07_ListView

　　ListView是用来显示一个列表的控件，它在Android源代码中是继承AbsListView类的，AbsListView类是继承于AdapterView类的，而AdapterView类是继承ViewGroup类的。

　　下面程序的功能：创建ListView，点击Item会显示全部信息。

 1 package com.example.listviewdemo;
 2
 3 import android.support.v7.app.ActionBarActivity;
 4 import android.os.Bundle;
 5 import android.view.View;
 6 import android.widget.AdapterView;
 7 import android.widget.AdapterView.OnItemClickListener;
 8 import android.widget.ArrayAdapter;
 9 import android.widget.ListView;
10 import android.widget.Toast;
11
12 public class MainActivity extends ActionBarActivity implements OnItemClickListener {
13
14     private ListView lv;
15     private ArrayAdapter<ListCellData> adapter;
16
17     @Override
18     protected void onCreate(Bundle savedInstanceState) {
19         super.onCreate(savedInstanceState);
20         setContentView(R.layout.activity_main);
21
22         adapter = new ArrayAdapter<ListCellData>(this, android.R.layout.simple_expandable_list_item_1);
23 //        adapter = new ArrayAdapter<String>(this, R.layout.lsit_cell);
24
25         lv = (ListView) findViewById(R.id.listView1);
26         lv.setAdapter(adapter);
27
28         adapter.add(new ListCellData("张三", "男", 45));
29         adapter.add(new ListCellData("李四", "男", 22));
30         adapter.add(new ListCellData("王五", "女", 33));
31
32         lv.setOnItemClickListener(this);
33
34 //        adapter.add("Hello");
35 //        adapter.add("What?");
36     }
37
38     @Override
39     public void onItemClick(AdapterView<?> parent, View view, int position,
40             long id) {
41         ListCellData data = adapter.getItem(position);
42
43         Toast.makeText(this, String.format("名字： %s, 性别： %s, 年龄： %d", data.getUserName(), data.getSex(), data.getAge()), Toast.LENGTH_SHORT).show();
44
45
46     }
47
48 }

MainActivity

　　带image的ListView：

 1 package com.example.listviewdemo;
 2
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 import android.widget.ListView;
 6
 7 public class CustomListView extends Activity{
 8
 9     private ListView lv;
10
11     @Override
12     protected void onCreate(Bundle savedInstanceState) {
13         // TODO Auto-generated method stub
14         super.onCreate(savedInstanceState);
15         setContentView(R.layout.custom_listview);
16
17         lv = (ListView) findViewById(R.id.lv);
18         lv.setAdapter(new CustomListViewAdapter(this));
19     }
20
21 }

CustomListView

 1 package com.example.listviewdemo;
 2
 3 import android.content.Context;
 4 import android.view.LayoutInflater;
 5 import android.view.View;
 6 import android.view.ViewGroup;
 7 import android.widget.BaseAdapter;
 8 import android.widget.ImageView;
 9 import android.widget.LinearLayout;
10 import android.widget.TextView;
11
12 public class CustomListViewAdapter extends BaseAdapter {
13
14     private Context context = null;
15
16     CustomListViewAdapter(Context context){
17         this.context = context;
18     }
19
20     public Context getContext() {
21         return context;
22     }
23
24     private CustomListCellData[] data = new CustomListCellData[]{
25         new CustomListCellData("imag1", "dec 1", R.drawable.a),
26         new CustomListCellData("imag2", "dec 2", R.drawable.b),
27         new CustomListCellData("imag3", "dec 3", R.drawable.c)
28     };
29
30     @Override
31     public View getView(int position, View convertView, ViewGroup parent) {
32
33 //        TextView tv = null;
34 //
35 //        //这样做的好处：防止重复创建TextView
36 //        //在有view被回收后，convertView就不是null
37 //        if (convertView != null) {
38 //            tv = (TextView) convertView;
39 //        }else {
40 //            tv = new TextView(CustomListView.this);
41 //        }
42 //
43 //        tv.setTextSize(30);
44 //        tv.setText(getItem(position));
45 //
46 //        return tv;
47
48         LinearLayout ll = null;
49         if (convertView != null) {
50             ll = (LinearLayout) convertView;
51         }else {
52             ll = (LinearLayout) LayoutInflater.from(getContext()).inflate(R.layout.custom_listv_cell, null);
53         }
54
55         CustomListCellData data = getItem(position);
56
57         ImageView icon = (ImageView) ll.findViewById(R.id.icon);
58         TextView name = (TextView) ll.findViewById(R.id.name);
59         TextView dec = (TextView) ll.findViewById(R.id.dec);
60
61         icon.setImageResource(data.iconId);
62         name.setText(data.name);
63         dec.setText(data.dec);
64
65         return ll;
66     }
67
68     @Override
69     public long getItemId(int position) {
70         return position;
71     }
72
73     @Override
74     public CustomListCellData getItem(int position) {
75         return data[position];
76     }
77
78     @Override
79     public int getCount() {
80         return data.length;
81     }
82
83 }

CustomListViewAdapter

 1 package com.example.listviewdemo;
 2
 3 public class CustomListCellData {
 4
 5     public CustomListCellData(String name, String dec, int iconId) {
 6         this.name = name;
 7         this.dec = dec;
 8         this.iconId = iconId;
 9     }
10
11     public String name = "";
12     public String dec = "";
13     public int iconId = 0;
14 }

CustomListCellData

 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="horizontal" >
 6
 7     <ImageView
 8         android:layout_width="100dp"
 9         android:layout_height="100dp"
10         android:id="@+id/icon"/>
11
12     <LinearLayout
13         android:layout_weight="1"
14         android:layout_width="wrap_content"
15         android:layout_height="wrap_content"
16         android:orientation="vertical">
17
18         <TextView
19             android:id="@+id/name"
20             android:layout_width="wrap_content"
21             android:layout_height="wrap_content"
22             android:text="Large Text"
23             android:textAppearance="?android:attr/textAppearanceLarge" />
24
25         <TextView
26             android:id="@+id/dec"
27             android:layout_width="wrap_content"
28             android:layout_height="wrap_content"
29             android:text="TextView" />
30
31     </LinearLayout>
32
33 </LinearLayout>

AndroidManifest.xml