跳到主要内容

使用Image_NativeModule完成图片接收

图像接收类,用于获取组件的surfaceId、接收最新的图片、读取下一张图片以及释放ImageReceiver实例。结合camera API实现的相机预览示例代码可参考预览流二次处理(C/C++)

ImageReceiver只作为图片的接收方、消费者,在ImageReceiver设置的size、format等属性实际上并不会生效。图片属性需要在发送方、生产者进行设置,可参考预览(C/C++)设置previewProfiles。

开发步骤

添加依赖

在进行应用开发之前,开发者需要打开native工程的src/main/cpp/CMakeLists.txt,在target_link_libraries依赖中添加libohimage.so、libimage_receiver.so、libnative_image.so以及日志依赖libhilog_ndk.z.so。

target_link_libraries(entry PUBLIC libhilog_ndk.z.so libohimage.so libimage_receiver.so libnative_image.so)

Native接口调用

具体接口说明请参考Image_NativeModule

下述代码主要演示了Receiver的初始化、相机预览流的创建以及获取图像的信息和Receiver的释放等相关功能。

部分接口在API version 20以后才支持,需要开发者在进行开发时选择合适的API版本。

  1. 导入相关头文件。

    #include <hilog/log.h>
    #include "napi/native_api.h"
    #include <string>
    #include <multimedia/image_framework/image/image_native.h>
    #include <multimedia/image_framework/image/image_receiver_native.h>

    #include "ohcamera/camera.h"
    #include "ohcamera/camera_input.h"
    #include "ohcamera/capture_session.h"
    #include "ohcamera/photo_output.h"
    #include "ohcamera/preview_output.h"
    #include "ohcamera/video_output.h"
    #include "ohcamera/camera_manager.h"

    #include <mutex>
    #include <shared_mutex> // C++17以上使用
    #include <condition_variable>
  2. 常量定义。

    #undef LOG_DOMAIN
    #define LOG_DOMAIN 0x3200

    #undef LOG_TAG
    #define LOG_TAG "MY_TAG"

    #define IMAGE_WIDTH 320
    #define IMAGE_HEIGHT 480
    #define IMAGE_CAPACITY 2
  3. 定义全局变量。

    static OH_ImageReceiverNative* g_receiver = nullptr;

    static std::mutex g_mutex;
    static std::shared_mutex shared_receiver_mutex;
    static std::condition_variable g_condVar;
    static bool g_imageReady = false;
    static OH_ImageNative* g_imageInfoResult = nullptr;
  4. 定义一些工具类函数,用来处理napi的返回值和参数类型的转换。

    // 处理napi返回值。
    napi_value GetJsResultDemo(napi_env env, int result)
    {
    napi_value resultNapi = nullptr;
    napi_create_int32(env, result, &resultNapi);
    return resultNapi;
    }

    // 将uint64_t转换为一个以null结尾的char数组。
    std::unique_ptr<char[]> ConvertUint64ToCharTemp(uint64_t value)
    {
    std::string strValue = std::to_string(value);
    auto charBuffer = std::make_unique<char[]>(strValue.size() + 1);
    std::copy(strValue.begin(), strValue.end(), charBuffer.get());
    charBuffer[strValue.size()] = '\0';

    return charBuffer;
    }
  5. 初始化Receiver。

    • 创建并设置ReceiverOptions。

      static Image_ErrorCode CreateAndConfigOptions(OH_ImageReceiverOptions** options)
      {
      Image_ErrorCode errCode = OH_ImageReceiverOptions_Create(options);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Create image receiver options failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      Image_Size imgSize = {IMAGE_WIDTH, IMAGE_HEIGHT};
      errCode = OH_ImageReceiverOptions_SetSize(*options, imgSize);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Set image receiver options size failed, errCode: %{public}d.", errCode);
      OH_ImageReceiverOptions_Release(*options);
      return errCode;
      }
      errCode = OH_ImageReceiverOptions_SetCapacity(*options, IMAGE_CAPACITY);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Set image receiver options capacity failed, errCode: %{public}d.", errCode);
      OH_ImageReceiverOptions_Release(*options);
      return errCode;
      }
      return IMAGE_SUCCESS;
      }
    • 获取ReceiverOptions。

      static Image_ErrorCode ValidateOptions(OH_ImageReceiverOptions* options)
      {
      Image_Size imgSizeRead;
      Image_ErrorCode errCode = OH_ImageReceiverOptions_GetSize(options, &imgSizeRead);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Get image receiver options size failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      if (imgSizeRead.width != IMAGE_WIDTH || imgSizeRead.height != IMAGE_HEIGHT) {
      OH_LOG_ERROR(LOG_APP, "Get image receiver options size failed,"
      "width: %{public}d, height: %{public}d.", imgSizeRead.width, imgSizeRead.height);
      return IMAGE_BAD_PARAMETER;
      }
      int32_t capacity = 0;
      errCode = OH_ImageReceiverOptions_GetCapacity(options, &capacity);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Get image receiver options capacity failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      if (capacity != IMAGE_CAPACITY) {
      OH_LOG_ERROR(LOG_APP, "Get image receiver options capacity failed, capacity: %{public}d.", capacity);
      return IMAGE_BAD_PARAMETER;
      }
      return IMAGE_SUCCESS;
      }
    • 创建Receiver对象。

      static Image_ErrorCode CreateReceiver(OH_ImageReceiverOptions* options, OH_ImageReceiverNative** receiver)
      {
      Image_ErrorCode errCode = OH_ImageReceiverNative_Create(options, receiver);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Create image receiver failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      return IMAGE_SUCCESS;
      }
    • 定义获取下一张图片的callback函数。

      static void OnCallback(OH_ImageReceiverNative* receiver)
      {
      OH_LOG_INFO(LOG_APP, "ImageReceiverNativeCTest buffer available.");

      // 共享锁(读)
      std::shared_lock<std::shared_mutex> lock(shared_receiver_mutex);
      OH_ImageNative* image = nullptr;
      Image_ErrorCode errCode = OH_ImageReceiverNative_ReadNextImage(receiver, &image);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "ImageReceiverNativeCTest get image receiver next image failed,"
      "errCode: %{public}d.", errCode);
      OH_ImageNative_Release(image);
      return;
      } else {
      std::lock_guard<std::mutex> lock(g_mutex);
      g_imageInfoResult = image;
      g_imageReady = true;
      }
      g_condVar.notify_one();
      }
    • 注册callback。

      static Image_ErrorCode RegisterCallbackAndQuery(OH_ImageReceiverNative* receiver)
      {
      uint64_t surfaceID = 0;
      Image_ErrorCode errCode = OH_ImageReceiverNative_On(receiver, OnCallback);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Image receiver on failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      errCode = OH_ImageReceiverNative_GetReceivingSurfaceId(receiver, &surfaceID);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Get image receiver surfaceID failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      OH_LOG_INFO(LOG_APP, "Get image receiver surfaceID: %{public}lu.", surfaceID);
      Image_Size imgSizeRead;
      errCode = OH_ImageReceiverNative_GetSize(receiver, &imgSizeRead);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Get image receiver size failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      OH_LOG_INFO(LOG_APP, "Get image receiver size: width = %{public}d, height = %{public}d.",
      imgSizeRead.width, imgSizeRead.height);
      int32_t capacity = 0;
      errCode = OH_ImageReceiverNative_GetCapacity(receiver, &capacity);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Get image receiver capacity failed, errCode: %{public}d.", errCode);
      return errCode;
      }
      OH_LOG_INFO(LOG_APP, "Get image receiver capacity: %{public}d.", capacity);
      return IMAGE_SUCCESS;
      }
    • 初始化Receiver的整体流程。

      static napi_value ImageReceiverNativeCTest(napi_env env, napi_callback_info info)
      {
      if (g_receiver != nullptr) {
      OH_ImageReceiverNative_Off(g_receiver);
      OH_ImageReceiverNative_Release(g_receiver);
      g_receiver = nullptr;
      }

