38.Android之ListView简单学习(一)

android中ListView用的很普遍，今天来学习下，本篇主要以本地数据加载到listview,后面会学习从网络获取数据添加到listview。

首先改下布局文件：

 <?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" >

      <ListView
         android:id="@+id/listview"
         android:layout_width="match_parent"
         android:layout_height="wrap_content" >
     </ListView>  

 </LinearLayout>

SimpleAdapter对应布局文件：

 <?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" >

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical" >

         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="50dp" >

             <LinearLayout
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
                 android:orientation="vertical" >

                 <ImageView
                     android:id="@+id/img"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content" />
             </LinearLayout>

             <LinearLayout
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
                 android:layout_weight="1"
                 android:orientation="vertical" >

                 <LinearLayout
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
                     android:layout_weight="1"
                     android:orientation="vertical" >

                     <TextView
                         android:id="@+id/appnametext"
                         android:layout_width="wrap_content"
                         android:layout_height="match_parent"
                         android:gravity="center"
                         android:text="weixin" />
                 </LinearLayout>

                 <LinearLayout
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
                     android:layout_weight="1"
                     android:orientation="horizontal" >

                     <TextView
                         android:id="@+id/sizetext"
                         android:layout_width="wrap_content"
                         android:layout_height="wrap_content"
                         android:layout_gravity="center"
                         android:text="15.23" />

                     <View
                         android:layout_width="1dp"
                         android:layout_height="match_parent"
                         android:layout_marginBottom="5dp"
                         android:layout_marginLeft="7dp"
                         android:layout_marginRight="3dp"
                         android:layout_marginTop="5dp"
                         android:background="#000000" />

                     <TextView
                         android:id="@+id/amounttext"
                         android:layout_width="wrap_content"
                         android:layout_height="wrap_content"
                         android:layout_gravity="center"
                         android:layout_marginLeft="2dp"
                         android:text="1234567" />
                 </LinearLayout>
             </LinearLayout>

             <LinearLayout
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
                 android:orientation="vertical" >

                 <Button
                     android:id="@+id/dowmbutton"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
                     android:layout_marginLeft="5dp"
                     android:layout_marginRight="10dp"
                     android:text="load" />
             </LinearLayout>
         </LinearLayout>
     </LinearLayout>

 </LinearLayout>

修改下MainActivity.java文件：

 package com.example.listviewdemo1;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
 import android.widget.Button;
 import android.widget.ImageView;
 import android.widget.ListView;
 import android.widget.ListAdapter;
 import android.widget.SimpleAdapter;
 import android.widget.TextView;

 public class MainActivity extends Activity {

     private ListView listView;
     private Intent intent;
     private List<Map<String, Object>> mData;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);

         listView = (ListView) findViewById(R.id.listview);
         SimpleAdapter simpleAdapter = new SimpleAdapter(this, getData(),
                 R.layout.simp_adap, new String[] { "nametext", "teitext",
                         "amounttext" }, new int[] { R.id.appnametext,
                         R.id.sizetext, R.id.amounttext });
         listView.setAdapter(simpleAdapter);
         mData = getData();
         MyAdapter adapter = new MyAdapter(this);
         listView.setAdapter(adapter);

     }

     public List<Map<String, Object>> getData() {
         List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
         Map<String, Object> map = new HashMap<String, Object>();

         map.put("appnametext", "微信");
         map.put("sizetext", "15.2");
         map.put("amounttext", "1234323");
         map.put("appimg", R.drawable.weixin);
         list.add(map);

         map = new HashMap<String, Object>();
         map.put("appnametext", "手机QQ");
         map.put("sizetext", "8.5");
         map.put("amounttext", "122073323");
         map.put("appimg", R.drawable.qq);
         list.add(map);

         map = new HashMap<String, Object>();
         map.put("appnametext", "手机QQ空间");
         map.put("sizetext", "6.3");
         map.put("amounttext", "122393");
         map.put("appimg", R.drawable.qqko);
         list.add(map);

         map = new HashMap<String, Object>();
         map.put("appnametext", "微博");
         map.put("sizetext", "7.7");
         map.put("amounttext", "1278323");
         map.put("appimg", R.drawable.weib);
         list.add(map);

         map = new HashMap<String, Object>();
         map.put("appnametext", "陌陌");
         map.put("sizetext", "6.9");
         map.put("amounttext", "1279073");
         map.put("appimg", R.drawable.mom);
         list.add(map);

         map = new HashMap<String, Object>();
         map.put("appnametext", "飞信");
         map.put("sizetext", "6.9");
         map.put("amounttext", "1279073");
         map.put("appimg", R.drawable.fei);
         list.add(map);
         return list;
     }

     public final class ViewHolder {
         public ImageView appimg;
         public TextView appnametext;
         public TextView sizetext;
         public TextView amounttext;
         public Button dowmbutton;
     }

     public class MyAdapter extends BaseAdapter {

         private LayoutInflater mInflater;

         public MyAdapter(Context context) {
             this.mInflater = LayoutInflater.from(context);
         }

         @Override
         public int getCount() {
             return mData.size();
         }

         @Override
         public Object getItem(int arg0) {
             return null;
         }

         @Override
         public long getItemId(int arg0) {
             // TODO Auto-generated method stub
             return 0;
         }

         @Override
         public View getView(int arg0, View arg1, ViewGroup arg2) {
             // TODO Auto-generated method stub
             ViewHolder holder = null;
             if (arg1 == null) {
                 holder = new ViewHolder();
                 arg1 = mInflater.inflate(R.layout.simp_adap,null);
                 holder.appimg = (ImageView) arg1.findViewById(R.id.img);
                 holder.appnametext = (TextView) arg1.findViewById(R.id.appnametext);
                 holder.sizetext = (TextView) arg1.findViewById(R.id.sizetext);
                 holder.amounttext = (TextView) arg1.findViewById(R.id.amounttext);
                 holder.dowmbutton = (Button) arg1.findViewById(R.id.dowmbutton);
                 arg1.setTag(holder);
             } else {
                 holder = (ViewHolder) arg1.getTag();
             }

             holder.appimg.setBackgroundResource((Integer) mData.get(arg0).get("appimg"));
             holder.appnametext.setText((String) mData.get(arg0).get("appnametext"));
             holder.sizetext.setText((String) mData.get(arg0).get("sizetext"));
             holder.amounttext.setText((String) mData.get(arg0).get("amounttext"));

             return arg1;
         }

     }

 }

运行效果：