38.Android之ListView简单学习

Posted 2020-06-16

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：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" >
 6 
 7      <ListView  
 8         android:id="@+id/listview"  
 9         android:layout_width="match_parent"  
10         android:layout_height="wrap_content" >  
11     </ListView>  
12     
13 </LinearLayout>

SimpleAdapter对应布局文件：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" >
 6     
 7     <LinearLayout
 8         android:layout_width="match_parent"
 9         android:layout_height="match_parent"
10         android:orientation="vertical" >
11 
12         <LinearLayout
13             android:layout_width="match_parent"
14             android:layout_height="50dp" >
15 
16             <LinearLayout
17                 android:layout_width="wrap_content"
18                 android:layout_height="match_parent"
19                 android:orientation="vertical" >
20 
21                 <ImageView
22                     android:id="@+id/img"
23                     android:layout_width="wrap_content"
24                     android:layout_height="wrap_content" />
25             </LinearLayout>
26 
27             <LinearLayout
28                 android:layout_width="wrap_content"
29                 android:layout_height="match_parent"
30                 android:layout_weight="1"
31                 android:orientation="vertical" >
32 
33                 <LinearLayout
34                     android:layout_width="match_parent"
35                     android:layout_height="wrap_content"
36                     android:layout_weight="1"
37                     android:orientation="vertical" >
38 
39                     <TextView
40                         android:id="@+id/appnametext"
41                         android:layout_width="wrap_content"
42                         android:layout_height="match_parent"
43                         android:gravity="center"
44                         android:text="weixin" />
45                 </LinearLayout>
46 
47                 <LinearLayout
48                     android:layout_width="match_parent"
49                     android:layout_height="wrap_content"
50                     android:layout_weight="1"
51                     android:orientation="horizontal" >
52 
53                     <TextView
54                         android:id="@+id/sizetext"
55                         android:layout_width="wrap_content"
56                         android:layout_height="wrap_content"
57                         android:layout_gravity="center"
58                         android:text="15.23" />
59 
60                     <View
61                         android:layout_width="1dp"
62                         android:layout_height="match_parent"
63                         android:layout_marginBottom="5dp"
64                         android:layout_marginLeft="7dp"
65                         android:layout_marginRight="3dp"
66                         android:layout_marginTop="5dp"
67                         android:background="#000000" />
68 
69                     <TextView
70                         android:id="@+id/amounttext"
71                         android:layout_width="wrap_content"
72                         android:layout_height="wrap_content"
73                         android:layout_gravity="center"
74                         android:layout_marginLeft="2dp"
75                         android:text="1234567" />
76                 </LinearLayout>
77             </LinearLayout>
78 
79             <LinearLayout
80                 android:layout_width="wrap_content"
81                 android:layout_height="match_parent"
82                 android:orientation="vertical" >
83 
84                 <Button
85                     android:id="@+id/dowmbutton"
86                     android:layout_width="wrap_content"
87                     android:layout_height="wrap_content"
88                     android:layout_marginLeft="5dp"
89                     android:layout_marginRight="10dp"
90                     android:text="load" />
91             </LinearLayout>
92         </LinearLayout>
93     </LinearLayout>
94     
95 
96 </LinearLayout>

