Question

我目前正在使用一个Android应用程序，该应用程序允许我访问相机，并且单击一个按钮后，我便切换到了前摄像头。单击另一个按钮，回到后凸轮。但是，单击按钮时我遇到了问题。如果我在后凸轮上（启动应用程序时这是默认选项），然后单击前凸轮按钮，则凸轮会暂停。它保持暂停状态，直到我再次按下前面板按钮，然后切换到前面板。后凸轮也发生同样的情况。我检查了logcat，并说“相机空闲”。有人遇到过这样的问题吗？

谢谢

凸轮打开的方式是先通过openCamera（），然后再进入statecallback函数。

openCamera（）用于后凸轮。 switchCam（）用于前凸轮。我不知道如何切换凸轮，所以我使用了相同的功能，但是将索引从0更改为1。

private void openCamera() {
    CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);

    Log.e(TAG, "is camera open");
    try {
        cameraId = manager.getCameraIdList()[0];
        CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
        StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
        assert map != null;
        imageDimension = map.getOutputSizes(SurfaceTexture.class)[2];
        // Add permission for camera and let user grant the permission
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CAMERA_PERMISSION);
            return;
        }
       // manager.openCamera(cameraId, stateCallback, null);
        manager.openCamera(cameraId,stateCallback,null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
    Log.e(TAG, "openCamera X");
}


protected void switchCam() {
    CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    Log.e(TAG, "is camera open");
    try {
        cameraId = manager.getCameraIdList()[1];
        CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
        StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
        assert map != null;
        imageDimension = map.getOutputSizes(SurfaceTexture.class)[2];
        // Add permission for camera and let user grant the permission
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CAMERA_PERMISSION);
            return;
        }
        manager.openCamera(cameraId, stateCallback, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
    Log.e(TAG, "openCamera X");
}


private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
    @Override
    public void onOpened(CameraDevice camera) {
        //This is called when the camera is open
        Log.e(TAG, "onOpened");

        cameraDevice = camera;

        createCameraPreview();
    }



    @Override
    public void onDisconnected(CameraDevice camera) {
        cameraDevice.close();
    }

    @Override
    public void onError(CameraDevice camera, int error) {
        cameraDevice.close();
        cameraDevice = null;
    }


    public void onPause(CameraDevice camera){
        cameraDevice=camera;
    }
};

在访问相机之前，我需要按两次按钮

0 个答案: