android - 手电筒相机2 API

Question

我可以在Android Camera2 API中同时使用相机预览和手电筒吗？

当我尝试使用CameraManager.setTorchMode(StringcameraId, booleanenabled)时，当相机未打开时它工作正常。但是当相机打开并且我尝试 setTorchMode 时，我收到此异常:

CameraService: setTorchMode: torch mode of camera 0 is not available because camera is in use

Answer 1

设置 FLASH_MODE 和 AE_MODE 很重要。下面是工作代码:

public void toggleFlashMode(boolean enable){
try {
            if (mCameraType.equals(CameraType.BACK)) {
                if (enable) {
                    mPreviewRequestBuilder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_TORCH);
                    mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON);
                } else {
                    mPreviewRequestBuilder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_OFF);
                    mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_OFF);
                }
                mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), null, null);
            }
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
}