安卓4-图形与多个线程

Question

我有一个绘图程序的骨架，使用一个线程：

    @Override
public void surfaceCreated( SurfaceHolder holder) {
    pajeuThread = new PageThread( holder);
    pajeuThread.setRunning(true);
    Log.v(TAG, "surfaceCreated"  );
    pajeuThread.start();
} // end method surfaceCreated

然后我在页面中心附近写下"Hello World"，然后在页面左侧写下一个递增30的数字，如下所示：

public void dessineArbre( Canvas canvasse ) {
    compteur += 30;
    if ( compteur > 500 ) compteur = 30;
    screenWidth = getWidth();
    screenHeight = getHeight();
    Log.v(TAG, "dessineArbre"  );
    pagePaint.setColor( Color.WHITE);
    canvasse.drawRect(0, 0, screenWidth, screenHeight, pagePaint);
    pagePaint.setColor( Color.GREEN);
    canvasse.drawText( "Hello World", 200, 200, pagePaint);
    canvasse.drawText(Integer.toString( compteur ), 10, compteur, pagePaint);
} // end method dessineArbre

我想用第二根线画出数字。

线程由内部类以这种方式处理：

        private class PageThread extends Thread {
    private SurfaceHolder surfaceHoldere;
    private boolean threadIsRunning = true;
    public PageThread( SurfaceHolder holdere){
        surfaceHoldere = holdere;
        setName( "page thread");
    } // end constructor
    public void setRunning( boolean runninge)   {
        threadIsRunning = runninge;
    } // end setRunning
    @Override
    public void run() {
        Canvas canvasvas = null;
        while( threadIsRunning ) {
            try {
                canvasvas = surfaceHoldere.lockCanvas(null);
                synchronized( surfaceHoldere) {
                    Log.v(TAG, "PageThread try synchronized"  );
                    dessineArbre( canvasvas);
                }// end synchronized
            } // end try
            finally {
                if( canvasvas != null)
                    Log.v(TAG, "Pagethread finally"  );
                    surfaceHoldere.unlockCanvasAndPost(canvasvas);
            } // end finally
        } // end while
    } // end method run
} // end class Pagethread

如何创建此类Pagethread的另一个对象？

Answer 1

我找到了一种方法来创建第二个线程，并使其睡眠1000毫秒

    private PageThread pajeuThread;
private PageThread pajeuThread2;
    .
    .
@Override
public void surfaceCreated( SurfaceHolder holder) {
    pajeuThread = new PageThread( holder);
    pajeuThread.setRunning(true);
    pajeuThread2 = new PageThread( holder);
    pajeuThread2.setRunning(true);
    Log.v(TAG, "surfaceCreated"  );
    pajeuThread.start();
} // end method surfaceCreated

（我没有启动（）pajeuThread2，但它仍然有效。）

public void dessineArbre( Canvas canvasse ) {
    screenWidth = getWidth();
    screenHeight = getHeight();
    Log.v(TAG, "dessineArbre"  );
    pagePaint.setColor( Color.WHITE);
    canvasse.drawRect(0, 0, screenWidth, screenHeight, pagePaint);
    pagePaint.setColor( Color.GREEN);
    canvasse.drawText( "Hello World", 200, 200, pagePaint);
} // end method dessineArbre
public void drawCounter( Canvas canvassed ) {
    compteur += 30;
    if ( compteur > 500 ) compteur = 30;
    Log.v(TAG, "drawCounter"  );
    pagePaint.setColor( Color.GREEN);
    canvassed.drawText(Integer.toString( compteur ), 10, compteur, pagePaint);
    try{
       pajeuThread2.sleep( 1000);
    }
    catch( InterruptedException e) {
        Log.v(TAG, "drawCounter exception"  );
    }
} // end method drawCounter 

我添加了对drawCounter方法的调用：

    private class PageThread extends Thread {
    private SurfaceHolder surfaceHoldere;
    private boolean threadIsRunning = true;
    public PageThread( SurfaceHolder holdere){
        surfaceHoldere = holdere;
        setName( "page thread");
    } // end constructor
    public void setRunning( boolean runninge)   {
        threadIsRunning = runninge;
    } // end setRunning
    @Override
    public void run() {
        Canvas canvasvas = null;
        while( threadIsRunning ) {
            try {
                canvasvas = surfaceHoldere.lockCanvas(null);
                synchronized( surfaceHoldere) {
                    Log.v(TAG, "PageThread try synchronized"  );
                    dessineArbre( canvasvas);
                    drawCounter( canvasvas );
                }// end synchronized
            } // end try
            finally {
                if( canvasvas != null)
                    Log.v(TAG, "Pagethread finally"  );
                    surfaceHoldere.unlockCanvasAndPost(canvasvas);
            } // end finally
        } // end while
    } // end method run
} // end class Pagethread

这很好，但我不确定这是否是管理线程的正确方式。

非常感谢您的帮助