      OH_ImageReceiverOptions* options = nullptr;
      Image_ErrorCode errCode = CreateAndConfigOptions(&options);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "CreateAndConfigOptions failed errCode=%{public}d", errCode);
      return GetJsResultDemo(env, errCode);
      }
      errCode = ValidateOptions(options);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "ValidateOptions failed errCode=%{public}d", errCode);
      OH_ImageReceiverOptions_Release(options);
      return GetJsResultDemo(env, errCode);
      }
      errCode = CreateReceiver(options, &g_receiver);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "CreateReceiver failed errCode=%{public}d", errCode);
      OH_ImageReceiverOptions_Release(options);
      return GetJsResultDemo(env, errCode);
      }
      errCode = RegisterCallbackAndQuery(g_receiver);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "RegisterCallbackAndQuery failed errCode=%{public}d", errCode);
      OH_ImageReceiverOptions_Release(options);
      OH_ImageReceiverNative_Release(g_receiver);
      g_receiver = nullptr;
      return GetJsResultDemo(env, errCode);
      }
      OH_LOG_INFO(LOG_APP, "ImageReceiverNativeCTest create and config success.");
      OH_ImageReceiverOptions_Release(options);
      return GetJsResultDemo(env, IMAGE_SUCCESS);
      }
  6. 调用相机拍照流进行拍照,触发回调。

    • 创建一个CameraManager实例。

      Camera_ErrorCode InitCameraManagerAndInput(Camera_Manager*& cameraManager,
      Camera_Device*& cameras,
      uint32_t& size,
      Camera_Input*& cameraInput)
      {
      cameraManager = nullptr;
      cameras = nullptr;
      size = 0;
      cameraInput = nullptr;
      Camera_ErrorCode ret = OH_Camera_GetCameraManager(&cameraManager);
      if (cameraManager == nullptr || ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_Camera_GetCameraManager failed.");
      return ret;
      }
      ret = OH_CameraManager_GetSupportedCameras(cameraManager, &cameras, &size);
      if (cameras == nullptr || size < 1 || ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedCameras failed.");
      return ret;
      }

      for (uint32_t i = 0; i < size; ++i) {
      OH_LOG_INFO(LOG_APP, "Camera[%{public}u]: id=%{public}s, position=%{public}d, type=%{public}d, "
      "connectionType=%{public}d", i, cameras[i].cameraId, cameras[i].cameraPosition, cameras[i].cameraType,
      cameras[i].connectionType);
      }

      ret = OH_CameraManager_CreateCameraInput(cameraManager, &cameras[0], &cameraInput);
      if (cameraInput == nullptr || ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateCameraInput failed.ret:%{public}d", ret);
      return ret;
      }
      return CAMERA_OK;
      }
    • 获取相机输出能力。

      Camera_ErrorCode GetCameraOutputCapability(Camera_Manager* cameraManager,
      Camera_Device* cameras,
      uint32_t cameraDeviceIndex,
      Camera_OutputCapability*& capability)
      {
      capability = nullptr;
      Camera_ErrorCode ret = OH_CameraManager_GetSupportedCameraOutputCapability(cameraManager,
      &cameras[cameraDeviceIndex],
      &capability);
      if (capability == nullptr || ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedCameraOutputCapability failed.");
      }
      return ret;
      }
    • 创建相机捕获会话,用于捕获相机拍摄的照片。

      Camera_CaptureSession* CreateAndStartSession(Camera_Manager* cameraManager, Camera_Input* cameraInput, int sessionMode)
      {
      Camera_CaptureSession* captureSession = nullptr;
      Camera_ErrorCode ret = OH_CameraManager_CreateCaptureSession(cameraManager, &captureSession);
      if (captureSession == nullptr || ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateCaptureSession failed.");
      return nullptr;
      }
      ret = OH_CaptureSession_SetSessionMode(captureSession, static_cast<Camera_SceneMode>(sessionMode));
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_SetSessionMode failed.");
      return nullptr;
      }
      ret = OH_CaptureSession_BeginConfig(captureSession);
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_BeginConfig failed.");
      return nullptr;
      }
      ret = OH_CaptureSession_AddInput(captureSession, cameraInput);
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddInput failed.");
      return nullptr;
      }
      return captureSession;
      }
    • 开启捕获会话。

