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 .
有人想看看我的代码,看看是否有可能在Surface视图上获得背景图像?提前致谢 .
类MyView扩展SurfaceView实现SurfaceHolder.Callback {private Thready _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 . * / public class Coordinates {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;
}
}
1 回答
那么,首先让我感到震惊的是什么(以及可能造成很多问题的原因)是这样的:
你经常创建新的位图方式
每当你接触到触摸事件时,你就会加载你的位图......你每秒钟可以获得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 .
另外,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很好),但不是每秒80次创建和加载位图肯定会有帮助:)