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
  }
}