学步园

 本文来自http://blog.csdn.net/hellogv/ ，引用必须注明出处！

       Android的Gallery控件是个很不错的看图控件，大大减轻了开发者对于看图功能的开发，而且效果也比较美观。本文介绍Gallery的用法，用反射机制来动态读取资源中的图片。

       本文的效果图：

main.xml源码:

<?xml version="1.0" encoding="utf-8"?><br /> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"<br /> android:orientation="vertical"<br /> android:layout_width="fill_parent"<br /> android:layout_height="fill_parent"<br /> ><br /> <Gallery android:id="@+id/gallery" android:layout_height="fill_parent" android:layout_width="fill_parent"></Gallery><br /> </LinearLayout><br />

程序源码：

package com.testImageView;</p> <p>import java.lang.reflect.Field;<br /> import java.util.ArrayList;</p> <p>import android.app.Activity;<br /> import android.content.Context;<br /> import android.graphics.Bitmap;<br /> import android.graphics.BitmapFactory;<br /> import android.os.Bundle;<br /> import android.view.View;<br /> import android.view.ViewGroup;<br /> import android.widget.AdapterView;<br /> import android.widget.BaseAdapter;<br /> import android.widget.Gallery;<br /> import android.widget.ImageView;<br /> import android.widget.AdapterView.OnItemClickListener;</p> <p>public class testImageView extends Activity {<br /> private Gallery mGallery;<br /> @Override<br /> public void onCreate(Bundle savedInstanceState) {<br /> super.onCreate(savedInstanceState);<br /> setContentView(R.layout.main);</p> <p> mGallery = (Gallery)findViewById(R.id.gallery);<br /> try {<br /> mGallery.setAdapter(new ImageAdapter(this));<br /> } catch (IllegalArgumentException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> } catch (IllegalAccessException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> }<br /> mGallery.setOnItemClickListener(new OnItemClickListener() {<br /> public void onItemClick(AdapterView parent, View v, int position, long id) {<br /> testImageView.this.setTitle(String.valueOf(position));<br /> }<br /> });<br /> }</p> <p> /*<br /> * class ImageAdapter is used to control gallery source and operation.<br /> */<br /> private class ImageAdapter extends BaseAdapter{<br /> private Context mContext;<br /> private ArrayList<Integer> imgList=new ArrayList<Integer>();<br /> private ArrayList<Object> imgSizes=new ArrayList<Object>();<br /> public ImageAdapter(Context c) throws IllegalArgumentException, IllegalAccessException{<br /> mContext = c;</p> <p> //用反射机制来获取资源中的图片ID和尺寸<br /> Field[] fields = R.drawable.class.getDeclaredFields();<br /> for (Field field : fields)<br /> {<br /> if (!"icon".equals(field.getName()))//除了icon之外的图片<br /> {<br /> int index=field.getInt(R.drawable.class);<br /> //保存图片ID<br /> imgList.add(index);<br /> //保存图片大小<br /> int size[]=new int[2];<br /> Bitmap bmImg=BitmapFactory.decodeResource(getResources(),index);<br /> size[0]=bmImg.getWidth();size[1]=bmImg.getHeight();<br /> imgSizes.add(size);<br /> }<br /> }<br /> }<br /> @Override<br /> public int getCount() {<br /> // TODO Auto-generated method stub</p> <p> return imgList.size();<br /> }</p> <p> @Override<br /> public Object getItem(int position) {<br /> // TODO Auto-generated method stub</p> <p> return position;<br /> }</p> <p> @Override<br /> public long getItemId(int position) {<br /> // TODO Auto-generated method stub</p> <p> return position;<br /> }</p> <p> @Override<br /> public View getView(int position, View convertView, ViewGroup parent) {<br /> // TODO Auto-generated method stub</p> <p> ImageView i = new ImageView (mContext);<br /> //从imgList取得图片ID<br /> i.setImageResource(imgList.get(position).intValue());<br /> i.setScaleType(ImageView.ScaleType.FIT_XY);<br /> //从imgSizes取得图片大小<br /> int size[]= new int[2];<br /> size=(int[]) imgSizes.get(position);<br /> i.setLayoutParams(new Gallery.LayoutParams(size[0], size[1]));<br /> return i;<br /> }</p> <p> };<br /> }