Xamarin.Android 的自動完成

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AutoCompleteTextView 是可編輯的文字檢視專案，會在使用者輸入時自動顯示完成建議。 建議清單會顯示在下拉功能表中，使用者可以選擇專案來取代編輯方塊的內容。

Example of Auto Complete

概觀

若要建立提供自動完成建議的文字專案小工具，請使用 AutoCompleteTextView 部件。 建議會透過 從與小工具 ArrayAdapter相關聯的字串集合接收。

在本教學課程中，您將建立 AutoCompleteTextView 小工具，提供國家/地區名稱的建議。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="5dp">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Country" />
    <AutoCompleteTextView android:id="@+id/autocomplete_country"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp"/>
</LinearLayout>

TextView是引進的標籤AutoCompleteTextView 部件。

教學課程

啟動名為 HelloAutoComplete 的新專案。

建立名為 list_item.xml 的 XML 檔案，並將它儲存在 Resources/Layout 資料夾中。 將此檔案的建置動作設定為 AndroidResource。 編輯檔案，如下所示：

<?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="10dp"
    android:textSize="16sp"
    android:textColor="#000">
</TextView>

此檔案會定義一 TextView 個簡單的 ，將用於建議清單中出現的每個專案。

開啟 Resources/Layout/Main.axml 並插入下列專案：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="5dp">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Country" />
    <AutoCompleteTextView android:id="@+id/autocomplete_country"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp"/>
</LinearLayout>

開啟 MainActivity.cs 並插入下列程序代碼 OnCreate() 方法：

protected override void OnCreate (Bundle bundle)
{
    base.OnCreate (bundle);

    // Set our view from the "Main" layout resource
    SetContentView (Resource.Layout.Main);

    AutoCompleteTextView textView = FindViewById<AutoCompleteTextView> (Resource.Id.autocomplete_country);
    var adapter = new ArrayAdapter<String> (this, Resource.Layout.list_item, COUNTRIES);

    textView.Adapter = adapter;
}

將內容檢視設定為 main.xml 版面配置之後，AutoCompleteTextView 小工具是使用 FindViewById從版面配置擷取。 然後，系統會初始化新的 ArrayAdapter ，以將 list_item.xml 配置系結至字串陣列中的每個 COUNTRIES 清單專案（在下一個步驟中定義）。 最後，SetAdapter()呼叫 以將 與產生關聯ArrayAdapterAutoCompleteTextView widget 讓字串數位填入建議清單。

在類別內 MainActivity ，新增字串數位：

static 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"
};

這是當使用者輸入 時，會在下拉式清單中提供的建議清單 AutoCompleteTextView 部件。

執行應用程式。 當您輸入時，應該會看到類似如下的內容：

Example auto-complete screenshot listing names that contain

相關資訊

請注意，使用硬式編碼字串數位並不是建議的設計做法，因為您的應用程式程式代碼應該著重於行為，而不是內容。 應用程式內容，例如字串應該從程式碼外部化，以便更輕鬆地修改內容，並協助當地語系化內容。 硬式編碼字串只會在本教學課程中使用，使其簡單且著重於 AutoCompleteTextView 部件。 相反地，您的應用程式應該在 XML 檔案中宣告這類字串數位。 這可以使用項目res/values/strings.xml檔中的資源來完成<string-array>。 例如：

<?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>

若要針對 ArrayAdapter使用這些資源字串，請取代原始的 ArrayAdapter 建構函式行包含下列專案：

string[] countries = Resources.GetStringArray (Resource.array.countries_array);
var adapter = new ArrayAdapter<String> (this, Resource.layout.list_item, countries);

參考資料

此頁面的部分是根據 Android 開放原始碼專案所建立和共用的工作進行修改，並根據 Creative Commons 2.5 屬性授權中所述的詞彙使用。 本教學課程是以Android自動完成教學課程*為基礎。