Hello Views之List View（yaozq翻译，仅供参考）

ListView是创建滚动列表的ViewGroup。列表中的item是通过ListAdapter自动插入的。

在这个教程中，你将创建一个从字符串数组读入的国家名称的滚动列表。当一个item被选中的时候，一个表明item在列表中位置的Toast信息将会显示出来。下面是具体步骤：

1，新建一个名为HelloListView的项目。

2，创建一个名为list_item.xml的XML文件，并将其保存在res/layout/文件夹下，插入下面的内容：

<?xml version="1.0" encoding="utf-8"?><TextView xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"android:padding="10dip"android:textSize=16sp""/>

这个文件定义了ListView中每一个item的布局方式。

3，打开HelloListView.java，写一个继承自ListActivity的类（不是Activity）。

public class HelloListView extends ListActivity{}

4，在onCreate()方法中，插入以下代码：

@Overridepublic void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, COUNTRIES));  ListView lv = getListView();  lv.setTextFilterEnabled(true);  lv.setOnItemClickListener(new OnItemClickListener() {    public void onItemClick(AdapterView<?> parent, View view,        int position, long id) {      // When clicked, show a toast with the TextView text      Toast.makeText(getApplicationContext(), ((TextView) view).getText(),          Toast.LENGTH_SHORT).show();    }  });}

注意这并不会为Activity加载一个布局文件（我们通常使用setContentView(int)来做的）。而是通过setListAdapter(ListAdapter)方法会自动将一个ListView填充ListActivity的整个屏幕。这个方法需要一个ArrayAdapter作为参数，这个ArrayAdapter参数用来管理放到ListView中的字符串数组。ArrayAdapter的参数有程序的Context，每一个list item的布局方式，插入到ListView中的一个List对象（接下来定义）。

setTextFilterEnable(boolean)方法为ListView进行文本过滤，这样到用户输入的时候，这个list会自动过滤出符合要求的。

setOnItemClickListener(OnItemClickListener)方法用来为每一个item定义on-click监听器。当listView中的一个item被点击之后，onItemClick()方法会被调用，并且一个Toast信息将会，来显示被点击的item。

Tip：你可以使用平台提供的list item布局设计来代替你自己为ListAdapter定义的布局方式。比如，你可以用android.R.layout.simple_list_item_1来代替R.layout.list_item。

