Question

我有一个表面视图，每当我触摸屏幕时，我触摸的位置会出现一个图像。这很棒，但我无法弄清楚如何在SurfaceView上放置背景。我已经尝试使用OnDraw立即绘制背景（无需触摸它），并且只在某些时候有效。它强制关闭大部分时间。

有人想查看我的代码并查看是否可以在Surface视图上获取背景图像？提前致谢。

类MyView扩展SurfaceView实现SurfaceHolder.Callback { 私人已经_thread; private ArrayList _graphicsz = new ArrayList（）; private GraphicObject _currentGraphic = null;

public MyView(Context context) {
    super(context);
    getHolder().addCallback(this);
    _thread = new Thready(getHolder(), this);
    setFocusable(true);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    synchronized (_thread.getSurfaceHolder()) {
        GraphicObject graphic = null;
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            graphic = new GraphicObject(BitmapFactory.decodeResource(getResources(), R.drawable.cat1small));
            graphic.getCoordinates().setX((int) event.getX() - graphic.getGraphic().getWidth() / 2);
            graphic.getCoordinates().setY((int) event.getY() - graphic.getGraphic().getHeight() / 2);
            _currentGraphic = graphic;
        } else if (event.getAction() == MotionEvent.ACTION_MOVE) {
            _currentGraphic.getCoordinates().setX((int) event.getX() - _currentGraphic.getGraphic().getWidth() / 2);
            _currentGraphic.getCoordinates().setY((int) event.getY() - _currentGraphic.getGraphic().getHeight() / 2);
        } else if (event.getAction() == MotionEvent.ACTION_UP) {
            _graphicsz.add(_currentGraphic);
            _currentGraphic = null;
        }

        return true;
    }
}

@Override
public void onDraw(Canvas canvas) {


    canvas.drawColor(Color.BLACK);
    Bitmap bitmap1;
    GraphicObject.Coordinates coords1;
    for (GraphicObject graphic : _graphicsz) {
        bitmap1 = graphic.getGraphic();
        coords1 = graphic.getCoordinates();
        canvas.drawBitmap(bitmap1, coords1.getX(), coords1.getY(), null);
    }
    // draw current graphic at last...
    if (_currentGraphic != null) {
        bitmap1 = _currentGraphic.getGraphic();
        coords1 = _currentGraphic.getCoordinates();
        canvas.drawBitmap(bitmap1, coords1.getX(), coords1.getY(), null);
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    // TODO Auto-generated method stub
}

public void surfaceCreated(SurfaceHolder holder) {
    _thread.setRunning(true);
    _thread.start();
}




public void surfaceDestroyed(SurfaceHolder holder) {
    // simply copied from sample application LunarLander:
    // we have to tell thread to shut down & wait for it to finish, or else
    // it might touch the Surface after we return and explode
    boolean retry = true;
    _thread.setRunning(false);
    while (retry) {
        try {
            _thread.join();
            retry = false;
        } catch (InterruptedException e) {
            // we will try it again and again...
        }
    }
}

}

class Thready extends Thread {     private SurfaceHolder _surfaceHolder;    私人MyView _panel;   private boolean _run = false;

public Thready(SurfaceHolder surfaceHolder, MyView panel) {
    _surfaceHolder = surfaceHolder;
    _panel = panel;
}

public void setRunning(boolean run) {
    _run = run;
}

public SurfaceHolder getSurfaceHolder() {
    return _surfaceHolder;
}

@Override
public void run() {
    Canvas c;
    while (_run) {
        c = null;
        try {
            c = _surfaceHolder.lockCanvas(null);
            synchronized (_surfaceHolder) {
                _panel.onDraw(c);
            }
        } finally {
            // do this in a finally so that if an exception is thrown
            // during the above, we don't leave the Surface in an
            // inconsistent state
            if (c != null) {
                _surfaceHolder.unlockCanvasAndPost(c);
            }
        }
    }
}

}

class GraphicObject {     / **     *包含图形的坐标。    * /   公共类坐标{     private int _x = 100;           private int _y = 0;

    public int getX() {
        return _x + _bitmap.getWidth() / 2;
    }

    public void setX(int value) {
        _x = value - _bitmap.getWidth() / 2;
    }

    public int getY() {
        return _y + _bitmap.getHeight() / 2;
    }

    public void setY(int value) {
        _y = value - _bitmap.getHeight() / 2;
    }

    public String toString() {
        return "Coordinates: (" + _x + "/" + _y + ")";
    }
}

private Bitmap _bitmap;
private Coordinates _coordinates;

public GraphicObject(Bitmap bitmap) {
    _bitmap = bitmap;
    _coordinates = new Coordinates();
}

public Bitmap getGraphic() {
    return _bitmap;
}

public Coordinates getCoordinates() {
    return _coordinates;
}

}

Answer 1

嗯，首先让我感到震惊的是什么（可能导致很多问题）是：

你经常创建新的位图

每当你接触到触摸事件时，你就会加载你的位图......你每秒可以获得80到100次触摸事件！

首先，定义全局位图（私有位图bmp1;等），将它们加载到其他地方，然后在触摸事件中使用它们。

此外，从onDraw中删除bmp加载/创建并将其移动到其他位置。

完成后，看看会发生什么;你可能有更多的问题（REALY快速扫描你的代码似乎没问题），但不是每秒80次创建和加载位图肯定有帮助:)

Android：SurfaceView上的背景？

1 个答案: