了解Android中Camera2Basic中camera2 API中的按钮单击

Question

I'm trying to understand how the camera2 api works in the Google Camera2Basic sample code. Specifically, how does the 'Picture' button register the shot?

In onCreateViewCreated:

@Override
public void onViewCreated(final View view, Bundle savedInstanceState) {
    view.findViewById(R.id.picture).setOnClickListener(this);
    view.findViewById(R.id.info).setOnClickListener(this);
    mTextureView = (AutoFitTextureView) view.findViewById(R.id.texture);
}

So setOnClickListener() registers the click? But what does it go to? I see that this is passed in but I don't understand what's going on.

What I've normally done is do something like set up a button in onCreateView() and wire its setOnClickListener() to some action like so:

photoButton = (Button)v.findViewById(R.id.picture);
photoButton.setOnClickListener(new View.onSetClickListener() {
    @Override
    public void onClick(View v) {
        //some action
    }
});

Answer 1

This same thing is happening in the example code. However, it looks a little different because the Camera2BasicFragment activity is implementing OnClickListener . Therefore, when the onClickListener is set, this is given to say that this activity will override the onClick method. So when the button is clicked the onClick method in the class is automatically called.

@Override
public void onClick(View view) {
    switch (view.getId()) {
        case R.id.picture: {
            takePicture();
            break;
        }
        case R.id.info: {
            Activity activity = getActivity();
            if (null != activity) {
                new AlertDialog.Builder(activity)
                        .setMessage(R.string.intro_message)
                        .setPositiveButton(android.R.string.ok, null)
                        .show();
            }
            break;
        }
    }
}