在自定义的SurfaceView中绘制内容

View和SurfaceView都可以用于绘制图形，但各有各的适用场合。一般情况，主动更新，不考虑UI线程的限制，双缓存加速等情况下会优先考虑SurfaceView。

下面把上篇中的MyView通过继承SurfaceView来重新编写，具体如下：

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public class MyView extends SurfaceView implements Callback, Runnable {private Paint mPaint;private SurfaceHolder mSurfaceHolder;private Thread mThread;private void initial() {mPaint = new Paint();  mPaint.setAntiAlias(true);        this.setKeepScreenOn(true);        mPaint.setColor(Color.RED);                  mThread = new Thread(this);                mSurfaceHolder = getHolder();        mSurfaceHolder.addCallback(this);        }public MyView(Context context) {super(context);initial();}public MyView(Context context, AttributeSet attrs) {super(context, attrs);initial();}private void draw() {Canvas mCanvas = null;try {mCanvas = mSurfaceHolder.lockCanvas();mCanvas.drawColor(Color.WHITE);mCanvas.drawText("绘制文字", 10, 20, mPaint);mCanvas.drawCircle(35, 50, 20, mPaint);} catch (Exception e) {e.printStackTrace();} finally {if (mCanvas != null) {mSurfaceHolder.unlockCanvasAndPost(mCanvas);}}}@Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height) {}@Overridepublic void surfaceCreated(SurfaceHolder holder) {mThread.start();}@Overridepublic void surfaceDestroyed(SurfaceHolder holder) {}@Overridepublic void run() {draw();}}

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获取SurfaceHolder：mSurfaceHolder = getHolder();为SurfaceHolder添加CallBack：mSurfaceHolder.addCallback(this);创建绘制线程：mThread = new Thread(this);绘制函数：draw();自定义的函数名称，如果你喜欢，你可以在遵守规则的前提下随意命名；当SurfaceView被创建时，启动绘制线程：mThread.start();从SurfaceHolder获得Canvas对象：mCanvas = mSurfaceHolder.lockCanvas();

调用方式和以前一样，这也仅仅是一个View，只不过是继承SurfaceView而已！

效果如图：

希望对你有所帮助！：）

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