游戏开发第一节——画一个简单的图形

我们先来画一个圆吧，了解一下surfaceView的一般框架。

CircleActivity.java代码

package yy.circle;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;

public class CircleActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(new Circle(this));
}

}

Circle.java代码

package yy.circle;

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

public class Circle extends SurfaceView implements Callback,Runnable {
private SurfaceHolder sfh;
private Paint paint;
private Thread thread;
private boolean flag;
private Canvas canvas;
private int screenW,screenH;
private PaintFlagsDrawFilter pfd=new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG|Paint.FILTER_BITMAP_FLAG);
public Circle(Context context){
super(context);
sfh=this.getHolder();
sfh.addCallback(this);
paint=new Paint();
paint.setColor(Color.WHITE);
System.out.print("1");
setFocusable(true);
}
public void surfaceCreated(SurfaceHolder holder){
screenW=this.getWidth();
screenH=this.getHeight();
flag=true;
thread=new Thread(this);
thread.start();
}
public void myDraw(){
try{
canvas=sfh.lockCanvas();
if(canvas!=null){
canvas.setDrawFilter(pfd);
canvas.drawColor(Color.BLACK);
System.out.print("2");
canvas.drawCircle(50, 50, 50, paint);
System.out.print("3");
}
}catch(Exception e){}
finally{
if(canvas!=null){
sfh.unlockCanvasAndPost(canvas);
}
}
}
public boolean onTouchEvent(MotionEvent event){
return true;
}
public boolean onKeyDown(int keyCode,KeyEvent event){
return super.onKeyDown(keyCode, event);
}
public void logic(){}
public void run(){
while(flag){
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();
}
}
}
public void surfaceChanged(SurfaceHolder holder,int format,int width,int height){}
public void surfaceDestroyed(SurfaceHolder holder){
flag=false;
}

}