SurfaceView和View的区别

SurfaceView是一个专门用于做频繁绘制的View子类，它的绘制操作是在子线程中执行，所以频繁绘制不会阻塞线程，使用它去做一些需要频繁绘制和长时间绘制效果会高很多。而如果这种操作放入到View中去做的话就不合适了，首先View的刷新UI操作都是需要在UI线程中，也就是我们的主线程中。如果去执行一些需要长时间绘制，就会造成UI阻塞造成无法响应其他时间

使用过程
surfaceCreated
创建时调用，如果View隐藏或者activity onResume方法也会重新调用。

surfaceChanged
surfaceCreated 后调用

surfaceDestroyed
view隐藏或者销毁时调用

SurfaceHolder mHolder = getHolder();
获取一个holder获取canvas和提交canvas

Canvas canvas = mHolder.lockCanvas();
获取canvas做绘制操作

mHolder.unlockCanvasAndPost(canvas);
提交绘制操作

public class DrawingBoardView extends SurfaceView implements SurfaceHolder.Callback, Runnable {
   
    public DrawingBoardView(Context context) {
        this(context, null);
    }


    public DrawingBoardView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }


    public DrawingBoardView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    private void initData() {
        mHolder = getHolder();
        getBackground().setAlpha(127);
        setZOrderMediaOverlay(true);
        setZOrderOnTop(true);
        mHolder.setFormat(PixelFormat.TRANSLUCENT);
        mHolder.unlockCanvasAndPost(canvas);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {

    }


    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    }


    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mIsRuning = false;
    }


    @Override
    public void run() {
    }

    
    private void drawPattern(int x, int y) {
        //绘制过程
        Canvas canvas = mHolder.lockCanvas();
        Canvas newCanvas = new Canvas(mDrawBitmap);
        canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
        canvas.drawBitmap(mDrawBitmap, 0, 0, mPaint);
        mHolder.unlockCanvasAndPost(canvas);
    }


}

参考