Question

有没有办法让对象在surfaceView中获得foregorund。

例如：

canvas.drawBitmap(...);
canvas.drawText(...);

如果我这样做，那么文字出现在位图上。如何在不重绘

的情况下撤消它

抱歉我的英文。

Answer 1

没有方法可以使元素正面和背面。您正尝试在此处更改元素的Z顺序，这是不可能的，或者Android中没有直接方法。您所能做的就是在布局中排列它们并启用和禁用视图，以便它们可以产生相同的效果您可以使用addView()或setVisibility(View.Visible)将元素带回前方。

Answer 2

请尝试使用以下代码。 // SurfaceView类公共类MainGamePanel扩展了SurfaceView实现 SurfaceHolder.Callback { MainThread线程;

public MainGamePanel(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
    getHolder().addCallback(this);
    setFocusable(true);
    thread = new MainThread(getHolder(), this);

}

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    // TODO Auto-generated method stub
    Log.e("N", "Changed");

}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    Log.e("N", "Created");
    thread.setRunning(true);
    thread.start();
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    Log.e("N", "Destroyed");
    boolean retry = true;
    while (retry) {
        try {
            thread.join();
            retry = false;
        } catch (InterruptedException e) {
            // try again shutting down the thread
        }
    }
}

public boolean onTouchEvent(MotionEvent event) {
    if (event.getAction() == MotionEvent.ACTION_DOWN) {
        if (event.getY() > getHeight() - 50) {
            thread.setRunning(false);
            ((Activity) getContext()).finish();
        } else {
            Log.d("N", "Coords: x=" + event.getX() + ",y=" + event.getY());
        }
    }
    return super.onTouchEvent(event);
}

}

// MainThread类

公共类MainThread扩展了线程{

// flag to hold game state
private boolean running;
private SurfaceHolder surfaceHolder;
private MainGamePanel gamePanel;

public void setRunning(boolean running) {
    this.running = running;
}

public MainThread(SurfaceHolder surfaceHolder, MainGamePanel gamePanel) {
    super();
    this.surfaceHolder = surfaceHolder;
    this.gamePanel = gamePanel;
}

@Override
public void run() {
    long tickCount = 0L;
    Log.d("N", "Starting game loop");
    while (running) {
        tickCount++;
        // update game state
        // render state to the screen
    }
    Log.d("N", "Game loop executed " + tickCount + " times");
}

} //主要活动

公共类MainActivity扩展了Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new MainGamePanel(this));
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

}

Answer 3

Canvas只是封装了位图对象，而位图只保存了某个位置的像素颜色，它不会保存单独的图层。这就像画MSPaint一样。因此，您无法在画布上更改基元的Z顺序。但是，为什么不改变命令的顺序呢？

如何在SurfaceView中将对象置于前面

3 个答案: