如何在表面视图中添加触控侦听器？

Question

我是Android的新手,所以请原谅以前是否有人问过!

我正在玩一些相机代码(在网上找到),我想在屏幕上显示/隐藏一些按钮.当用户触摸屏幕时,我希望它捕获图像.

我的设置:

1.主要活动:

public class CameraDemo extends Activity {
/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_inuse);

        preview = new Preview(this);

        ((FrameLayout) findViewById(R.id.preview)).addView(preview);

... ...  
// rest of the code that captures the image when a button is pressed.
// the button is defined in main.xml with button id ButtonClicked
}

2.预览类如下所示:

class Preview extends SurfaceView implements SurfaceHolder.Callback {

    SurfaceHolder mHolder;
    public Camera camera;

    Preview(Context context) {
        super(context);

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

我的问题是,

1. 如何添加触摸功能以便用户可以触摸预览(比如一秒钟,或者只是快速触摸)并且会发生什么？(说保存图像)

2. 例如,表面上会出现一个按钮,上面写着"下一步"按钮吗？

Answer 1

@Override
public boolean onTouchEvent(MotionEvent event) {
    return super.onTouchEvent(event);
}

在您的预览类中,MotionEvent对象将告诉您它是什么样的触摸(和位置等)并让您做任何您想做的事情.