# 获取设备的位置信息开发指导(C/C++) ## 场景介绍 开发者可以调用HarmonyOS位置相关接口，监听设备的位置变化。 ## 函数说明 |名称|描述| |:---------------------------------------------------------------------------------------------------------------------------------------------|:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| |OH_Location_IsLocatingEnabled(bool* enabled)|查询位置开关是否开启。| |OH_Location_StartLocating(const Location_RequestConfig* requestConfig)|启动定位并订阅位置变化。| |Location_ResultCode OH_Location_StopLocating(const Location_RequestConfig* requestConfig)|停止定位并取消订阅位置变化。| |OH_LocationInfo_GetBasicInfo(Location_Info* location)|从定位结果中获取基本信息，如经纬度、海拔、速度等信息。| |OH_LocationInfo_GetAdditionalInfo(Location_Info* location, char* additionalInfo, uint32_t length)|从定位结果中获取附加信息。附加信息是一个JSON格式的字符串。| |OH_Location_CreateRequestConfig(void)|创建一个位置请求参数结构体实例。| |OH_Location_DestroyRequestConfig(Location_RequestConfig* requestConfig)|销毁位置请求参数实例并回收内存。| |OH_LocationRequestConfig_SetUseScene(Location_RequestConfig* requestConfig, Location_UseScene useScene)|设置发起定位时的用户活动场景。 如果设置了useScene，则powerConsumptionScene无效。 如果未设置useScene，且设置了powerConsumptionScene，则该参数生效。 如果两个参数都不设置，则默认useScene为LOCATION_USE_SCENE_DAILY_LIFE_SERVICE,powerConsumptionScene参数无效。| |OH_LocationRequestConfig_SetPowerConsumptionScene(Location_RequestConfig* requestConfig, Location_PowerConsumptionScene powerConsumptionScene)|设置发起定位时的功耗场景。| |OH_LocationRequestConfig_SetInterval(Location_RequestConfig* requestConfig, int interval)|设置定位结果上报时间间隔。| |OH_LocationRequestConfig_SetCallback(Location_RequestConfig* requestConfig, Location_InfoCallback callback, void* userData)|设置用于接收位置上报的回调函数。| ## 开发步骤 1. 新建一个Native C++工程。 ![](https://contentcenter-vali-drcn.dbankcdn.cn/pvt_2/DeveloperAlliance_scene_100_1/f2/v3/idm6EbZVTdanVKPe6l7YQg/zh-cn_image_0000002784663753.png?HW-CC-KV=V1&HW-CC-Date=20261009T092711Z&HW-CC-Expire=31536000000&HW-CC-Sign=B01FE711FA3747C35C66DD0DE9001A112BABD18BB520064136342A5077571A16) 2. 获取设备的位置信息，需要有位置权限，位置权限申请的方法和步骤见[申请位置权限开发指导](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/location-permission-guidelines)。 3. CMakeLists.txt文件中引入动态依赖库。 ```c target_link_libraries(entry PUBLIC libace_napi.z.so) target_link_libraries(entry PUBLIC libhilog_ndk.z.so) target_link_libraries(entry PUBLIC liblocation_ndk.so) ``` 4. 在napi_init.cpp文件中编码，首先导入模块。 ```c #include "napi/native_api.h" #include "LocationKit/oh_location.h" #include "LocationKit/oh_location_type.h" #include "hilog/log.h" #include ``` 5. 调用获取位置接口之前需要先判断位置开关是否打开。 查询当前位置开关状态，返回结果为布尔值，true代表位置开关开启，false代表位置开关关闭，示例代码如下： ```c static napi_value OhLocationIsEnabled(napi_env env, napi_callback_info info) { bool isEnabled = false; int resultCode = OH_Location_IsLocatingEnabled(&isEnabled); napi_value result = NULL; napi_get_boolean(env, isEnabled, &result); return result; } // 在Init函数中补充接口。 EXTERN_C_START static napi_value Init(napi_env env, napi_value exports) { napi_property_descriptor desc[] = { {"ohLocationIsEnabled", NULL, OhLocationIsEnabled, NULL, NULL, NULL, napi_default, NULL}, }; napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc); return exports; } EXTERN_C_END ``` 6. 定位位置变化。 ```c // 定义一个请求参数 struct Location_RequestConfig *g_requestConfig = NULL; void *mydata = NULL; // 定义一个回调函数用来接收位置信息 void reportLocation(Location_Info* location, void* userData) { Location_BasicInfo baseInfo = OH_LocationInfo_GetBasicInfo(location); char additionalInfo[1024] = ""; Location_ResultCode result = OH_LocationInfo_GetAdditionalInfo(location, additionalInfo, sizeof(additionalInfo)); if (mydata == userData) { OH_LOG_INFO(LOG_APP, "userData is mydata"); } return; } // 订阅位置信息 static napi_value OhLocationStartLocating(napi_env env, napi_callback_info info) { if (g_requestConfig == NULL) { g_requestConfig = OH_Location_CreateRequestConfig(); } OH_LocationRequestConfig_SetUseScene(g_requestConfig, LOCATION_USE_SCENE_NAVIGATION); OH_LocationRequestConfig_SetInterval(g_requestConfig, 1); mydata = (void *)malloc(sizeof("mydata")); // 用户自定义任意类型，callback 透传返回 OH_LocationRequestConfig_SetCallback(g_requestConfig, reportLocation, mydata); OH_Location_StartLocating(g_requestConfig); int32_t ret = 0; napi_value result = NULL; napi_create_int32(env, ret, &result); return result; } // 取消订阅位置信息， g_requestConfig要和订阅时传入的对象保持一致 static napi_value OhLocationStopLocating(napi_env env, napi_callback_info info) { OH_Location_StopLocating(g_requestConfig); if (g_requestConfig != NULL) { OH_Location_DestroyRequestConfig(g_requestConfig); g_requestConfig = NULL; } free(mydata); mydata = NULL; int32_t ret = 0; napi_value result = NULL; napi_create_int32(env, ret, &result); return result; } // 在Init函数中补充接口。 EXTERN_C_START static napi_value Init(napi_env env, napi_value exports) { napi_property_descriptor desc[] = { {"ohLocationStartLocating", NULL, OhLocationStartLocating, NULL, NULL, NULL, napi_default, NULL}, {"ohLocationStopLocating", NULL, OhLocationStopLocating, NULL, NULL, NULL, napi_default, NULL}, }; napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc); return exports; } EXTERN_C_END ``` 7. 在types/libentry路径下index.d.ts文件中引入Napi接口。 ```c export const ohLocationIsEnabled: () => boolean; export const ohLocationStartLocating: () => number; export const ohLocationStopLocating: () => number; ``` 8. 删除Index.ets中的已废弃函数。 ```js .onClick(() => { hilog.info(0x0000, 'testTag', 'Test NAPI 2 + 3 = %{public}d', testNapi.add(2, 3)); }) ```