android游戏开发学习笔记三（学习书籍 Android游戏编程之从零开始）

/**
* 画笔
*
* @author 岳振华
*
*/
@SuppressWarnings("unused")
public class PaintSrufaceView extends SurfaceView implements Callback, Runnable {
private SurfaceHolder sfh;
private Thread thread;
private int surfaceW, surfaceH;
private Canvas canvas;
private boolean flag;//surfaceView是否销毁的标志位

public PaintSrufaceView(Context context) {
super(context);


/********** 画图所必需 *********************/
sfh = this.getHolder();// 获得surfaceHolder对象
sfh.addCallback(this);


thread = new Thread(this);
this.setKeepScreenOn(true);// 保持屏幕常亮
this.setFocusable(true);
/********************************************/





}


/**
* 开始动画
*/
@Override
public void startAnimation(Animation animation) {
super.startAnimation(animation);
}


/**************************** callback的几个方法 ********************/


/**
* 当Surface第一次创建后会立即调用该函数 一般情况下都是在另外的线程来绘制界面，所以不要在这个函数中绘制Surface
*/
@Override
public void surfaceCreated(SurfaceHolder holder) {
surfaceW = this.getWidth();
surfaceH = this.getHeight();
thread = new Thread(this);
flag=true;
thread.start();// 开启线程


}


/**
* 当Surface的状态（大小和格式）发生变化的时候会调用 该函数 在surfaceCreated调用后该函数至少会被调用一次
*/
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {


}


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


/**************************** callback的几个方法 ********************/


/**
* 绘图方法
*/
private void draw() {
try {
// 获得canvas实例
canvas = sfh.lockCanvas();
if (canvas != null) {
// 利用填充画布,刷屏
canvas.drawColor(Color.BLACK);
/****************画圆*****************/
//消除 锯齿前
Paint paint1 =new Paint();
paint1.setColor(Color.YELLOW);
canvas.drawCircle(50, 50, 20, paint1);
//消除 锯齿后
paint1.setAntiAlias(true);
canvas.drawCircle(100, 50, 20, paint1);
/***************************************/
/************写文本********************/
Paint paint3=new Paint();
paint3.setColor(Color.RED);
canvas.drawText("无透明", 100, 200, paint3);
//半透明
Paint paint2=new Paint();
paint2.setColor(Color.RED);
paint2.setAlpha(0x77);
canvas.drawText("半透明", 100, 220, paint2);
/**************************************/
/*************锚点**********************/
//-----设置绘制文本的锚点
canvas.drawText("锚点", 20, 90, new Paint());
Paint paint4 = new Paint();
paint4.setColor(Color.GREEN);
//设置以文本的中心点绘制
paint4.setTextAlign(Paint.Align.CENTER);
canvas.drawText("锚点", 20, 105, paint4);


}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (null != canvas) {
sfh.unlockCanvasAndPost(canvas);// 提交画布
}
}
}


@SuppressWarnings("static-access")
@Override
public void run() {
while(flag)
{
// 绘图
draw();
try {
thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}



}
}