Android实战简易教程<十二>（ViewFlipper实现幻灯效果）

直接看代码

1.MainActivity.java:

[java] view plaincopy

1. package org.yayun.demo;  
2.   
3. import android.app.Activity;  
4. import android.os.Bundle;  
5. import android.view.GestureDetector;  
6. import android.view.MotionEvent;  
7. import android.view.ViewGroup.LayoutParams;  
8. import android.view.animation.Animation;  
9. import android.view.animation.AnimationUtils;  
10. import android.widget.ImageView;  
11. import android.widget.ViewFlipper;  
12.   
13. public class MainActivity extends Activity implements  
14.         android.view.GestureDetector.OnGestureListener {  
15.   
16.     private int[] imgs = { R.drawable.img1, R.drawable.img2, R.drawable.img3 };  
17.     private GestureDetector gestureDetector;  
18.     private ViewFlipper viewFlipper;  
19.     private Activity mActivity;  
20.   
21.     @Override  
22.     protected void onCreate(Bundle savedInstanceState) {  
23.         super.onCreate(savedInstanceState);  
24.         setContentView(R.layout.activity_main);  
25.         mActivity = this;  
26.         viewFlipper = (ViewFlipper) findViewById(R.id.viewflipper);  
27.   
28.         gestureDetector = new GestureDetector(this);//手势监听  
29.   
30.         for (int i = 0; i < imgs.length; i++) { // 添加图片源  
31.             ImageView iv = new ImageView(this);  
32.             iv.setImageResource(imgs[i]);  
33.             iv.setScaleType(ImageView.ScaleType.FIT_XY);  
34.             viewFlipper.addView(iv, new LayoutParams(LayoutParams.FILL_PARENT,  
35.                     LayoutParams.FILL_PARENT));  
36.         }  
37.   
38.         viewFlipper.setAutoStart(true); // 设置自动播放功能（点击事件，前自动播放）  
39.         viewFlipper.setFlipInterval(3000);//间隔3秒  
40.         if (viewFlipper.isAutoStart() && !viewFlipper.isFlipping()) {  
41.             viewFlipper.startFlipping();  
42.         }  
43.     }  
44.   
45.     @Override  
46.     public boolean onTouchEvent(MotionEvent event) {  
47.         // TODO Auto-generated method stub  
48.         viewFlipper.stopFlipping(); // 点击事件后，停止自动播放  
49.         viewFlipper.setAutoStart(false);  
50.         return gestureDetector.onTouchEvent(event); // 注册手势事件  
51.     }  
52.   
53.     public boolean onDown(MotionEvent arg0) {  
54.         // TODO Auto-generated method stub  
55.         return false;  
56.     }  
57.   
58.     public boolean onFling(MotionEvent e1, MotionEvent e2, float arg2,  
59.             float arg3) {  
60.         if (e2.getX() - e1.getX() > 120) { // 从左向右滑动（左进右出）  
61.             Animation rInAnim = AnimationUtils.loadAnimation(mActivity,  
62.                 R.layout.push_right_in); // 向右滑动左侧进入的渐变效果（alpha 0.1 -> 1.0）  
63.             Animation rOutAnim = AnimationUtils.loadAnimation(mActivity,  
64.                     R.layout.push_right_out); // 向右滑动右侧滑出的渐变效果（alpha 1.0 -> 0.1）  
65.   
66.             viewFlipper.setInAnimation(rInAnim);  
67.             viewFlipper.setOutAnimation(rOutAnim);  
68.             viewFlipper.showPrevious();  
69.             return true;  
70.         } else if (e2.getX() - e1.getX() < -120) { // 从右向左滑动（右进左出）  
71.             Animation lInAnim = AnimationUtils.loadAnimation(mActivity,  
72.                     R.layout.push_left_in); // 向左滑动左侧进入的渐变效果（alpha 0.1 -> 1.0）  
73.             Animation lOutAnim = AnimationUtils.loadAnimation(mActivity,  
74.                     R.layout.push_left_out); // 向左滑动右侧滑出的渐变效果（alpha 1.0 -> 0.1）  
75.   
76.             viewFlipper.setInAnimation(lInAnim);  
77.             viewFlipper.setOutAnimation(lOutAnim);  
78.             viewFlipper.showNext();  
79.             return true;  
80.         }  
81.         return true;  
82.     }  
83.   
84.     public void onLongPress(MotionEvent arg0) {  
85.         // TODO Auto-generated method stub  
86.   
87.     }  
88.   
89.     public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,  
90.             float arg3) {  
91.         // TODO Auto-generated method stub  
92.         return false;  
93.     }  
94.   
95.     public void onShowPress(MotionEvent arg0) {  
96.         // TODO Auto-generated method stub  
97.   
98.     }  
99.   
100.     public boolean onSingleTapUp(MotionEvent arg0) {  
101.         // TODO Auto-generated method stub  
102.         return false;  
103.     }  
104.   
105. }  

2.active_main.xml:

[html] view plaincopy

1. <?xml version="1.0" encoding="utf-8"?>    
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    
3.     android:layout_width="fill_parent"    
4.     android:layout_height="fill_parent"    
5.     android:orientation="vertical" >    
6.     
7.     <ViewFlipper    
8.         android:id="@+id/viewflipper"    
9.         android:layout_width="fill_parent"    
10.         android:layout_height="fill_parent"/>    
11.     
12. </LinearLayout>    

下面看四个动画文件，很简单.

1.push_left_in.xml

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1. <?xml version="1.0" encoding="utf-8"?>      
2. <set xmlns:android="http://schemas.android.com/apk/res/android" >      
3.     <translate      
4.         android:duration="1500"      
5.         android:fromXDelta="100%p"      
6.         android:toXDelta="0" />  <!-- 位移   -->  
7.       
8.     <alpha      
9.         android:duration="1500"      
10.         android:fromAlpha="0.1"      
11.         android:toAlpha="1.0" /> <!-- 渐变    -->  
12. </set>   

2.push_left_out.xml

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1. <?xml version="1.0" encoding="utf-8"?>      
2. <set xmlns:android="http://schemas.android.com/apk/res/android" >      
3.     <translate      
4.         android:duration="1500"      
5.         android:fromXDelta="0"      
6.         android:toXDelta="-100%p" />      
7.       
8.     <alpha      
9.         android:duration="1500"      
10.         android:fromAlpha="1.0"      
11.         android:toAlpha="0.1" />      
12. </set>     

3.push_right_in.xml

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1. <?xml version="1.0" encoding="utf-8"?>      
2. <set xmlns:android="http://schemas.android.com/apk/res/android" >      
3.     <translate      
4.         android:duration="1500"      
5.         android:fromXDelta="-100%p"      
6.         android:toXDelta="0" />      
7.       
8.     <alpha      
9.         android:duration="1500"      
10.         android:fromAlpha="0.1"      
11.         android:toAlpha="1.0" />      
12. </set>    

4.push_right_out.xml

[html] view plaincopy

1. <?xml version="1.0" encoding="utf-8"?>      
2. <set xmlns:android="http://schemas.android.com/apk/res/android" >      
3.     <translate      
4.         android:duration="1500"      
5.         android:fromXDelta="0"      
6.         android:toXDelta="100%p" />      
7.       
8.     <alpha      
9.         android:duration="1500"      
10.         android:fromAlpha="1.0"      
11.         android:toAlpha="0.1" />      
12. </set>  

运行实例如下：