ | 180| ThermalLevel | Thermal level obtained.| 181 182**Example** 183 184```js 185var level = thermal.getThermalLevel(); 186console.info('thermal level is: ' + level); 187``` 188 189## ThermalLevel 190 191Represents the thermal level. 192 193**System capability:** SystemCapability.PowerManager.ThermalManager 194 195| Name | Value | Description | 196| ---------- | ---- | ------------------------------------------------------------ | 197| COOL | 0 | The device is cool, and services are not restricted. | 198| NORMAL | 1 | The device is operational but is not cool. You need to pay attention to its heating.| 199| WARM | 2 | The device is warm. You need to stop or delay some imperceptible services.| 200| HOT | 3 | The device is heating up. You need to stop all imperceptible services and downgrade or reduce the load of other services.| 201| OVERHEATED | 4 | The device is overheated. You need to stop all imperceptible services and downgrade or reduce the load of major services.| 202| WARNING | 5 | The device is overheated and is about to enter the emergency state. You need to stop all imperceptible services and downgrade major services to the maximum extent.| 203| EMERGENCY | 6 | The device has entered the emergency state. You need to stop all services except those for the emergency help purposes.| 204