动态刷新ListView

本文主要是介绍动态刷新ListView，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

要刷新ListView，只需要调用其适配器的notifyDataSetChanged()方法即可。

下面的例子是在“ListView的例子”的基础上演化而言，本文仅给出变化的部分。

布局文件：增加了一个按钮，动态增加一个学生记录。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical" ><TextViewandroid:layout_width="fill_parent"android:layout_height="wrap_content"android:text="@string/label_for_listview"/><ListViewandroid:id="@+id/list_view"android:layout_width="fill_parent"android:layout_height="wrap_content"/><Button android:id="@+id/add_student"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="@string/add_student"/></LinearLayout>

Java代码：对之前的代码进行了重构，增加了Button的消息处理，即增加一个学生记录，然后刷新ListView：

package com.example.hellolistview;import java.util.ArrayList;
import java.util.HashMap;import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;public class MainActivity extends Activity {private int student_item_id = R.layout.student_item;private String[] columnNames = new String[] { "name", "score" };private int[] ids = new int[] { R.id.student_name, R.id.student_score };private ArrayList<HashMap<String, Object>> students = new ArrayList<HashMap<String, Object>>();private int student_id = 0;private Context context = null;BaseAdapter adapter = null;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.my_listview);context = this;student_id = 0;ListView listView = (ListView) this.findViewById(R.id.list_view);createStudents();//adapter = new SimpleAdapter(this, students, student_item_id, columnNames, ids);adapter = new AnotherAdapter();listView.setAdapter(adapter);Button addStudent = (Button) this.findViewById(R.id.add_student);addStudent.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {addStudent();adapter.notifyDataSetChanged();}});}private void createStudents() {for (int i = 1; i <= 10; i++) {addStudent();}}private void addStudent() {HashMap<String, Object> map = null;map = new HashMap<String, Object>();map.put(columnNames[0], "student-" + student_id);map.put(columnNames[1], String.valueOf(student_id * 10));student_id++;students.add(map);}public class AnotherAdapter extends BaseAdapter {@Overridepublic int getCount() {return students.size();}@Overridepublic Object getItem(int position) {return students.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (convertView == null) {convertView = LayoutInflater.from(context).inflate(R.layout.student_item, null);}TextView studentName = (TextView) convertView.findViewById(ids[0]);TextView studentScore = (TextView) convertView.findViewById(ids[1]);studentName.setText((CharSequence) students.get(position).get(columnNames[0]));studentScore.setText((CharSequence) students.get(position).get(columnNames[1]));return convertView;}}
}

运行效果：

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