未触发OnDraw(),surfaceView中未绘制任何内容-Android

概述嗨！我在水平滚动视图中有一个SurfaceView,我想通过onDraw()调用来填充图像.但是,什么也没画.我有一个类,其中的绘图是通过CanvasThread线程完成的.publicclassPanelChartextendsSurfaceViewimplementsSurfaceHolder.Callback{privateCanvasThreadcanvasthread;public

嗨！我在水平滚动视图中有一个SurfaceVIEw,我想通过onDraw()调用来填充图像.但是,什么也没画.
我有一个类,其中的绘图是通过CanvasThread线程完成的.

public class PanelChart extends SurfaceVIEw implements SurfaceHolder.Callback {private CanvasThread canvasthread ;public PanelChart(Context context, AttributeSet attrs) {    super(context, attrs);    // Todo auto-generated constructor stubgetHolder().addCallback(this);canvasthread = new CanvasThread(getHolder(), this);setFocusable(true);

我试图改变

`synchronized (_surfaceHolder) {                      _panel.postInvalIDate();                    }`

至
已同步(_surfaceHolder){
                          _panel.postInvalIDate();
                        }

我也尝试添加调用setwillNotDraw(false)而不走运：

 @OverrIDepublic voID surfaceCreated(SurfaceHolder holder) {        // Todo auto-generated method stub    canvasthread.setRunning(true);    canvasthread.start();   setwillNotDraw(false);

这似乎是一个常见问题,但是我遇到的所有解决方案都没有对我有用.

谢谢！

解决方法:

postInvalIDate不会使用surfaceVIEw调用onDraw.您需要解锁画布,绘制事物,然后锁定画布.这是surfaceVIEw线程的示例：

    class CanvasThread extends Thread {        private SurfaceHolder surfaceHolder;        private PanelChart panel;        private boolean run = false;        public CanvasThread(SurfaceHolder surfaceHolder, PanelChart panel) {            this.surfaceHolder = surfaceHolder;            this.panel = panel;        }        public voID setRunning(boolean run) {            this.run = run;        }        public SurfaceHolder getSurfaceHolder() {            return surfaceHolder;        }        @OverrIDe        public voID run() {            Canvas c;            while (run) {                c = null;                //limit the frame rate to maximum 60 frames per second (16 miliseconds)                timeNow = System.currentTimeMillis();                timedelta = timeNow - timePrevFrame;                if ( timedelta < 16){                    try{                        Thread.sleep(16 - timedelta);                    }catch(InterruptedException e){                    }                }                timePrevFrame = System.currentTimeMillis();                try {                    c = surfaceHolder.lockCanvas(null);                    synchronized (surfaceHolder) {                        panel.onDraw(c); //draw canvas                         computePhysics(); //calculate next frame                    }                } finally {                    if (c != null) {                        surfaceHolder.unlockCanvasAndPost(c);  //show canvas                    }                }//try finally              } //while        }//run    }//thread

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