android surfaceViewd的使用——简单画图

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public class SurfaceDraw    extends Activity{   

     private SurfaceView      sf;     

     private SurfaceHolder  sfh;   //surfaceView的 控制器 

    @Override 

    protected void onCreate(Bundle savedInstanceState) { 

        //   TODO Auto-generated method stub 

        super.onCreate(savedInstanceState);   

        setContentView(R.layout.activity_draw);   

        sf   = (SurfaceView) this.findViewById(R.id.SurfaceView01); 

        //得到控制器 

        sfh   = sf.getHolder(); 

        //对 surfaceView 进行操作 

        sfh.addCallback(new DoThings());// 自动运行surfaceCreated以及surfaceChanged 

    } 

    private class DoThings implements SurfaceHolder.Callback{ 

        @Override 

        public void surfaceChanged(SurfaceHolder holder, int format, int width, 

                int height) { 

            //在surface的大小发生改变时激发 

            System.out.println("surfaceChanged");   

        }   

        @Override 

        public void surfaceCreated(SurfaceHolder holder){ 

            new Thread(){ 

                public void run() { 

                    while(true){   

                        //1.这里就是核心了， 得到画布 ，然后在你的画布上画出要显示的内容   

                        Canvas   c = sfh.lockCanvas(new Rect(0, 0, 200, 200)); 

                        //2.开画 

                        Paint    p =new Paint();   

                        p.setColor(Color.rgb(   (int)(Math.random() * 255),  

                                (int)(Math.random()   * 255) ,  (int)(Math.random() * 255))); 

                        Rect   aa  =  new Rect( (int)(Math.random() * 100) , 

                                (int)(Math.random()   * 100)  

                                ,(int)(Math.random()   * 500)  

                                ,(int)(Math.random()   * 500) ); 

                        c.drawRect(aa,   p); 

                        //3.   解锁画布     更新提交屏幕显示内容 

                        sfh.unlockCanvasAndPost(c);   

                        try { 

                            Thread.sleep(1000);   

                        }   catch (Exception   e) { 

                        }   

                    }   

                };   

            }.start();   

        }   

        @Override 

        public void surfaceDestroyed(SurfaceHolder holder) { 

               //销毁时激发，一般在这里将画图的线程停止、释放。 

            System.out.println("surfaceDestroyed==");      

        }      

    } 

}