      static Camera_ErrorCode StartCaptureSession(Camera_Manager* mgr, Camera_Input* input,
      Camera_PreviewOutput* previewOutput,
      Camera_CaptureSession** sessionOut)
      {
      *sessionOut = CreateAndStartSession(mgr, input, NORMAL_PHOTO);
      if (*sessionOut == nullptr) {
      OH_LOG_ERROR(LOG_APP, "CreateAndStartSession failed.");
      return CAMERA_INVALID_ARGUMENT;
      }

      Camera_ErrorCode ret = OH_CaptureSession_AddPreviewOutput(*sessionOut, previewOutput);
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddPreviewOutput failed.");
      return ret;
      }

      ret = OH_CaptureSession_CommitConfig(*sessionOut);
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_CommitConfig failed.");
      return ret;
      }

      ret = OH_CaptureSession_Start(*sessionOut);
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Start failed.");
      }

      return ret;
      }
    • 创建相机拍照流。

      Camera_ErrorCode StartTakePhoto(char* str)
      {
      char* photoSurfaceId = str;
      Camera_Manager* cameraManager = nullptr;
      Camera_Device* cameras = nullptr;
      uint32_t size = 0;
      Camera_Input* cameraInput = nullptr;
      Camera_ErrorCode ret = InitCameraManagerAndInput(cameraManager, cameras, size, cameraInput);
      if (ret != CAMERA_OK) return ret;

      Camera_OutputCapability* cameraOutputCapability = nullptr;
      ret = GetCameraOutputCapability(cameraManager, cameras, 0, cameraOutputCapability);
      if (ret != CAMERA_OK) return ret;

      const Camera_Profile* photoProfile = cameraOutputCapability->previewProfiles[0];
      Camera_PreviewOutput* previewOutput = nullptr;
      ret = OH_CameraManager_CreatePreviewOutput(cameraManager, photoProfile, photoSurfaceId, &previewOutput);
      if (photoProfile == nullptr || previewOutput == nullptr || ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreatePreviewOutput failed.");
      return ret;
      }

      ret = OH_CameraInput_Open(cameraInput);
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "OH_CameraInput_open failed.");
      return ret;
      }

      Camera_CaptureSession* captureSession = nullptr;
      ret = StartCaptureSession(cameraManager, cameraInput, previewOutput, &captureSession);
      if (ret != CAMERA_OK) {
      OH_LOG_ERROR(LOG_APP, "StartCaptureSession failed.");
      return ret;
      }

      return CAMERA_OK;
      }
    • 调用相机拍照的整体流程。

      static napi_value TakePhoto(napi_env env, napi_callback_info info)
      {
      if (g_receiver == nullptr) {
      OH_LOG_ERROR(LOG_APP, "ImageReceiver not initialized.");
      return GetJsResultDemo(env, IMAGE_BAD_PARAMETER);
      }
      uint64_t surfaceId = 0;
      Image_ErrorCode errCode = OH_ImageReceiverNative_GetReceivingSurfaceId(g_receiver, &surfaceId);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "Get surfaceId failed.");
      return GetJsResultDemo(env, errCode);
      }

      auto surfaceId_c = ConvertUint64ToCharTemp(surfaceId);
      Camera_ErrorCode photoRet = StartTakePhoto(surfaceId_c.get());
      return GetJsResultDemo(env, photoRet);
      }
  7. 获取Receiver接收到的图片信息。

    • 等待OnCallback回调通知。

      // 同步等待。
      static OH_ImageNative* NotifyJsImageInfoSync()
      {
      std::unique_lock<std::mutex> lock(g_mutex);
      g_imageReady = false;
      g_imageInfoResult = nullptr;

      // 等待OnCallback回调通知。
      bool ret = g_condVar.wait_for(lock, std::chrono::seconds(1), [] {
      OH_LOG_INFO(LOG_APP, "NotifyJsImageInfoSync: wait_for wakeup, g_imageReady=%{public}d", g_imageReady);
      return g_imageReady;
      });
      if (!ret) {
      OH_LOG_ERROR(LOG_APP, "NotifyJsImageInfoSync: wait_for timeout.");
      return nullptr;
      }
      return g_imageInfoResult;
      }
    • 获取图片大小。

      // 获取图片大小。
      static napi_value GetImageSizeInfo(napi_env env, OH_ImageNative* image)
      {
      OH_LOG_INFO(LOG_APP, "GetImageSizeInfo: enter, image=%{public}p", image);

      Image_Size imgSizeRead;
      Image_ErrorCode errCode = OH_ImageNative_GetImageSize(image, &imgSizeRead);
      OH_LOG_INFO(LOG_APP, "GetImageSizeInfo: GetImageSize errCode=%{public}d, width=%{public}d, height=%{public}d",
      errCode, imgSizeRead.width, imgSizeRead.height);

      if (errCode == IMAGE_SUCCESS) {
      napi_value resultObj;
      napi_create_object(env, &resultObj);

      napi_value width;
      napi_value height;
      napi_create_int32(env, imgSizeRead.width, &width);
      napi_create_int32(env, imgSizeRead.height, &height);

      napi_set_named_property(env, resultObj, "width", width);
      napi_set_named_property(env, resultObj, "height", height);

      OH_LOG_INFO(LOG_APP, "GetImageSizeInfo: exit");
      return resultObj;
      }

      OH_LOG_ERROR(LOG_APP, "GetImageSizeInfo: Failed to get image size");
      return nullptr;
      }
    • 获取组件类型。

      // 获取组件类型。
      static size_t GetComponentTypeSize(OH_ImageNative* image, size_t& componentTypeSize)
      {
      OH_LOG_INFO(LOG_APP, "GetComponentTypeSize: enter, image=%{public}p", image);
      // 获取组件类型的大小。
      Image_ErrorCode errCode = OH_ImageNative_GetComponentTypes(image, nullptr, &componentTypeSize);
      OH_LOG_INFO(LOG_APP, "GetComponentTypeSize: GetComponentTypes (query size) errCode=%{public}d,"
      "componentTypeSize=%{public}zu", errCode, componentTypeSize);
      return componentTypeSize;
      }
    • 获取组件信息。

      // 获取组件信息。
      static napi_value GetComponentInfo(napi_env env, size_t componentTypeSize, OH_ImageNative* image, napi_value resultObj)
      {
      if (componentTypeSize > 0) {
      uint32_t* components = new uint32_t[componentTypeSize];
      Image_ErrorCode errCode = OH_ImageNative_GetComponentTypes(image, &components, &componentTypeSize);
      OH_LOG_INFO(LOG_APP, "GetImageInfoObject: GetComponentTypes (get types) errCode=%{public}d,"
      "firstComponent=%{public}u", errCode, componentTypeSize > 0 ? components[0] : 0);
      if (errCode != IMAGE_SUCCESS) {
      OH_LOG_ERROR(LOG_APP, "GetImageInfoObject: GetComponentTypes (get types) failed");
      delete [] components;
      return resultObj;
      }

      OH_NativeBuffer* nativeBuffer = nullptr;
      errCode = OH_ImageNative_GetByteBuffer(image, components[0], &nativeBuffer);
      if (errCode == IMAGE_SUCCESS) {
      OH_LOG_INFO(LOG_APP, "Get native buffer success.");
      }

      size_t nativeBufferSize = 0;
      errCode = OH_ImageNative_GetBufferSize(image, components[0], &nativeBufferSize);
      OH_LOG_INFO(LOG_APP, "GetImageInfoObject: GetBufferSize errCode=%{public}d, nativeBufferSize=%{public}zu",
      errCode, nativeBufferSize);
      if (errCode == IMAGE_SUCCESS) {
      napi_value bufSize;
      napi_create_int32(env, static_cast<int32_t>(nativeBufferSize), &bufSize);
      napi_set_named_property(env, resultObj, "bufferSize", bufSize);
      }

      int32_t rowStride = 0;
      errCode = OH_ImageNative_GetRowStride(image, components[0], &rowStride);
      OH_LOG_INFO(LOG_APP, "GetImageInfoObject: GetRowStride errCode=%{public}d,"
      "rowStride=%{public}d", errCode, rowStride);
      if (errCode == IMAGE_SUCCESS) {
      napi_value jsRowStride;
      napi_create_int32(env, rowStride, &jsRowStride);
      napi_set_named_property(env, resultObj, "rowStride", jsRowStride);
      }

      int32_t pixelStride = 0;
      errCode = OH_ImageNative_GetPixelStride(image, components[0], &pixelStride);
      OH_LOG_INFO(LOG_APP, "GetImageInfoObject: GetPixelStride errCode=%{public}d, pixelStride=%{public}d",
      errCode, pixelStride);
      if (errCode == IMAGE_SUCCESS) {
      napi_value jsPixelStride;
      napi_create_int32(env, pixelStride, &jsPixelStride);
      napi_set_named_property(env, resultObj, "pixelStride", jsPixelStride);
      }
      delete [] components;
      }
      return resultObj;
      }
    • 获取图片属性并封装为napi对象。

      // 获取图像属性并封装为napi对象。
      static napi_value GetImageInfoObject(napi_env env, OH_ImageNative* image)
      {
      OH_LOG_INFO(LOG_APP, "GetImageInfoObject: enter, image=%{public}p", image);
      napi_value resultObj;
      napi_create_object(env, &resultObj);
      resultObj = GetImageSizeInfo(env, image);

      size_t componentTypeSize = 0;
      componentTypeSize = GetComponentTypeSize(image, componentTypeSize);
      if (componentTypeSize > 0) {
      resultObj = GetComponentInfo(env, componentTypeSize, image, resultObj);
      }

      int64_t timestamp = 0;
      Image_ErrorCode errCode = OH_ImageNative_GetTimestamp(image, &timestamp);
      OH_LOG_INFO(LOG_APP, "GetImageInfoObject: GetTimestamp errCode=%{public}d, timestamp=%{public}ld",
      errCode, timestamp);
      if (errCode == IMAGE_SUCCESS) {
      napi_value jsTimestamp;
      napi_create_int64(env, timestamp, &jsTimestamp);
      napi_set_named_property(env, resultObj, "timestamp", jsTimestamp);
      }

      OH_LOG_INFO(LOG_APP, "GetImageInfoObject: exit");
      return resultObj;
      }
    • 获取ReceiverImageInfo的整体流程。

      static napi_value GetReceiverImageInfo(napi_env env, napi_callback_info info)
      {
      OH_ImageNative* image = NotifyJsImageInfoSync();
      if (!image) {
      napi_value undefined;
      napi_get_undefined(env, &undefined);
      return undefined;
      }
      napi_value resultObj = GetImageInfoObject(env, image);
      OH_ImageNative_Release(image);
      return resultObj;
      }
  8. 释放receiver。

    static napi_value ReleaseImageReceiver(napi_env env, napi_callback_info info)
    {
    if (g_receiver == nullptr) {
    OH_LOG_INFO(LOG_APP, "No image receiver to release.");
    return nullptr;
    }

    Image_ErrorCode errCode = OH_ImageReceiverNative_Off(g_receiver);
    if (errCode != IMAGE_SUCCESS) {
    OH_LOG_ERROR(LOG_APP, "ImageReceiverNativeCTest image receiver off failed, errCode: %{public}d.", errCode);
    }

    // 独占锁(写)
    std::unique_lock<std::shared_mutex> lock(shared_receiver_mutex);
    errCode = OH_ImageReceiverNative_Release(g_receiver);
    if (errCode != IMAGE_SUCCESS) {
    OH_LOG_ERROR(LOG_APP, "Release image receiver failed, errCode: %{public}d.", errCode);
    }

    g_receiver = nullptr;
    return GetJsResultDemo(env, errCode);
    }