SurfaceView的经典写法

package com.example.test;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;

/**
 * 继承SurfaceView
 * 实现SurfaceHolder.Callback。给SurfaceHolder用的
 * 创建SurfaceHolder。并addCallback，SurfaceView的一切都有SurfaceHolder控制
 */
public class MySurfaceView extends SurfaceView
		implements Callback, Runnable {
	//SurfaceView基本
	private SurfaceHolder sfh;//操控SurfaceView
	private Paint p;
	private Canvas c;
	//线程
	private Thread t;
	private boolean flag;
	//数据
	private int screenW, screenH;
	private int xx = 100, yy = 100;

	public MySurfaceView(Context context) {
		super(context);
		sfh = this.getHolder();
		sfh.addCallback(this);
		p = new Paint();
		p.setColor(Color.RED);
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		xx = (int) event.getX();
		yy = (int) event.getY();
		return true;
	}

	public void myDraw() {
		try {
			//当SurfaceView不可编辑或尚未创建。会返回null
			c = sfh.lockCanvas();
			if(c != null) {
				c.drawColor(Color.GREEN);//刷屏
				c.drawText("me", xx, yy, p);//画
			}
		} catch(Exception e) {

		} finally {
			if(c != null) {
				sfh.unlockCanvasAndPost(c);
			}
		}
	}

	//游戏逻辑
	public void logic() {
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		screenW = this.getWidth();
		screenH = this.getHeight();
		//线程的初始化和启动都写在create里面
		flag = true;
		t = new Thread(this);
		t.start();
	}

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

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

	@Override
	public void run() {
		while (flag) {
			//刷屏时间保持一致
			//通常会在10~20帧左右
			//每秒20帧：1000ms/20=50ms每帧
			long start = System.currentTimeMillis();
			myDraw();
			logic();
			long end = System.currentTimeMillis();
			try {
				if(end - start < 50) {
					Thread.sleep(50 - (end-start));
				}
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
	}
}

SurfaceView的生命周期：