android 这 Gallery的使用

原文引用：http://blog.youkuaiyun.com/hellogv/article/details/5961525

使用 Gallery 查看图片：

main.xml

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

GallerydemoActivity.java

package com.hkrt;

import java.lang.reflect.Field;
import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.AdapterView.OnItemClickListener;

public class GallerydemoActivity extends Activity {
	private Gallery mGallery;  
//	/获取手机屏幕分辨率的类   
    private DisplayMetrics dm;  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
          
        mGallery = (Gallery)findViewById(R.id.gallery);  
        try {  
            mGallery.setAdapter(new ImageAdapter(this));  
        } catch (IllegalArgumentException e) {  
            e.printStackTrace();  
        } catch (IllegalAccessException e) {  
            e.printStackTrace();  
        }  
        mGallery.setOnItemClickListener(new OnItemClickListener() {  
            public void onItemClick(AdapterView parent, View v, int position, long id) {
//                TextView testImageView = (TextView)  findViewById(R.id.testImageView);
//                testImageView.setText(String.valueOf(position));  
            }  
        });  
    }  
      
    /* 
     * class ImageAdapter is used to control gallery source and operation. 
     */  
    private class ImageAdapter extends BaseAdapter{  
        private Context mContext;  
        private ArrayList<Integer> imgList=new ArrayList<Integer>();  
        private ArrayList<Object> imgSizes=new ArrayList<Object>();  
        public ImageAdapter(Context c) throws IllegalArgumentException, IllegalAccessException{  
            mContext = c;  
              
            //用反射机制来获取资源中的图片ID和尺寸  
            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=field.getInt(R.drawable.class);  
                    //保存图片ID  
                    imgList.add(index);  
                    //保存图片大小  
                    int size[]=new int[2];  
                    Bitmap bmImg=BitmapFactory.decodeResource(getResources(),index);  
                    dm = new DisplayMetrics();   
                    getWindowManager().getDefaultDisplay().getMetrics(dm);   
                            //获得手机的宽度和高度像素单位为px   
                    size[0]=dm.widthPixels;//bmImg.getWidth();
                    size[1]=dm.heightPixels;//bmImg.getHeight(); 
                    imgSizes.add(size);  
                }  
            }  
        }  
        @Override  
        public int getCount() {  
            // TODO Auto-generated method stub  
  
            return imgList.size();  
        }  
  
        @Override  
        public Object getItem(int position) {  
            // TODO Auto-generated method stub  
  
            return position;  
        }  
  
        @Override  
        public long getItemId(int position) {  
            // TODO Auto-generated method stub  
  
            return position;  
        }  
  
        @Override  
        public View getView(int position, View convertView, ViewGroup parent) {  
            // TODO Auto-generated method stub  
  
            ImageView i = new ImageView (mContext);  
            //从imgList取得图片ID  
            i.setImageResource(imgList.get(position).intValue());  
            i.setScaleType(ImageView.ScaleType.FIT_XY);  
            //从imgSizes取得图片大小  
            int size[]= new int[2];  
            size=(int[]) imgSizes.get(position);  
            i.setLayoutParams(new Gallery.LayoutParams(size[0], size[1]));  
            return i;  
        }  
          
    };  
}

效果图：