Android学习之GridView网格视图

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">
	<GridView
		android:id="@+id/myGridView"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:numColumns="3"
		android:stretchMode="columnWidth"/>
</LinearLayout>

 

 

 

grid_layout.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="horizontal" 
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:background="#000000">
	<ImageView
		android:id="@+id/img"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:scaleType="center"
		android:padding="3px"/>
</LinearLayout>

 

 

 

show_img.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">
	<ImageView
		android:id="@+id/showImg"
		android:layout_width="fill_parent"
		android:layout_height="fill_parent"/>
</LinearLayout>

 

 

 

MyGridViewDemo.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.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Gallery.LayoutParams;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.SimpleAdapter;

public class MyGridViewDemo extends Activity {
	private List<Map<String,Integer>> list = new ArrayList<Map<String,Integer>>() ;
	private SimpleAdapter simpleAdapter = null; 				// 适配器
	private GridView myGridView = null ;						// GridView组件
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		super.setContentView(R.layout.main);					// 调用布局管理器
		this.myGridView = (GridView) super.findViewById(R.id.myGridView) ;	// 取得组件
		this.initAdapter() ;									// 初始化适配器
		this.myGridView.setAdapter(this.simpleAdapter) ;		// 设置图片
		this.myGridView.setOnItemClickListener(new OnItemClickListenerImpl()) ;
	}

	private class OnItemClickListenerImpl implements OnItemClickListener {
		@SuppressWarnings("unchecked")
		@Override
		public void onItemClick(AdapterView<?> parent, View view, int position,
				long id) {										// 选项单击事件
			ImageView showImg = new ImageView(MyGridViewDemo.this); // 定义图片组件
			showImg.setScaleType(ImageView.ScaleType.CENTER);	// 居中显示
			showImg.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
					LayoutParams.WRAP_CONTENT));				// 布局参数
			Map<String, Integer> map = (Map<String, Integer>) MyGridViewDemo
				.this.simpleAdapter.getItem(position); 			// 取出Map
			showImg.setImageResource(map.get("img")); 			// 设置显示图片
			Dialog dialog = new AlertDialog.Builder(MyGridViewDemo.this)	// 创建Dialog
					.setIcon(R.drawable.pic_m)					// 设置显示图片
					.setTitle("查看图片")							// 设置标题
					.setView(showImg)							// 设置组件
					.setNegativeButton("关闭",				// 设置取消按钮
							new DialogInterface.OnClickListener() {
								public void onClick(DialogInterface dialog,
										int whichButton) {
								}}).create();					// 创建对话框
			dialog.show();										// 显示对话框

		}
	}
	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("png_")){ 		// 所有png_*命名的图片
				Map<String,Integer> map = new HashMap<String,Integer>() ;	// 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
	}
}