上面的飞机移动背景是用定时器不断挖取源位图的块，从而形成背景移动的假象
控制图片背景不断下移，就会感觉飞机在不断的飞行
本程序有两个位图，一个背景图，高度远超过屏幕的高度，然后是一张飞机的位图
package WangLi.Graphics.MoveBack;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
public class MoveBack extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(new MyView(this));
}
class MyView extends View
{
//记录背景位图的实际高度
final int BACK_HEIGHT = 1700;
//背景图片
private Bitmap back;
private Bitmap plane;
//背景图片的开始位置
final int WIDTH = 371;
final int HEIGHT = 440;
private int startY = BACK_HEIGHT - HEIGHT;
public MyView(Context context)
{
super(context);
// TODO Auto-generated constructor stub
back = BitmapFactory.decodeResource(context.getResources()
, R.drawable.back_img);
plane = BitmapFactory.decodeResource(context.getResources()
, R.drawable.plane);
final Handler handler = new Handler()
{
public void handleMessage(Message msg)
{
if (msg.what == 0x123)
{
//重新开始移动
if (startY <= 0)
{
startY = BACK_HEIGHT - HEIGHT;
}
else
{
startY -= 3;
}
}
invalidate();
}
};
new Timer().schedule(new TimerTask()
{
@Override
public void run()
{
handler.sendEmptyMessage(0x123);
}}, 0 , 10);
}
@Override
public void onDraw(Canvas canvas)
{
// 根据原始位图和Matrix创建新图片
Bitmap bitmap2 = Bitmap.createBitmap(back, 0, startY
, WIDTH , HEIGHT);
// 绘制新位图
canvas.drawBitmap(bitmap2, 0 , 0, null);
// 绘制飞机
canvas.drawBitmap(plane, 160 , 380, null);
}
}
}【初学Android,图形图像之游戏画面中飞行的飞机(三十)】
