Android（二十六）：Spinner 列表下拉选择框

展示

源码

• 主布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#f8f9f8"
    android:padding="10dp">

    <TextView
        android:id="@+id/text_00"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="spinnerMode（dropdown）" />
    
    <Spinner
        android:id="@+id/spinner_00"
        android:layout_below="@id/text_00"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:spinnerMode="dropdown"
        android:entries="@array/heroes" />

    <TextView
        android:id="@+id/text_01"
        android:layout_below="@id/spinner_00"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="spinnerMode（dialog）" />
    
    <Spinner
        android:id="@+id/spinner_01"
        android:layout_below="@id/text_01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:spinnerMode="dialog"
        android:entries="@array/heroes" />

    <TextView
        android:id="@+id/text_02"
        android:layout_below="@id/spinner_01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="自定义样式（仅在dropdown下生效）" />
    
    <Spinner
        android:id="@+id/spinner_02"
        android:layout_below="@id/text_02"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
    
        android:dropDownHorizontalOffset="50dp"
        android:dropDownVerticalOffset="100dp"
        android:dropDownSelector="@color/colorPrimaryDark"
        android:dropDownWidth="200dp"
        android:popupBackground="@color/colorAccent"
        android:spinnerMode="dropdown"
        android:entries="@array/heroes" />

    <TextView
        android:id="@+id/text_03"
        android:layout_below="@id/spinner_02"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="自定义" />

    <Spinner
        android:id="@+id/spinner_03"
        android:layout_below="@id/text_03"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    spinnerMode="dropdown" 生效
        dropDownHorizontalOffset    下拉框水平偏移
        dropDownVerticalOffset      下拉框垂直偏移
        dropDownSelector            下拉框选中背景颜色
        popupBackground             下拉框背景颜色
        dropDownWidth               下拉框宽度
    spinnerMode                 下拉框显示的形式(dialog：对话框风格的窗口, dropdown：下拉菜单风格的窗口(默认))
    entries                     下拉框数据

</RelativeLayout>

• 选项布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="wrap_content"
    android:layout_height="50dp">

    <ImageView
        android:id="@+id/avatar"
        android:layout_width="50dp"
        android:layout_height="match_parent"
        android:layout_marginRight="10dp"/>
    
    <TextView
        android:id="@+id/say"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:gravity="center"/>
    
</LinearLayout>

• 数据

<string-array name="heroes">
    <item>刘备</item>
    <item>关羽</item>
    <item>张飞</item>
    <item>李二蛋</item>
</string-array>

• 脚本

var spinner_03 = (Spinner)FindViewById(Resource.Id.spinner_03);
IList<IDictionary<string, object>> list = new JavaList<IDictionary<string, object>>
{
    new JavaDictionary<string, object>
    {
        { "avatar", Resource.Drawable.avatar },
        { "say", "人海茫茫，你我依旧孤独～～～" }
    },
    new JavaDictionary<string, object>
    {
        { "avatar", Resource.Drawable.avatar },
        { "say", "谁又能来拯救我这灰暗的人生呢……" }
    },
    new JavaDictionary<string, object>
    {
        { "avatar", Resource.Drawable.avatar },
        { "say", "道不尽世间的沧桑，诉不完人生的悲凉！" }
    }
};
var keys = new[] { "avatar", "say" };
var targets = new[] { Resource.Id.avatar, Resource.Id.say };
var simpleAdapter = new SimpleAdapter(this, list, Resource.Layout.spinner_item, keys, targets);
if (spinner_03 == null) return;
spinner_03.Adapter = simpleAdapter;
spinner_03.ItemSelected += (sender, args) =>
{
    var say = (TextView)args.View?.FindViewById(Resource.Id.say);
    Toast.MakeText(this, say?.Text, ToastLength.Long)?.Show();
};