先看看效果：
SurfaceView和View的明显不同在于Surface不需要通过线程来更新视图，但在绘制之前必须使用lockCanvas方法锁定画布，并得 到画布，然后绘制，完成后用unlockCanvasAndPost方法解锁画布。SurfaceView类的事件处理和View一样。
绘制界面的类：
package com.yarin.android.Examples_05_02;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class GameSurfaceView extends SurfaceView
implements SurfaceHolder.Callback,Runnable
{
//控制循环
boolean mbLoop = false;
//定义SurfaceHolder对象
SurfaceHolder mSurfaceHolder = null;
int miCount = 0;
int y = 50;
public GameSurfaceView(Context context)
{
super(context);
// 实例化SurfaceHolder
mSurfaceHolder = this.getHolder();
// 添加回调
mSurfaceHolder.addCallback(this);
this.setFocusable(true);
mbLoop = true;
}
// 在surface的大小发生改变时激发
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
{
}
// 在surface创建时激发
public void surfaceCreated(SurfaceHolder holder)
{
//开启绘图线程
new Thread(this).start();
}
// 在surface销毁时激发
public void surfaceDestroyed(SurfaceHolder holder)
{
// 停止循环
mbLoop = false;
}
// 绘图循环
public void run()
{
while (mbLoop)
{
try
{
Thread.sleep(200);
}
catch (Exception e)
{
}
synchronized( mSurfaceHolder )
{
Draw();
}
}
}
// 绘图方法
public void Draw()
{
//锁定画布，得到canvas
Canvas canvas= mSurfaceHolder.lockCanvas();
if (mSurfaceHolder==null || canvas == null )
{
return;
}
if (miCount < 100)
{
miCount++;
}
else
{
miCount = 0;
}
// 绘图
Paint mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setColor(Color.BLACK);
//绘制矩形--清屏作用
canvas.drawRect(0, 0, 320, 480, mPaint);
switch (miCount % 4)
{
case 0:
mPaint.setColor(Color.BLUE);
break;
case 1:
mPaint.setColor(Color.GREEN);
break;
case 2:
mPaint.setColor(Color.RED);
break;
case 3:
mPaint.setColor(Color.YELLOW);
break;
default:
mPaint.setColor(Color.WHITE);
break;
}
canvas.drawCircle((320 - 25) / 2, y, 50, mPaint);
// 绘制后解锁，绘制后必须解锁才能显示
mSurfaceHolder.unlockCanvasAndPost(canvas);
}
}
事件处理：
package com.yarin.android.TestOnSurface;
import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.MotionEvent;
public class TestOnSurface extends Activity
{
GameSurfaceView mGameSurfaceView;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mGameSurfaceView = new GameSurfaceView(this);
//设置显示GameSurfaceView视图
setContentView(mGameSurfaceView);
}
//触笔事件
public boolean onTouchEvent(MotionEvent event)
{
return true;
}
//按键按下事件
public boolean onKeyDown(int keyCode, KeyEvent event)
{
return true;
}
//按键弹起事件
public boolean onKeyUp(int keyCode, KeyEvent event)
{
switch (keyCode)
{
//上方向键
case KeyEvent.KEYCODE_DPAD_UP:
mGameSurfaceView.y-=3;
break;
//下方向键
case KeyEvent.KEYCODE_DPAD_DOWN:
mGameSurfaceView.y+=3;
break;
}
return false;
}
public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)
{
return true;
}
}
