动态添加元素到ListView的Andr​​oid [英] Dynamically add elements to a listView Android

问题描述

谁能解释或提出了一个教程，创建Android的列表视图？

Can anyone explain or suggest a tutorial to create a listView in android?

下面是我的要求：

• 我应该能够动态地添加由pressing一个按钮，新的元素。
  
• 应该是非常简单理解（有可能没有任何业绩改善或convertview，例如）

我知道有相当多的问题，关于这个主题，在这里StackOverflow的发布，但找不到任何会回答我的问题。谢谢！

I know there are quite a few questions on this topic, posted here on StackOverflow, but couldn't find any that would answer my question. Thanks!

推荐答案

首先创建一个XML布局在项目的 RES /布局/ main.xml中文件夹：

Create an XML layout first in your project's res/layout/main.xml folder:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
    <Button
        android:id="@+id/addBtn"
        android:text="Add New Item"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="addItems"/>
    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:drawSelectorOnTop="false"
    />
</LinearLayout>

这是在顶部的一个按钮，并在底部有一个列表视图一个简单的布局。请注意，的ListView ID为 @android：ID /列表定义默认的ListView A ListActivity 可以使用。

This is a simple layout with a button on the top and a list view on the bottom. Note that the ListView has the id @android:id/list which defines the default ListView a ListActivity can use.

public class ListViewDemo extends ListActivity {
    //LIST OF ARRAY STRINGS WHICH WILL SERVE AS LIST ITEMS
    ArrayList<String> listItems=new ArrayList<String>();

    //DEFINING A STRING ADAPTER WHICH WILL HANDLE THE DATA OF THE LISTVIEW
    ArrayAdapter<String> adapter;

    //RECORDING HOW MANY TIMES THE BUTTON HAS BEEN CLICKED
    int clickCounter=0;

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        adapter=new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1,
            listItems);
        setListAdapter(adapter);
    }

    //METHOD WHICH WILL HANDLE DYNAMIC INSERTION
    public void addItems(View v) {
        listItems.add("Clicked : "+clickCounter++);
        adapter.notifyDataSetChanged();
    }
}

android.R.layout.simple_list_item_1 是搭载Android提供的默认列表项的布局，您可以使用此股票布局不复杂的事情。

android.R.layout.simple_list_item_1 is the default list item layout supplied by Android, and you can use this stock layout for non-complex things.

时listItems 是一个List它保存在ListView中显示的数据。所有的插入和移除应该对时listItems 进行;的变化，时listItems 应反映在视图中。这是由处理 ArrayAdapter＆LT;字符串＆GT;适配器，应使用通知：

listItems is a List which holds the data shown in the ListView. All the insertion and removal should be done on listItems; the changes in listItems should be reflected in the view. That's handled by ArrayAdapter<String> adapter, which should be notified using:

adapter.notifyDataSetChanged（）;

这是适配器实例化3个参数：上下文，这可能是你的活动/ listactivity ;你的个人列表项的布局;并且最后，所述列表，这是实际的数据被显示在列表中。

An Adapter is instantiated with 3 parameters: the context, which could be your activity/listactivity; the layout of your individual list item; and lastly, the list, which is the actual data to be displayed in the list.

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