5，在onCreate()方法之后，增加下面的数组：

static final String[] COUNTRIES = new String[] {    "Afghanistan", "Albania", "Algeria", "American Samoa", "Andorra",    "Angola", "Anguilla", "Antarctica", "Antigua and Barbuda", "Argentina",    "Armenia", "Aruba", "Australia", "Austria", "Azerbaijan",    "Bahrain", "Bangladesh", "Barbados", "Belarus", "Belgium",    "Belize", "Benin", "Bermuda", "Bhutan", "Bolivia",    "Bosnia and Herzegovina", "Botswana", "Bouvet Island", "Brazil", "British Indian Ocean Territory",    "British Virgin Islands", "Brunei", "Bulgaria", "Burkina Faso", "Burundi",    "Cote d'Ivoire", "Cambodia", "Cameroon", "Canada", "Cape Verde",    "Cayman Islands", "Central African Republic", "Chad", "Chile", "China",    "Christmas Island", "Cocos (Keeling) Islands", "Colombia", "Comoros", "Congo",    "Cook Islands", "Costa Rica", "Croatia", "Cuba", "Cyprus", "Czech Republic",    "Democratic Republic of the Congo", "Denmark", "Djibouti", "Dominica", "Dominican Republic", "East Timor", "Ecuador", "Egypt", "El Salvador", "Equatorial Guinea", "Eritrea",    "Estonia", "Ethiopia", "Faeroe Islands", "Falkland Islands", "Fiji", "Finland",    "Former Yugoslav Republic of Macedonia", "France", "French Guiana", "French Polynesia",    "French Southern Territories", "Gabon", "Georgia", "Germany", "Ghana", "Gibraltar",    "Greece", "Greenland", "Grenada", "Guadeloupe", "Guam", "Guatemala", "Guinea", "Guinea-Bissau", "Guyana", "Haiti", "Heard Island and McDonald Islands", "Honduras", "Hong Kong", "Hungary","Iceland", "India", "Indonesia", "Iran", "Iraq", "Ireland", "Israel", "Italy", "Jamaica","Japan", "Jordan", "Kazakhstan", "Kenya", "Kiribati", "Kuwait", "Kyrgyzstan", "Laos",    "Latvia", "Lebanon", "Lesotho", "Liberia", "Libya", "Liechtenstein", "Lithuania", "Luxembourg", "Macau", "Madagascar", "Malawi", "Malaysia", "Maldives", "Mali", "Malta", "Marshall Islands","Martinique", "Mauritania", "Mauritius", "Mayotte", "Mexico", "Micronesia", "Moldova", "Monaco", "Mongolia", "Montserrat", "Morocco", "Mozambique", "Myanmar", "Namibia", "Nauru", "Nepal", "Netherlands", "Netherlands Antilles", "New Caledonia", "New Zealand", "Nicaragua", "Niger", "Nigeria", "Niue", "Norfolk Island", "North Korea", "Northern Marianas", "Norway", "Oman", "Pakistan", "Palau", "Panama", "Papua New Guinea", "Paraguay", "Peru","Philippines", "Pitcairn Islands", "Poland", "Portugal", "Puerto Rico", "Qatar",    "Reunion", "Romania", "Russia", "Rwanda", "Sqo Tome and Principe", "Saint Helena",    "Saint Kitts and Nevis", "Saint Lucia", "Saint Pierre and Miquelon",    "Saint Vincent and the Grenadines", "Samoa", "San Marino", "Saudi Arabia", "Senegal",    "Seychelles", "Sierra Leone", "Singapore", "Slovakia", "Slovenia", "Solomon Islands",    "Somalia", "South Africa", "South Georgia and the South Sandwich Islands", "South Korea",    "Spain", "Sri Lanka", "Sudan", "Suriname", "Svalbard and Jan Mayen", "Swaziland", "Sweden","Switzerland", "Syria", "Taiwan", "Tajikistan", "Tanzania", "Thailand", "The Bahamas","The Gambia", "Togo", "Tokelau", "Tonga", "Trinidad and Tobago", "Tunisia", "Turkey", "Turkmenistan", "Turks and Caicos Islands", "Tuvalu", "Virgin Islands", "Uganda",    "Ukraine", "United Arab Emirates", "United Kingdom",    "United States", "United States Minor Outlying Islands", "Uruguay", "Uzbekistan",    "Vanuatu", "Vatican City", "Venezuela", "Vietnam", "Wallis and Futuna", "Western Sahara",    "Yemen", "Yugoslavia", "Zambia", "Zimbabwe"  };

这就是讲被放入到ListView中的字符串数组。

6，运行这个程序。

你可以拖动这个list，或者输入并过滤，然后单击一个item查看Toast信息，你将会看到类似如下的结果：

注意使用一个硬编码的字符串数组并不是一种最好的设计习惯。教程中的这种方式只是为了简便。更好的习惯是使用另外的资源来定义字符串数组，比如在你项目中的res/values/string.xml文件中使用<string-array>定义数组资源。比如：

<?xml version="1.0" encoding="utf-8"?><resources>    <string-array name="countries_array">        <item>Bahrain</item>        <item>Bangladesh</item>        <item>Barbados</item>        <item>Belarus</item>        <item>Belgium</item>        <item>Belize</item>        <item>Benin</item>    </string-array></resources>

用下面的代码，替换上文中的setListAdapter(ListAdapter)：

String[] countries = getResources().getStringArray(R.array.countries_array);setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, countries));