1# Unsubscribing from Common Events in C 2 3 4## When to Use 5 6After completing service requirements, subscribers need to unsubscribe from common events. 7 8## Available APIs 9 10For details about the APIs, see [CommonEvent](../../reference/apis-basic-services-kit/capi-common-event.md). 11 12| API | Description | 13| ------------------------------------ | ---------------------------------------------------------------- | 14|[CommonEvent_ErrCode OH_CommonEvent_UnSubscribe(const CommonEvent_Subscriber* subscriber)](../../reference/apis-basic-services-kit/capi-common-event.md#oh_commonevent_unsubscribe)|Creates the subscriber information.| 15 16## How to Develop 17 181. Reference header files. 19 20 ```c++ 21 #include <cstdint> 22 #include "hilog/log.h" 23 #include "BasicServicesKit/oh_commonevent.h" 24 ``` 25 262. Add dynamic link libraries to the CMake script. 27 28 ```txt 29 target_link_libraries(entry PUBLIC 30 libace_napi.z.so 31 libhilog_ndk.z.so 32 libohcommonevent.so 33 ) 34 ``` 35 36 373. Unsubscribe from a common event. 38 39 After a subscriber subscribes to a common event and meets service requirements, the subscriber can use [OH_CommonEvent_UnSubscribe](../../reference/apis-basic-services-kit/capi-common-event.md#oh_commonevent_unsubscribe) to unsubscribe from the event. 40 41 ```c++ 42 void Unsubscribe(CommonEvent_Subscriber* subscriber) { 43 // Unsubscribe from a common event by passing a subscriber. 44 int32_t ret = OH_CommonEvent_UnSubscribe(subscriber); 45 OH_LOG_Print(LOG_APP, LOG_INFO, 1, "CES_TEST", "OH_CommonEvent_UnSubscribe ret <%{public}d>.", ret); 46 } 47 ``` 48