Android Camera Api 2 触摸手动对焦

Question

我想制作带有触摸对焦的相机应用程序，但我对相机 API 2 有点困惑。我已经阅读了有关 LENS_FOCUS_DISTANCE 的内容，但我不明白如何使用它。你能帮忙吗？

在此先感谢您，祝您周末愉快!

Answer 1

Camera API2 开始时看起来很奇怪，但随后您会发现它非常简单。

这个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();
    }
}