SurfaceView的經典寫法

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;

/**
 * 繼承SurfaceView
 * 實現SurfaceHolder.Callback,給SurfaceHolder用的
 * 創建SurfaceHolder,並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;
	//線程
	private Thread t;
	private boolean flag;
	//數據
	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 {
			//當SurfaceView不可編輯或尚未創建,會返回null
			c = sfh.lockCanvas();
			if(c != null) {
				c.drawColor(Color.GREEN);//刷屏
				c.drawText("me", xx, yy, p);//畫
			}
		} catch(Exception e) {
			
		} finally {
			if(c != null) {
				sfh.unlockCanvasAndPost(c);
			}
		}
	}
	
	//遊戲邏輯
	public void logic() {
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		screenW = this.getWidth();
		screenH = this.getHeight();
		//線程的初始化和啓動都寫在create裏面
		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) {
			//刷屏時間保持一致
			//一般會在10~20幀左右
			//每秒20幀:1000ms/20=50ms每幀
			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的生命週期:



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