修改下MainActivity.java文件：

  1 package com.example.listviewdemo1;
  2 
  3 import java.util.ArrayList;
  4 import java.util.HashMap;
  5 import java.util.List;
  6 import java.util.Map;
  7 
  8 import android.app.Activity;
  9 import android.content.Context;
 10 import android.content.Intent;
 11 import android.os.Bundle;
 12 import android.view.LayoutInflater;
 13 import android.view.View;
 14 import android.view.ViewGroup;
 15 import android.widget.BaseAdapter;
 16 import android.widget.Button;
 17 import android.widget.ImageView;
 18 import android.widget.ListView;
 19 import android.widget.ListAdapter;
 20 import android.widget.SimpleAdapter;
 21 import android.widget.TextView;
 22 
 23 public class MainActivity extends Activity {
 24 
 25     private ListView listView;
 26     private Intent intent;
 27     private List<Map<String, Object>> mData;
 28 
 29     @Override
 30     protected void onCreate(Bundle savedInstanceState) {
 31         super.onCreate(savedInstanceState);
 32         setContentView(R.layout.activity_main);
 33 
 34         listView = (ListView) findViewById(R.id.listview);
 35         SimpleAdapter simpleAdapter = new SimpleAdapter(this, getData(),
 36                 R.layout.simp_adap, new String[] { "nametext", "teitext",
 37                         "amounttext" }, new int[] { R.id.appnametext,
 38                         R.id.sizetext, R.id.amounttext });
 39         listView.setAdapter(simpleAdapter);
 40         mData = getData();
 41         MyAdapter adapter = new MyAdapter(this);
 42         listView.setAdapter(adapter);
 43 
 44     }
 45 
 46     public List<Map<String, Object>> getData() {
 47         List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
 48         Map<String, Object> map = new HashMap<String, Object>();
 49 
 50         map.put("appnametext", "微信");
 51         map.put("sizetext", "15.2");
 52         map.put("amounttext", "1234323");
 53         map.put("appimg", R.drawable.weixin);
 54         list.add(map);
 55 
 56         map = new HashMap<String, Object>();
 57         map.put("appnametext", "手机QQ");
 58         map.put("sizetext", "8.5");
 59         map.put("amounttext", "122073323");
 60         map.put("appimg", R.drawable.qq);
 61         list.add(map);
 62 
 63         map = new HashMap<String, Object>();
 64         map.put("appnametext", "手机QQ空间");
 65         map.put("sizetext", "6.3");
 66         map.put("amounttext", "122393");
 67         map.put("appimg", R.drawable.qqko);
 68         list.add(map);
 69 
 70         map = new HashMap<String, Object>();
 71         map.put("appnametext", "微博");
 72         map.put("sizetext", "7.7");
 73         map.put("amounttext", "1278323");
 74         map.put("appimg", R.drawable.weib);
 75         list.add(map);
 76 
 77         map = new HashMap<String, Object>();
 78         map.put("appnametext", "陌陌");
 79         map.put("sizetext", "6.9");
 80         map.put("amounttext", "1279073");
 81         map.put("appimg", R.drawable.mom);
 82         list.add(map);
 83 
 84         map = new HashMap<String, Object>();
 85         map.put("appnametext", "飞信");
 86         map.put("sizetext", "6.9");
 87         map.put("amounttext", "1279073");
 88         map.put("appimg", R.drawable.fei);
 89         list.add(map);
 90         return list;
 91     }
 92 
 93     public final class ViewHolder {
 94         public ImageView appimg;
 95         public TextView appnametext;
 96         public TextView sizetext;
 97         public TextView amounttext;
 98         public Button dowmbutton;
 99     }
100 
101     public class MyAdapter extends BaseAdapter {
102 
103         private LayoutInflater mInflater;
104 
105         public MyAdapter(Context context) {
106             this.mInflater = LayoutInflater.from(context);
107         }
108 
109         @Override
110         public int getCount() {
111             return mData.size();
112         }
113 
114         @Override
115         public Object getItem(int arg0) {
116             return null;
117         }
118 
119         @Override
120         public long getItemId(int arg0) {
121             // TODO Auto-generated method stub
122             return 0;
123         }
124 
125         @Override
126         public View getView(int arg0, View arg1, ViewGroup arg2) {
127             // TODO Auto-generated method stub
128             ViewHolder holder = null;
129             if (arg1 == null) {
130                 holder = new ViewHolder();
131                 arg1 = mInflater.inflate(R.layout.simp_adap,null);
132                 holder.appimg = (ImageView) arg1.findViewById(R.id.img);
133                 holder.appnametext = (TextView) arg1.findViewById(R.id.appnametext);
134                 holder.sizetext = (TextView) arg1.findViewById(R.id.sizetext);
135                 holder.amounttext = (TextView) arg1.findViewById(R.id.amounttext);
136                 holder.dowmbutton = (Button) arg1.findViewById(R.id.dowmbutton);
137                 arg1.setTag(holder);
138             } else {
139                 holder = (ViewHolder) arg1.getTag();
140             }
141 
142             holder.appimg.setBackgroundResource((Integer) mData.get(arg0).get("appimg"));
143             holder.appnametext.setText((String) mData.get(arg0).get("appnametext"));
144             holder.sizetext.setText((String) mData.get(arg0).get("sizetext"));
145             holder.amounttext.setText((String) mData.get(arg0).get("amounttext"));
146 
147             return arg1;
148         }
149 
150     }
151 
152 }

运行效果：