GridView的应用一

主要代码：

MainActivitiy:

package com.example.gridview;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.GridView;import android.widget.ImageView;import android.widget.SimpleAdapter;            
public class MainActivity extends Activity {    private GridView smallImageGrid;    private  ImageView  showImage;    private int[] pics;            @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                //查找组件        smallImageGrid=(GridView) this.findViewById(R.id.imagelist);        showImage=(ImageView) this.findViewById(R.id.imageshow);        //实例化图片数组        pics=new int[]{R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,R.drawable.f};
        List<Map<String,Object>> pic_items=new ArrayList<Map<String,Object>>();        for(int pic_id:pics){         Map<String,Object> item=new HashMap<String, Object>();         item.put("pic",pic_id);         pic_items.add(item);        }        SimpleAdapter adapter=new SimpleAdapter(this,pic_items,R.layout.grid,new String[]{"pic"},new int[]{R.id.smallImage});
        smallImageGrid.setAdapter(adapter);                showImage.setImageResource(pics[0]);                smallImageGrid.setOnItemClickListener(new GridViewHandler());    }        public class GridViewHandler implements OnItemClickListener{
  public void onItemClick(AdapterView<?> adapter, View view, int position,    long id) {   showImage.setImageResource(pics[position]);     }         }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.activity_main, menu);        return true;    }
        }

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent" >    <GridView        android:id="@+id/imagelist"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:horizontalSpacing="20dp"        android:numColumns="3"        android:verticalSpacing="10dp" >    </GridView>    <ImageView        android:id="@+id/imageshow"        android:layout_marginTop="20dp"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:adjustViewBounds="true"        /></LinearLayout>

grid.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <ImageView        android:id="@+id/smallImage"        android:layout_width="80dp"        android:layout_height="50dp"/></LinearLayout>

strings.xml

<resources>    <string name="app_name">GridView组件的使用</string>    <string name="hello_world">        Hello world!</string>    <string name="menu_settings">Settings</string>    <string name="title_activity_main">图片展示</string></resources>

主要运行图：