安卓--ListView

Posted 2021-01-17 feifei

实验目的：

学习使用ListView

实验要求：

实现一个列表，其中显示班级学号姓名，提供添加功能，如需要删去某一项，长按该项，通过弹出菜单显示删除功能。

 

 1 package com.flyuz.app3;
 2 
 3 import android.support.v7.app.AppCompatActivity;
 4 import android.os.Bundle;
 5 import android.view.View;
 6 import android.view.MenuItem ;
 7 import android.widget.Button;
 8 import android.widget.ListView;
 9 import android.widget.ArrayAdapter;
10 import android.widget.EditText;
11 import android.widget.PopupMenu;
12 import android.widget.AdapterView;
13 import java.util.List;
14 import java.util.ArrayList;
15 
16 public class MainActivity extends AppCompatActivity {
17     private Button bt_add;
18     private ListView lv;
19 
20     @Override
21     protected void onCreate(Bundle savedInstanceState) {
22         super.onCreate(savedInstanceState);
23         setContentView(R.layout.activity_main);
24         init();
25     }
26 
27     private void init() {
28         bt_add = (Button) findViewById(R.id.bt_add);
29         lv = (ListView) findViewById(R.id.lv);
30         List<String> list = new ArrayList<String>();
31         list.add("班级" + "                    " + "学号" + "                    " + "姓名");
32         list.add("se1" + "             " + "2016012884" + "                 " + "张三");
33         ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);
34         lv.setAdapter(adapter);
35 
36         //设置事件
37         bt_add.setOnClickListener(new View.OnClickListener() {
38             public void onClick(View v) {
39                 EditText et_class = (EditText) findViewById(R.id.et_class);
40                 EditText et_number = (EditText) findViewById(R.id.et_number);
41                 EditText et_name = (EditText) findViewById(R.id.et_name);
42                 String str_class = et_class.getText().toString();
43                 String str_number = et_number.getText().toString();
44                 String str_name = et_name.getText().toString();
45 
46                 ArrayAdapter add_adp = (ArrayAdapter) lv.getAdapter();
47                 add_adp.add(str_class + "             " + str_number + "             " + str_name);
48             }
49         });
50         lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
51             @Override
52             public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {
53                 if (id > 0) {
54                     PopupMenu popup = new PopupMenu(MainActivity.this, view);
55                     popup.getMenuInflater().inflate(R.menu.menu, popup.getMenu());
56                     popup.show();
57                     popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
58                         @Override
59                         public boolean onMenuItemClick(MenuItem item) {
60                             switch (item.getItemId()) {
61                                 case R.id.menu_del:
62                                     ArrayAdapter temp_adp = (ArrayAdapter) lv.getAdapter();
63                                     temp_adp.remove(temp_adp.getItem(position));
64                                     return true;
65                                 default:
66                                     return false;
67                             }
68                         }
69                     });
70                 }
71                 return true;
72             }
73         });
74     }
75 }

MainActivity

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:app="http://schemas.android.com/apk/res-auto"
 4     xmlns:tools="http://schemas.android.com/tools"
 5     android:layout_width="match_parent"
 6     android:layout_height="match_parent"
 7     android:orientation="vertical"
 8     tools:context="com.flyuz.app3.MainActivity">
 9 
10     <LinearLayout
11         android:layout_width="match_parent"
12         android:layout_height="200dp"
13         android:gravity="center"
14         android:orientation="vertical">
15 
16         <LinearLayout
17             android:layout_width="match_parent"
18             android:layout_height="50dp"
19             android:gravity="center"
20             android:orientation="horizontal">
21 
22             <TextView
23                 android:layout_width="50dp"
24                 android:layout_height="40dp"
25                 android:gravity="center"
26                 android:text="班级:" />
27 
28             <EditText
29                 android:id="@+id/et_class"
30                 android:layout_width="150dp"
31                 android:layout_height="40dp" />
32         </LinearLayout>
33 
34         <LinearLayout
35             android:layout_width="match_parent"
36             android:layout_height="50dp"
37             android:gravity="center"
38             android:orientation="horizontal">
39 
40             <TextView
41                 android:layout_width="50dp"
42                 android:layout_height="40dp"
43                 android:gravity="center"
44                 android:text="学号:" />
45 
46             <EditText
47                 android:id="@+id/et_number"
48                 android:layout_width="150dp"
49                 android:layout_height="40dp" />
50         </LinearLayout>
51 
52         <LinearLayout
53             android:layout_width="match_parent"
54             android:layout_height="50dp"
55             android:gravity="center"
56             android:orientation="horizontal">
57 
58             <TextView
59                 android:layout_width="50dp"
60                 android:layout_height="40dp"
61                 android:gravity="center"
62                 android:text="姓名:" />
63 
64             <EditText
65                 android:id="@+id/et_name"
66                 android:layout_width="150dp"
67                 android:layout_height="40dp" />
68         </LinearLayout>
69 
70         <Button
71             android:id="@+id/bt_add"
72             android:layout_width="180dp"
73             android:layout_height="40dp"
74             android:text="添加" />
75 
76     </LinearLayout>
77     <ListView
78         android:id="@+id/lv"
79         android:layout_width="match_parent"
80         android:layout_height="wrap_content"
81         android:longClickable="true" />
82 
83 </LinearLayout>

layoutactivity_main.xml

1 <?xml version="1.0" encoding="utf-8"?>
2 <menu xmlns:android="http://schemas.android.com/apk/res/android">
3     <item
4         android:id="@+id/menu_del"
5         android:title="删除">
6     </item>
7 </menu>

menumenu.xml