当我使用drawBitmap（）时的视觉缺陷

Question

在仿真器和电话中看起来像this。它总是一个随机的方块，被打破。

这里是从SurfaceView类的代码，最相关的部分是在prepareBackground（）：

代码开始：

公共类MenuBackgroundView扩展SurfaceView实现SurfaceHolder.Callback {

private Paint mPaint; 
private Bitmap blocks12x12; 
private boolean draw = false; 
private Context ctx; 
//private int begOffX; 
private int offX; 
private int offY; 
private int mWidth = 1; 
private int mHeight = 1; 
private ViewThread mThread; 
private int calcSizeXY; 

public MenuBackgroundView(Context context, AttributeSet attrs) { 
    super(context, attrs); 
    getHolder().addCallback(this); 
    mThread = new ViewThread(this); 
    mPaint = new Paint(); 
    mPaint.setColor(Color.RED); 
    ctx = context; 
} 




public void doDraw(long elapsed, Canvas canvas) { 

    canvas.drawColor(Color.BLUE); 

    if(draw) 
    { 
     canvas.drawBitmap(blocks12x12, offX, offY, mPaint); 
    } 
    canvas.drawText("FPS: " + Math.round(1000f/elapsed) + " Elements: ", 10, 10, mPaint); 
} 

public void animate(long elapsed) 
{ 
    /* 
    //elapsed = elapsed/10; 
    offX = (offX+2); 
    if(offX >= 0) 
    { 
     offX -= 2*calcSizeXY; 
    } 

    offY = (offY+3); 
    if(offY >= 0) 
    { 
     offY -= 2*calcSizeXY; 
    } 
    //offY = (offY + (int)(elapsed/10f)) % calcSizeXY*2;// 
    * 
    */// 
} 

public void prepareBackground() 
{ 
    if(mWidth <= 1 || mHeight <= 1) 
     return; 

    Log.d("Menu", "prepareBackground"); 

    if(mHeight > mWidth) 
    { 
     calcSizeXY = mHeight/10; 
    } 
    else 
    { 
     calcSizeXY = mWidth/10;  
    } 

    offX = -2*calcSizeXY; 

    Bitmap block = BitmapFactory.decodeResource(ctx.getResources(), R.drawable.block); 
    block = Bitmap.createScaledBitmap(block, calcSizeXY, calcSizeXY, false); 




    // Group together 
    int sizeX = 12*calcSizeXY; 
    int sizeY = 12*calcSizeXY; 
    blocks12x12 = Bitmap.createBitmap(sizeX, sizeY, Bitmap.Config.ARGB_8888); 
    Canvas blocks12x12Canvas = new Canvas(blocks12x12); 

    for(int i = 0; i < 14; i+=2) 
    { 
     for(int j = 0; j < 14; j+=2) 
     { 
      blocks12x12Canvas.drawBitmap(block, (j*calcSizeXY), (i*calcSizeXY), mPaint); 
     } 
    } 

    // "Memory leak" 
    block.recycle(); 

    draw = true; 
} 




@Override 
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
    mWidth = width; 
    mHeight = height; 
    prepareBackground(); 
} 

@Override 
public void surfaceCreated(SurfaceHolder holder) { 
    prepareBackground(); 
    if (!mThread.isAlive()) { 
     mThread = new ViewThread(this); 
     mThread.setRunning(true); 
     mThread.start(); 
    } 
} 

@Override 
public void surfaceDestroyed(SurfaceHolder holder) { 
    if (mThread.isAlive()) { 
     mThread.setRunning(false); 
     freeMem(); 
    } 
} 




public void freeMem() { 
    // TODO Auto-generated method stub 
    draw = false; 
    blocks12x12.recycle(); // "Memory leak" 
} 

}

Answer 1

好吧我想出来，只需让线程睡1ms：

blocks12x12 = Bitmap.createBitmap(sizeX, sizeY, Bitmap.Config.ARGB_8888); 
    Canvas blocks12x12Canvas = new Canvas(blocks12x12); 

    for(int i = 0; i < 14; i+=2) 
    { 
     for(int j = 0; j < 14; j+=2) 
     { 
      try { 
       Thread.sleep(1); 
      } catch (InterruptedException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      blocks12x12Canvas.drawBitmap(block, (j*calcSizeXY), (i*calcSizeXY), mPaint); 
     } 
    }