Android基于ImageSwitcher实现图片切换功能

左右切换图片控件大家都用viewpager, viewfipper比较多吧，我之前也用viewpager实现了，使用viewpager实现左右循环滑动图片，有兴趣的可以去看下，今天介绍的是基于imageswitcher实现的左右切换图片，先上截图吧

好了，接下来来看代码吧，第一张图是一个gridview，点击item跳转到第二个界面，第一个界面可以忽略，主要是讲解imageswitcher的左右却换图片，先看布局文件

<?xml version="1.0" encoding="utf-8"?> 
<framelayout xmlns:android="http://schemas.android.com/apk/res/android" 
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent" > 
  <imageswitcher 
    android:id="@+id/imageswitcher1" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"> 
  </imageswitcher> 
   
  <relativelayout   
    android:layout_width="fill_parent"   
    android:layout_height="wrap_content"   
    android:orientation="vertical" >   
    <linearlayout   
      android:id="@+id/viewgroup"   
      android:layout_width="fill_parent"   
      android:layout_height="wrap_content"   
      android:layout_alignparentbottom="true"   
      android:layout_marginbottom="30dp"   
      android:gravity="center_horizontal"   
      android:orientation="horizontal" >   
    </linearlayout>   
  </relativelayout> 
</framelayout> 

然后就是activity代码啦，总体来说比较简单，代码我添加了注释

package com.example.photoalbum; 
 
import android.app.activity; 
import android.os.bundle; 
import android.view.motionevent; 
import android.view.view; 
import android.view.view.ontouchlistener; 
import android.view.viewgroup; 
import android.view.animation.animationutils; 
import android.widget.imageswitcher; 
import android.widget.imageview; 
import android.widget.linearlayout; 
import android.widget.relativelayout.layoutparams; 
import android.widget.toast; 
import android.widget.viewswitcher.viewfactory; 
 
public class showphotoactivity extends activity implements viewfactory, ontouchlistener{ 
  /** 
   * imagaswitcher 的引用 
   */ 
  private imageswitcher mimageswitcher; 
  /** 
   * 图片id数组 
   */ 
  private int[] imgids; 
  /** 
   * 当前选中的图片id序号 
   */ 
  private int currentposition; 
  /** 
   * 按下点的x坐标 
   */ 
  private float downx; 
  /** 
   * 装载点点的容器 
   */ 
  private linearlayout linearlayout; 
  /** 
   * 点点数组 
   */ 
  private imageview[] tips; 
  
  @override 
  protected void oncreate(bundle savedinstancestate) { 
    super.oncreate(savedinstancestate); 
    setcontentview(r.layout.show_photo); 
     
    imgids = new int[]{r.drawable.item01,r.drawable.item02,r.drawable.item03,r.drawable.item04, 
        r.drawable.item05, r.drawable.item06, r.drawable.item07, r.drawable.item08,r.drawable.item09, 
        r.drawable.item10, r.drawable.item11, r.drawable.item12}; 
    //实例化imageswitcher 
    mimageswitcher = (imageswitcher) findviewbyid(r.id.imageswitcher1); 
    //设置factory 
    mimageswitcher.setfactory(this); 
    //设置ontouchlistener，我们通过touch事件来切换图片 
    mimageswitcher.setontouchlistener(this); 
     
    linearlayout = (linearlayout) findviewbyid(r.id.viewgroup); 
     
    tips = new imageview[imgids.length]; 
    for(int i=0; i<imgids.length; i++){ 
      imageview mimageview = new imageview(this); 
      tips[i] = mimageview; 
      linearlayout.layoutparams layoutparams = new linearlayout.layoutparams(new viewgroup.layoutparams(layoutparams.wrap_content,   
          layoutparams.wrap_content));  
      layoutparams.rightmargin = 3; 
      layoutparams.leftmargin = 3; 
       
      mimageview.setbackgroundresource(r.drawable.page_indicator_unfocused); 
      linearlayout.addview(mimageview, layoutparams); 
    } 
     
    //这个我是从上一个界面传过来的，上一个界面是一个gridview 
    currentposition = getintent().getintextra("position", 0); 
    mimageswitcher.setimageresource(imgids[currentposition]); 
     
    setimagebackground(currentposition); 
     
  } 
   
   /** 
   * 设置选中的tip的背景 
   * @param selectitems 
   */  
  private void setimagebackground(int selectitems){  
    for(int i=0; i<tips.length; i++){  
      if(i == selectitems){  
        tips[i].setbackgroundresource(r.drawable.page_indicator_focused);  
      }else{  
        tips[i].setbackgroundresource(r.drawable.page_indicator_unfocused);  
      }  
    }  
  }  
 
  @override 
  public view makeview() { 
    final imageview i = new imageview(this); 
    i.setbackgroundcolor(0xff000000); 
    i.setscaletype(imageview.scaletype.center_crop); 
    i.setlayoutparams(new imageswitcher.layoutparams(layoutparams.fill_parent, layoutparams.fill_parent)); 
    return i ; 
  } 
 
  @override 
  public boolean ontouch(view v, motionevent event) { 
    switch (event.getaction()) { 
    case motionevent.action_down:{ 
      //手指按下的x坐标 
      downx = event.getx(); 
      break; 
    } 
    case motionevent.action_up:{ 
      float lastx = event.getx(); 
      //抬起的时候的x坐标大于按下的时候就显示上一张图片 
      if(lastx > downx){ 
        if(currentposition > 0){ 
          //设置动画，这里的动画比较简单，不明白的去网上看看相关内容 
          mimageswitcher.setinanimation(animationutils.loadanimation(getapplication(), r.anim.left_in)); 
          mimageswitcher.setoutanimation(animationutils.loadanimation(getapplication(), r.anim.right_out)); 
          currentposition --; 
          mimageswitcher.setimageresource(imgids[currentposition % imgids.length]); 
          setimagebackground(currentposition); 
        }else{ 
          toast.maketext(getapplication(), "已经是第一张", toast.length_short).show(); 
        } 
      }  
       
      if(lastx < downx){ 
        if(currentposition < imgids.length - 1){ 
          mimageswitcher.setinanimation(animationutils.loadanimation(getapplication(), r.anim.right_in)); 
          mimageswitcher.setoutanimation(animationutils.loadanimation(getapplication(), r.anim.lift_out)); 
          currentposition ++ ; 
          mimageswitcher.setimageresource(imgids[currentposition]); 
          setimagebackground(currentposition); 
        }else{ 
          toast.maketext(getapplication(), "到了最后一张", toast.length_short).show(); 
        } 
      } 
      } 
       
      break; 
    } 
 
    return true; 
  } 
 
} 

上面切换图片主要用到的就是动画了，用的是translate移动动画，这里我就不介绍了，接下来我吧动画代码贴出来，在res新建一个anim的目录，如下图

左边进入的动画，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"/> 
</set> 

左边出去的动画,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"/> 
</set> 

右边进入的动画，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"/> 
</set> 

右边出去的动画,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"/> 
</set> 

好了，介绍完了，代码写的不是很好，写的不好的地方希望大家谅解，小编一定更加努力。