下拉列表

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent" >
 5 
 6     <EditText
 7         android:id="@+id/input"
 8         android:layout_width="200dp"
 9         android:layout_height="wrap_content"
10         android:layout_centerHorizontal="true"
11         android:layout_marginTop="10dp"
12         android:text="@string/hello_world" />
13 
14     <!-- 下啦三角图案 -->
15     <ImageView 
16         android:id="@+id/down_arrow"
17         android:layout_width="wrap_content"
18         android:layout_height="wrap_content"
19         android:background="@drawable/down_arrow"
20         android:layout_alignRight="@id/input"
21         android:clickable="true"
22         android:layout_marginTop="20dp" />
23 </RelativeLayout>

  1 package com.example.testdemo;
  2 
  3 import java.util.ArrayList;
  4 import java.util.List;
  5 import android.app.Activity;
  6 import android.os.Bundle;
  7 import android.view.View;
  8 import android.view.View.OnClickListener;
  9 import android.view.ViewGroup;
 10 import android.widget.BaseAdapter;
 11 import android.widget.EditText;
 12 import android.widget.ImageView;
 13 import android.widget.ListView;
 14 import android.widget.PopupWindow;
 15 import android.widget.TextView;
 16 
 17 public class MainActivity extends Activity {
 18 
 19     private EditText et_input;
 20     private ImageView downArrow;
 21     private List<String> msgList;
 22     private PopupWindow popWin;
 23     private ListView listView;
 24 
 25     @Override
 26     protected void onCreate(Bundle savedInstanceState) {
 27         super.onCreate(savedInstanceState);
 28         setContentView(R.layout.activity_main);
 29 
 30         et_input = (EditText) findViewById(R.id.input);
 31         downArrow = (ImageView) findViewById(R.id.down_arrow);
 32         msgList = new ArrayList<String>();
 33 
 34         for (int i = 0; i < 20; i++) {
 35             msgList.add("1000000000" + i);
 36         }
 37 
 38         initListView();
 39 
 40         downArrow.setOnClickListener(new OnClickListener() {
 42             @Override
 43             public void onClick(View v) {
 44                 System.out.println("=======");
 45                 // 定义 popupWindow
 46                 popWin = new PopupWindow(MainActivity.this);
 47                 // 设置宽度
 48                 popWin.setWidth(et_input.getWidth());
 49                 // 设置popWin 高度
 50                 popWin.setHeight(200);
 51                 // 为popWindow填充内容
 52                 popWin.setContentView(listView);
 53                 // 点击popWin 以处的区域，自动关闭 popWin
 54                 popWin.setOutsideTouchable(true);
 55                 // 设置 弹出窗口，显示的位置
 56                 popWin.showAsDropDown(et_input, 0, 0);
 57             }
 58         });
 59     }
 60 
 61     private void initListView() {
 62         listView = new ListView(this);
 63         // 设置listView背景
 64         listView.setBackgroundResource(R.drawable.listview_background); 
 65         // 设置条目之间的分隔线为null
 66         listView.setDivider(null); 
 67         // 关闭
 68         listView.setVerticalScrollBarEnabled(false); 
 69         listView.setAdapter(new MyListAdapter());
 70     }
 71 
 72     private class MyListAdapter extends BaseAdapter {
 73         @Override
 74         public int getCount() {
 75             return msgList.size();
 76         }
 77         @Override
 78         public Object getItem(int position) {
 79             return position;
 80         }
 81         @Override
 82         public long getItemId(int position) {
 83             return position;
 84         }
 86         @Override
 87         public View getView(final int position, View convertView,
 88                 ViewGroup parent) {
 89             ViewHolder holder;
 90             if (convertView == null) {
 91                 convertView = View.inflate(getApplicationContext(),
 92                         R.layout.list_item, null);
 93                 holder = new ViewHolder();
 94 
 95                 holder.delete = (ImageView) convertView
 96                         .findViewById(R.id.delete);
 97                 holder.tv_msg = (TextView) convertView
 98                         .findViewById(R.id.tv_list_item);
 99                 convertView.setTag(holder);
100             } else {
101                 holder = (ViewHolder) convertView.getTag();
102             }
103             holder.tv_msg.setText(msgList.get(position));
104             holder.delete.setOnClickListener(new OnClickListener() {
106                 @Override
107                 public void onClick(View v) {
108                     // 删除对应的条目
109                     msgList.remove(position);
110                     // 刷新listView
111                     MyListAdapter.this.notifyDataSetChanged();
112                 }
113             });
114             convertView.setOnClickListener(new OnClickListener() {
115                 @Override
116                 public void onClick(View v) {
117                     // 设置输入框
118                     et_input.setText(msgList.get(position));
119                     popWin.dismiss();
120                 }
121             });
122             return convertView;
123         }
124     }
125 
126     private class ViewHolder {
127         TextView tv_msg;
128         ImageView delete;
129     }
130 
131 }