# 事件拦截开发指导（C/C++） ## 功能介绍 从API version 12开始，多模为应用提供了创建和删除按键、输入事件（鼠标、触摸和轴事件）拦截的能力。使用场景例如：云桌面应用需要拦截按键、鼠标、触摸和轴事件。 ## 接口说明 创建和删除事件拦截相关接口如下表所示，接口详细介绍请参考[oh_input_manager.h](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/capi-oh-input-manager-h)。 |接口名称|描述| |:-------------------------------------------------------------------------------------------------------------------------|:--------------------| |Input_Result OH_Input_AddKeyEventInterceptor(Input_KeyEventCallback callback, Input_InterceptorOptions *option)|添加按键事件的拦截。| |Input_Result OH_Input_AddInputEventInterceptor(Input_InterceptorEventCallback *callback, Input_InterceptorOptions *option)|添加输入事件拦截，包括鼠标、触屏和轴事件。| |Input_Result OH_Input_RemoveKeyEventInterceptor(void)|移除按键事件拦截。| |Input_Result OH_Input_RemoveInputEventInterceptor(void)|移除输入事件拦截，包括鼠标、触屏和轴事件。| ## 开发步骤 ### 链接动态库 调用创建和删除事件拦截前，需链接相关动态库。链接动态库的方法是，在CMakeLists.txt文件中做下面例子所示的配置： ```txt target_link_libraries(entry PUBLIC libohinput.so) ``` ### 申请所需权限 应用需要在module.json5中添加下面权限的配置，详细的配置方法参考[声明权限文档](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/declare-permissions)。 ```json "requestPermissions": [ { "name": "ohos.permission.INTERCEPT_INPUT_EVENT" } ] ``` ### 创建事件拦截 * **按键事件** struct KeyEvent { int32_t action; int32_t keyCode; int64_t actionTime { -1 }; }; // 定义按键事件回调函数 void OnKeyEventCallback(const Input_KeyEvent* keyEvent) { KeyEvent event; // Input_KeyEvent的生命周期仅限于回调函数内，回调函数执行完毕后会被自动销毁 event.action = OH_Input_GetKeyEventAction(keyEvent); event.keyCode = OH_Input_GetKeyEventKeyCode(keyEvent); event.actionTime = OH_Input_GetKeyEventActionTime(keyEvent); // ... } static napi_value AddKeyEventInterceptor(napi_env env, napi_callback_info info) { Input_Result ret = OH_Input_AddKeyEventInterceptor(OnKeyEventCallback, nullptr); // ... } static napi_value RemoveKeyEventInterceptor(napi_env env, napi_callback_info info) { Input_Result ret = OH_Input_RemoveKeyEventInterceptor(); // ... } * **输入拦截（鼠标、触摸和轴事件）** struct MouseEvent { int32_t action; int32_t displayX; int32_t displayY; int32_t button { -1 }; int32_t axisType { -1 }; float axisValue { 0.0f }; int64_t actionTime { -1 }; }; struct TouchEvent { int32_t action; int32_t id; int32_t displayX; int32_t displayY; int64_t actionTime { -1 }; }; struct AxisEvent { int32_t axisAction; float displayX; float displayY; std::map axisValues; int64_t actionTime { -1 }; int32_t sourceType; int32_t axisEventType { -1 }; }; // 定义鼠标事件回调函数 void OnMouseEventCallback(const Input_MouseEvent* mouseEvent) { MouseEvent event; // Input_MouseEvent的生命周期仅在回调函数内，回调函数结束时被销毁 event.action = OH_Input_GetMouseEventAction(mouseEvent); event.displayX = OH_Input_GetMouseEventDisplayX(mouseEvent); event.displayY = OH_Input_GetMouseEventDisplayY(mouseEvent); event.button = OH_Input_GetMouseEventButton(mouseEvent); event.axisType = OH_Input_GetMouseEventAxisType(mouseEvent); event.axisValue = OH_Input_GetMouseEventAxisValue(mouseEvent); event.actionTime = OH_Input_GetMouseEventActionTime(mouseEvent); // ... } // 定义触摸事件回调函数 void OnTouchEventCallback(const Input_TouchEvent* touchEvent) { TouchEvent event; // Input_TouchEvent的生命周期仅在回调函数内，回调函数结束时被销毁 event.action = OH_Input_GetTouchEventAction(touchEvent); event.id = OH_Input_GetTouchEventFingerId(touchEvent); event.displayX = OH_Input_GetTouchEventDisplayX(touchEvent); event.displayY = OH_Input_GetTouchEventDisplayY(touchEvent); event.actionTime = OH_Input_GetTouchEventActionTime(touchEvent); // ... } // 定义轴事件回调函数 void OnAxisEventCallback(const Input_AxisEvent* axisEvent) { AxisEvent event; // Input_AxisEvent的生命周期仅在回调函数内，回调函数结束时被销毁 InputEvent_AxisAction action; Input_Result ret = OH_Input_GetAxisEventAction(axisEvent, &action); event.axisAction = action; ret = OH_Input_GetAxisEventDisplayX(axisEvent, &event.displayX); ret = OH_Input_GetAxisEventDisplayY(axisEvent, &event.displayY); ret = OH_Input_GetAxisEventActionTime(axisEvent, &event.actionTime); InputEvent_SourceType sourceType; ret = OH_Input_GetAxisEventSourceType(axisEvent, &sourceType); event.sourceType = sourceType; InputEvent_AxisEventType axisEventType; ret = OH_Input_GetAxisEventType(axisEvent, &axisEventType); event.axisEventType = axisEventType; if (event.axisEventType == AXIS_EVENT_TYPE_PINCH) { double value = 0; ret = OH_Input_GetAxisEventAxisValue(axisEvent, AXIS_TYPE_PINCH, &value); event.axisValues.insert(std::make_pair(AXIS_TYPE_PINCH, value)); ret = OH_Input_GetAxisEventAxisValue(axisEvent, AXIS_TYPE_ROTATE, &value); event.axisValues.insert(std::make_pair(AXIS_TYPE_ROTATE, value)); } else if (event.axisEventType == AXIS_EVENT_TYPE_SCROLL) { double value = 0; ret = OH_Input_GetAxisEventAxisValue(axisEvent, AXIS_TYPE_SCROLL_VERTICAL, &value); event.axisValues.insert(std::make_pair(AXIS_TYPE_SCROLL_VERTICAL, value)); ret = OH_Input_GetAxisEventAxisValue(axisEvent, AXIS_TYPE_SCROLL_HORIZONTAL, &value); event.axisValues.insert(std::make_pair(AXIS_TYPE_SCROLL_HORIZONTAL, value)); } // ... } // 输入事件回调函数结构体 Input_InterceptorEventCallback g_eventCallback; static napi_value AddEventInterceptor(napi_env env, napi_callback_info info) { // 设置鼠标事件回调函数 g_eventCallback.mouseCallback = OnMouseEventCallback; // 设置触摸事件回调函数 g_eventCallback.touchCallback = OnTouchEventCallback; // 设置轴事件回调函数 g_eventCallback.axisCallback = OnAxisEventCallback; Input_Result ret = OH_Input_AddInputEventInterceptor(&g_eventCallback, nullptr); // ... } static napi_value RemoveEventInterceptor(napi_env env, napi_callback_info info) { Input_Result ret = OH_Input_RemoveInputEventInterceptor(); // ... } ## 完整示例 * [输入事件拦截（C/C++）](https://gitcode.com/openharmony/applications_app_samples/tree/master/code/DocsSample/InputKit/NDKInputEventInterceptor)