Android中使用ViewFlipper进行手势切换实例

本文实例讲述了android中使用viewflipper进行手势切换的方法，分享给大家供大家参考。具体实现步骤如下：

首先在layout的xml文件中定义一个viewflipper：

<?xml version="1.0" encoding="utf-8"?> 
<viewflipper xmlns:android="http://schemas.android.com/apk/res/android" 
        android:id="@+id/viewflipper" 
        android:layout_width="fill_parent"  
        android:layout_height="fill_parent" 
        > 
         
    <linearlayout 
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent" 
        > 
         
        <textview 
            android:layout_width="fill_parent" 
            android:layout_height="fill_parent" 
            android:background="#ff0000" 
            /> 
             
    </linearlayout> 
     
    <linearlayout 
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent" 
        > 
         
        <textview 
            android:layout_width="fill_parent" 
            android:layout_height="fill_parent" 
            android:background="#00ff00" 
            /> 
             
    </linearlayout> 
     
</viewflipper>

声明一个新的gesturedetector，重写它的onfling()函数，在这个函数里面判断手势，这里为横向的拖动：

public class mygesturedetector extends simpleongesturelistener 
{ 
    private static final int swipe_min_distance = 120; 
    private static final int swipe_max_off_path = 250; 
    private static final int swipe_threshold_velocity = 200; 
     
    @override 
    public boolean onfling(motionevent e1, motionevent e2,  
                           float velocityx, float velocityy) 
    { 
        try 
        { 
               if (math.abs(e1.gety() - e2.gety()) > swipe_max_off_path) 
               { 
                   return false; 
               } 
               if(e1.getx() - e2.getx() > swipe_min_distance &&  
                  math.abs(velocityx) > swipe_threshold_velocity) 
               { 
                viewflipper.setinanimation(slideleftin); 
                   viewflipper.setoutanimation(slideleftout); 
                viewflipper.shownext(); 
               } 
               else  
                if (e2.getx() - e1.getx() > swipe_min_distance &&  
                    math.abs(velocityx) > swipe_threshold_velocity) 
                { 
                    viewflipper.setinanimation(sliderightin); 
                    viewflipper.setoutanimation(sliderightout); 
                    viewflipper.showprevious(); 
                } 
           } 
        catch (exception e) 
        { 
             
           } 
           return false; 
    } 
}

注意在activity中重写ontouchevent()函数：

private viewflipper viewflipper; 
 
private animation slideleftin; 
private animation slideleftout; 
private animation sliderightin; 
private animation sliderightout; 
 
private gesturedetector gesturedetector; 
@override 
public void oncreate(bundle savedinstancestate) 
{ 
    super.oncreate(savedinstancestate); 
    setcontentview(r.layout.main); 
     
    viewflipper = (viewflipper)findviewbyid(r.id.viewflipper); 
       slideleftin = animationutils.loadanimation(this, r.anim.slide_left_in); 
       slideleftout = animationutils.loadanimation(this, r.anim.slide_left_out); 
       sliderightin = animationutils.loadanimation(this, r.anim.slide_right_in); 
       sliderightout = animationutils.loadanimation(this, r.anim.slide_right_out); 
        
       gesturedetector = new gesturedetector(new mygesturedetector()); 
        
       new view.ontouchlistener() 
       { 
           public boolean ontouch(view v, motionevent event) 
           { 
               if (gesturedetector.ontouchevent(event)) 
               { 
                   return true; 
               } 
               return false; 
           } 
       }; 
} 
 
@override 
public boolean ontouchevent(motionevent event) 
{ 
    if (gesturedetector.ontouchevent(event)) 
    { 
        return true; 
    } 
    else 
    { 
        return false; 
    } 
}

最后，在res文件夹下新建一个anim文件夹，用来存放view之间切换的动画文件：

1.slide_left_in.xml

<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="http://schemas.android.com/apk/res/android"> 
    <translate 
        android:fromxdelta="100%p"  
        android:toxdelta="0"  
        android:duration="500" 
        /> 
    <alpha 
        android:fromalpha="0.0"  
        android:toalpha="1.0" 
        android:duration="500" 
        /> 
</set>

2.slide_left_out.xml

<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="http://schemas.android.com/apk/res/android"> 
    <translate 
        android:fromxdelta="0"  
        android:toxdelta="-100%p"  
        android:duration="500" 
        /> 
    <alpha 
        android:fromalpha="1.0"  
        android:toalpha="0.0"  
        android:duration="500" 
        /> 
</set>

3.slide_right_in.xml

<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="http://schemas.android.com/apk/res/android"> 
    <translate  
        android:fromxdelta="-100%p"  
        android:toxdelta="0"  
        android:duration="500" 
        /> 
    <alpha 
        android:fromalpha="0.0"  
        android:toalpha="1.0" 
        android:duration="500" 
        /> 
</set>

4.slide_right_out.xml

<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="http://schemas.android.com/apk/res/android"> 
    <translate  
        android:fromxdelta="0"  
        android:toxdelta="100%p"  
        android:duration="500" 
        /> 
    <alpha 
        android:fromalpha="1.0"  
        android:toalpha="0.0" 
        android:duration="500" 
        /> 
</set>

希望本文所述对大家的android程序设计有所帮助