Android学习之图片画廊（SimpleAdapter）

main.xml:

 

 

 

grid_layout.xml:

 

 

 

MyGalleryDemo.java:

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.LinearLayout.LayoutParams;
import android.widget.SimpleAdapter;
import android.widget.ViewSwitcher.ViewFactory;

public class MyGalleryDemo extends Activity {
	private Gallery gallery = null; 							// 图片浏览
	private List> list = new ArrayList>() ;
	private SimpleAdapter simpleAdapter = null; 				// 适配器
	private ImageSwitcher myImageSwitcher = null ;				// 图片切换
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		super.setContentView(R.layout.main);					// 调用布局文件
		this.initAdapter() ;									// 初始化适配器
		this.gallery = (Gallery) super.findViewById(R.id.myGallery) ;// 取得组件
		this.myImageSwitcher = (ImageSwitcher) super
				.findViewById(R.id.myImageSwitcher);			// 取得组件

		this.myImageSwitcher.setFactory(new ViewFactoryImpl()) ;// 设置图片工厂
		this.gallery.setAdapter(this.simpleAdapter);				// 设置图片集
		this.gallery.setOnItemClickListener(new OnItemClickListenerImpl()) ;// 设置单击事件
	}
	private class OnItemClickListenerImpl implements OnItemClickListener {
		@SuppressWarnings("unchecked")
		@Override
		public void onItemClick(AdapterView parent, View view, int position,
				long id) { 
			Map map = (Map) MyGalleryDemo
				.this.simpleAdapter.getItem(position); 					// 取出Map
			MyGalleryDemo.this.myImageSwitcher
				.setImageResource(map.get("img")); 						// 设置显示图片
		}
	}
	public void initAdapter(){									// 初始化适配器
		Field[] fields = R.drawable.class.getDeclaredFields(); 
		for (int x = 0; x < fields.length; x++) {	
			if (fields[x].getName().startsWith("ispic_")){ 		// 所有ispic_*命名的图片
				Map map = new HashMap() ;	// 定义Map
				try {
					map.put("img", fields[x].getInt(R.drawable.class)) ;
				} catch (Exception e) {							// 设置图片资源
				}
				this.list.add(map) ;							// 保存Map
			}
		}
		this.simpleAdapter = new SimpleAdapter(this, 			// 实例化SimpleAdapter
				this.list,										// 要包装的数据集合
				R.layout.grid_layout, 							// 要使用的显示模板
				new String[] { "img" }, 						// 定义要显示的Map的Key
				new int[] {R.id.img });							// 与模板中的组件匹配
	}
	private class ViewFactoryImpl implements ViewFactory {			// 定义视图工厂类
		@Override
		public View makeView() {
			ImageView img = new ImageView(MyGalleryDemo.this);		// 实例化图片显示
			img.setBackgroundColor(0xFFFFFFFF);						// 设置背景颜色
			img.setScaleType(ImageView.ScaleType.CENTER);			// 居中显示
			img.setLayoutParams(new ImageSwitcher.LayoutParams(		// 自适应图片大小
				LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));// 定义组件
			return img;
		}
	}

}