android 按键控制飞机

演示一个很好的的效果，类似雷电，但功能上差很多，现在就实现了飞机的移动功能，不过，看上去还是挺漂亮的。

首先新建一个布局main.xml文件

View Code

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:id="@+id/root"
 4     android:orientation="vertical"
 5     android:layout_width="fill_parent"
 6     android:layout_height="fill_parent"
 7     >
 8 <ImageView  
 9     android:layout_width="fill_parent" 
10     android:layout_height="fill_parent" 
11     android:src="@drawable/back"
12     android:scaleType="fitXY"
13     />
14 </LinearLayout>

第二步：建一个飞机类，这样就可以在主程序里new出飞机来了。

View Code

 1 package cn.edu.zwu.tel;
 2 
 3 import android.content.Context;
 4 import android.graphics.Bitmap;
 5 import android.graphics.BitmapFactory;
 6 import android.graphics.Canvas;
 7 import android.graphics.Paint;
 8 import android.view.View;
 9 
10 public class PlaneView extends View
11 {
12     public float currentX;
13     public float currentY;
14     Bitmap plane;
15 
16     public PlaneView(Context context)
17     {
18         super(context);
19         // TODO Auto-generated constructor stub
20 //定义飞机图片
21         plane = BitmapFactory.decodeResource(context.getResources()
22             , R.drawable.plane);
23         setFocusable(true);
24     }
25     @Override
26     public void onDraw (Canvas canvas)
27     {
28         super.onDraw(canvas);
29         //创建画笔
30         Paint p = new Paint();
31         //绘制飞机
32         canvas.drawBitmap(plane , currentX , currentY , p);    
33     }
34 }

第三，修改LayoutKeyEvent01.java文件，可以控制飞机上下移动

View Code

 1 package cn.edu.zwu.tel;
 2 
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 import android.view.Display;
 6 import android.view.KeyEvent;
 7 import android.view.View;
 8 import android.view.Window;
 9 import android.view.WindowManager;
10 import android.view.View.OnKeyListener;
11 
12 public class LayoutKeyEvent01Activity extends Activity {
13     /** Called when the activity is first created. */
14     private int speed = 12;
15 
16     @Override
17     public void onCreate(Bundle savedInstanceState)
18     {
19         super.onCreate(savedInstanceState);
20         // 去掉窗口标题
21         requestWindowFeature(Window.FEATURE_NO_TITLE);
22         // 全屏显示
23         getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
24             WindowManager.LayoutParams.FLAG_FULLSCREEN);
25         // 创建PlaneView组件
26         final PlaneView planeView = new PlaneView(this);
27         setContentView(planeView);
28         planeView.setBackgroundResource(R.drawable.back);
29         // 获取窗口管理器
30         WindowManager windowManager = getWindowManager();
31         Display display = windowManager.getDefaultDisplay();
32         // 获得屏幕宽和高
33         int screenWidth = display.getWidth();
34         int screenHeight = display.getHeight();
35         // 设置飞机的初始位置
36         planeView.currentX = screenWidth / 2;
37         planeView.currentY = screenHeight - 40;
38         // 为draw组件键盘事件绑定监听器
39         planeView.setOnKeyListener(new OnKeyListener()
40         {
41             @Override
42             public boolean onKey(View source, int keyCode, KeyEvent event)
43             {
44                 // 获取由哪个键触发的事件
45                 switch (event.getKeyCode())
46                 {
47                     // 控制飞机下移
48                     case KeyEvent.KEYCODE_DPAD_DOWN:
49                         planeView.currentY += speed;
50                         break;
51                     // 控制飞机上移
52                     case KeyEvent.KEYCODE_DPAD_UP:
53                         planeView.currentY -= speed;
54                         break;
55                     // 控制飞机左移
56                     case KeyEvent.KEYCODE_DPAD_LEFT:
57                         planeView.currentX -= speed;
58                         break;
59                     // 控制飞机右移
60                     case KeyEvent.KEYCODE_DPAD_RIGHT:
61                         planeView.currentX += speed;
62                         break;
63                 }
64                 // 通知planeView组件重绘
65                 planeView.invalidate();
66                 return true;
67             }
68         });
69     }
70 }

下面是效果图：