通过 getHolder()方法可以得到这个 SurfaceHolder对象

1、通过 getholder()方法可以得到这个 surfaceholder对象原理(来自的sdk文档)：拜访surfaceview的底层图形是通过surfaceholder接口来实现的，通过 getholder()办法可以得到这个 surfaceholder对象。你应当实现surfacecreated(surfaceholder)和 surfacedestroyed(surfaceholder)办法来知道在这个surface在窗口的显示和躲藏过程中是什么时候创建和销毁的。surfaceview可以在多线程中被拜访。注 意：一个surfaceview只在surfaceholder.callback

2、.surfacecreated() 和 surfaceholder.callback.surfacedestroyed()调用之间是可用的，其他时光是得不到它的canvas对象的 （null）。我的拜访过程：创建一个surfaceview的子类，实现surfaceholder.callback接口。得到这个surfaceview的surfaceholder对象holder。holder.addcallback(callback)，也就是实现surfaceholder.callback接口的类对象。在surfaceholder.callback.surfacecreated()调用过后holde

3、r.lockcanvas()对象就可以得到surfaceview对象对应的canvas对象canvas了。用canvas对象画图。画图结束后调用holder.unlockcanvasandpost()就把图画在窗口中了。surfaceview可以多线程拜访，在多线程中画图。import android.content.context;import android.graphics.canvas;import android.graphics.color;import android.graphics.paint;import android.util.log;import android.vi

4、ew.surfaceholder;import android.view.surfaceview;public class mysurfaceview extends surfaceview implementssurfaceholder.callback private context mcontext;private surfaceholder mholder;public touchscreenadjustersurfaceview(context context,) super(context);mcontext = context;mholder = touchscreenadjus

5、tersurfaceview.this.getholder();mholder.addcallback(touchscreenadjustersurfaceview.this);this.setfocusableintouchmode(true); / to make sure that we can get/ touch events and key events,and/ setfocusable() to make sure we/ can get key eventsoverridepublic void surfacechanged(surfaceholder holder, int

6、 format, int width,int height) / todo auto-generated method stuboverridepublic void surfacecreated(surfaceholder holder) /now you can get the canvas and draw something hereoverridepublic void surfacedestroyed(surfaceholder holder) / todo auto-generated method stubpublic void drawmyshape(pointpostion ps) mcanvas = mholder.lockcanvas();/ draw anything you likemholder.unlockcanvas