继上一篇介绍了如何使用Gallery控件之后，本文就来讲一下Gallery 与ImageSwitcher的结合使用。本文所述实例代码将实现一个简单的浏览图片的功能。

先贴出程序运行截图如下：

除了Gallery可以拖拉切换图片，我在ImageSwitcher控件加入了setOnTouchListener事件实现，使得ImageSwitcher也可以在拖拉中切换图片。本例子依然使用JAVA的反射机制来自动读取资源中的图片。

main.xml的源码如下:

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   android:layout_width="match_parent"   android:layout_height="match_parent">     <ImageSwitcher android:id="@+id/switcher"    android:layout_width="match_parent" android:layout_height="match_parent"/>    <Gallery android:id="@+id/gallery"    android:background="#55000000"    android:layout_width="match_parent"    android:layout_alignParentBottom="true"    android:layout_alignParentLeft="true"        android:gravity="center_vertical"    android:spacing="16dp" android:layout_height="100dp"/></RelativeLayout>

Java程序的源码如下:

package com.testImageView;import java.lang.reflect.Field;import java.util.ArrayList;import android.app.Activity;import android.content.Context;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.AdapterView;import android.widget.BaseAdapter;import android.widget.Gallery;import android.widget.ImageSwitcher;import android.widget.ImageView;import android.widget.AdapterView.OnItemSelectedListener;import android.widget.Gallery.LayoutParams;import android.widget.ViewSwitcher.ViewFactory;public class testImageView extends Activity implements ViewFactory { private ImageSwitcher is; private Gallery gallery; private int downX,upX;  private ArrayList<Integer> imgList=new ArrayList<Integer>();//图像ID   @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.main);    //用反射机制来获取资源中的图片ID   Field[] fields = R.drawable.class.getDeclaredFields();   for (Field field : fields)   {   if (!"icon".equals(field.getName()))//除了icon之外的图片   {     int index = 0;  try {   index = field.getInt(R.drawable.class);  } catch (IllegalArgumentException e) {   // TODO Auto-generated catch block   e.printStackTrace();  } catch (IllegalAccessException e) {   // TODO Auto-generated catch block   e.printStackTrace();  }    //保存图片ID    imgList.add(index);   }   }      //设置ImageSwitcher控件 is = (ImageSwitcher) findViewById(R.id.switcher); is.setFactory(this); is.setInAnimation(AnimationUtils.loadAnimation(this,  android.R.anim.fade_in)); is.setOutAnimation(AnimationUtils.loadAnimation(this,  android.R.anim.fade_out)); is.setOnTouchListener(new OnTouchListener(){  /*  * 在ImageSwitcher控件上滑动可以切换图片  */  @Override  public boolean onTouch(View v, MotionEvent event) {  if(event.getAction()==MotionEvent.ACTION_DOWN)  {   downX=(int) event.getX();//取得按下时的坐标   return true;  }  else if(event.getAction()==MotionEvent.ACTION_UP)  {   upX=(int) event.getX();//取得松开时的坐标   int index=0;   if(upX-downX>100)//从左拖到右，即看前一张   {   //如果是第一，则去到尾部   if(gallery.getSelectedItemPosition()==0)     index=gallery.getCount()-1;   else    index=gallery.getSelectedItemPosition()-1;   }   else if(downX-upX>100)//从右拖到左，即看后一张   {   //如果是最后，则去到第一   if(gallery.getSelectedItemPosition()==(gallery.getCount()-1))    index=0;   else    index=gallery.getSelectedItemPosition()+1;   }   //改变gallery图片所选，自动触发ImageSwitcher的setOnItemSelectedListener   gallery.setSelection(index, true);   return true;  }  return false;  }   });  //设置gallery控件 gallery = (Gallery) findViewById(R.id.gallery); gallery.setAdapter(new ImageAdapter(this)); gallery.setOnItemSelectedListener(new OnItemSelectedListener(){  @Override  public void onItemSelected(AdapterView<?> arg0, View arg1,   int position, long arg3) {  is.setImageResource(imgList.get(position));  }  @Override  public void onNothingSelected(AdapterView<?> arg0) {  // TODO Auto-generated method stub  }   }); } //设置ImgaeSwitcher @Override public View makeView() { ImageView i = new ImageView(this); i.setBackgroundColor(0xFF000000); i.setScaleType(ImageView.ScaleType.CENTER);//居中 i.setLayoutParams(new ImageSwitcher.LayoutParams(//自适应图片大小  LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); return i; } public class ImageAdapter extends BaseAdapter { public ImageAdapter(Context c) {  mContext = c; } public int getCount() {  return imgList.size(); } public Object getItem(int position) {  return position; } public long getItemId(int position) {  return position; } public View getView(int position, View convertView, ViewGroup parent) {  ImageView i = new ImageView(mContext);  i.setImageResource(imgList.get(position));  i.setAdjustViewBounds(true);  i.setLayoutParams(new Gallery.LayoutParams(   LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));  return i; } private Context mContext; }}