安卓--ListView

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。

 

package com.flyuz.app3;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.MenuItem ;
import android.widget.Button;
import android.widget.ListView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.PopupMenu;
import android.widget.AdapterView;
import java.util.List;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    private Button bt_add;
    private ListView lv;

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

    private void init() {
        bt_add = (Button) findViewById(R.id.bt_add);
        lv = (ListView) findViewById(R.id.lv);
        List<String> list = new ArrayList<String>();
        list.add("班级" + "                    " + "学号" + "                    " + "姓名");
        list.add("se1" + "             " + "2016012884" + "                 " + "张三");
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);
        lv.setAdapter(adapter);

        //设置事件
        bt_add.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                EditText et_class = (EditText) findViewById(R.id.et_class);
                EditText et_number = (EditText) findViewById(R.id.et_number);
                EditText et_name = (EditText) findViewById(R.id.et_name);
                String str_class = et_class.getText().toString();
                String str_number = et_number.getText().toString();
                String str_name = et_name.getText().toString();

                ArrayAdapter add_adp = (ArrayAdapter) lv.getAdapter();
                add_adp.add(str_class + "             " + str_number + "             " + str_name);
            }
        });
        lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {
                if (id > 0) {
                    PopupMenu popup = new PopupMenu(MainActivity.this, view);
                    popup.getMenuInflater().inflate(R.menu.menu, popup.getMenu());
                    popup.show();
                    popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                        @Override
                        public boolean onMenuItemClick(MenuItem item) {
                            switch (item.getItemId()) {
                                case R.id.menu_del:
                                    ArrayAdapter temp_adp = (ArrayAdapter) lv.getAdapter();
                                    temp_adp.remove(temp_adp.getItem(position));
                                    return true;
                                default:
                                    return false;
                            }
                        }
                    });
                }
                return true;
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.flyuz.app3.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:gravity="center"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:orientation="horizontal">

            <TextView
                android:layout_width="50dp"
                android:layout_height="40dp"
                android:gravity="center"
                android:text="班级:" />

            <EditText
                android:id="@+id/et_class"
                android:layout_width="150dp"
                android:layout_height="40dp" />
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:orientation="horizontal">

            <TextView
                android:layout_width="50dp"
                android:layout_height="40dp"
                android:gravity="center"
                android:text="学号:" />

            <EditText
                android:id="@+id/et_number"
                android:layout_width="150dp"
                android:layout_height="40dp" />
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:orientation="horizontal">

            <TextView
                android:layout_width="50dp"
                android:layout_height="40dp"
                android:gravity="center"
                android:text="姓名:" />

            <EditText
                android:id="@+id/et_name"
                android:layout_width="150dp"
                android:layout_height="40dp" />
        </LinearLayout>

        <Button
            android:id="@+id/bt_add"
            android:layout_width="180dp"
            android:layout_height="40dp"
            android:text="添加" />

    </LinearLayout>
    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:longClickable="true" />

</LinearLayout>

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