安卓相机 API 2 手动对焦与触摸

Question

我想制作具有触摸焦点的相机应用程序，但我对相机 API 2 有点困惑。我已经阅读了有关LENS_FOCUS_DISTANCE但我不知道如何使用它。你能帮忙吗？

提前感谢您，祝您周末愉快！

Answer 1

Camera API2 一开始看起来很奇怪，但随后你会发现它非常简单。

此问题的最佳答案是带有注释的代码：

private void captureImage() {
    try {
        //for do this you should have mCameraDevice and mCameraCaptureSession
        //get CaptureRequestBuilder.
        captureStillBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
        //add target surfaces - for getting image data you should have instance on ImageReader
        //with OnImageAvailableListener that will be called when image will be captured
        //but for showing on screen you have to use SurfaceView or TextureView
        captureStillBuilder.addTarget(mImageReader.getSurface());
        //add some details for Request
        //in general: you have fields and values for it and you just set what value should be in each field
        // auto focus works only when whole control mode in auto
        captureStillBuilder.set(CaptureRequest.CONTROL_MODE, CaptureRequest.CONTROL_MODE_AUTO);
        // before capture lock focus
        captureStillBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,
                CaptureRequest.CONTROL_AF_TRIGGER_START);
        // set area for focusing
        MeteringRectangle[] focusArea = new MeteringRectangle[1];            
        focusArea[0] = new MeteringRectangle(/*here set coordinates for focus on */);
        captureStillBuilder.set(CaptureRequest.CONTROL_AF_REGIONS, focusArea);
        // create callback for this capture
        CameraCaptureSession.CaptureCallback callback = new ...
        // just run capture to make focused photo
        mCameraCaptureSession.capture(captureStillBuilder.build(), callback, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}