Android下简单2D图像绘制

package com.vekaco.runabledraw;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.os.Handler;
import android.util.DisplayMetrics;
import android.view.View;

public class MainActivity extends Activity {
// private float initX = 0;
// private float initY=0;
private float changeX1 = 5;
private float changeX2 = 7;
private float initLeft1 = 0;
private float initRight1 = 60;
private float initLeft2 = 0;
private float initRight2 = 60;
private int windowWidth;
// private int windowHeight;
private Handler handler;
private boolean isRunning = true;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MyView myview = new MyView(this);
DisplayMetrics window = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(window);
windowWidth = window.widthPixels;
setContentView(myview);
}

private class MyView extends View implements Runnable {

public MyView(Context context) {
super(context);
// TODO Auto-generated constructor stub
handler = new Handler();
new Thread(this).start();
}

@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
Paint paint = new Paint();
paint.setColor(Color.BLUE);
paint.setStyle(Paint.Style.FILL);
canvas.drawRect(initLeft1, 10, initRight1, 100, paint);

paint.setColor(Color.RED);
canvas.drawRect(initLeft2, 110, initRight2, 200, paint);
}

@Override
public void run() {
// TODO Auto-generated method stub
while (isRunning) {
initLeft1 += changeX1;
initRight1 += changeX1;
initLeft2 += changeX2;
initRight2 += changeX2;
if ((int) initLeft1 > windowWidth) {
initRight1 = 0;
initLeft1 = -60;
}
if ((int) initLeft2 > windowWidth) {
initRight2 = 0;
initLeft2 = -60;
}
handler.post(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
invalidate();
}
});
try {
Thread.sleep(100);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
}
}
}