WP开发-Toolkit组件 列表采集器(ListPicker)的使用

列表采集器ListPicker在作用上与html中的<select/>标签一样 都是提供多选一功能，区别在于ListPicker可以自定义下拉状态和非下拉状态的样式。

1.模板设置

ListPicker有两个模板属性

• ItemTemplate 文本框显示的单个选项模板
• FullModeItemTemplate 所有选项列表的模板

与之相关的还有一个数字类型的属性：ItemCountThreshold

如果ListPicker中的选项数量小于该属性的值的话 则显示方式是普通下拉菜单

但如果大于该属性值，则下拉菜单会全屏显示  如下图

回到那两个模板，ItemTemplate 针对的是ListPicker初始状态（点击前 和选中后）及处于下拉菜单状态（即非全屏状态）时每一项

而FullModeItemTemplate 这针对的是全屏状态时每一项

注：如果不设定 ItemCountThreshold 则点击后始终是普通菜单而不会全屏

2.Header

ListPicker的标题 如第一个图中的default ，Cities

3.FullModeHeader

全屏状态时顶部的标题 如第三张图中的Cities-Full

4.SelectedIndex

设定或获取选定项的序号

相关代码：

XAML

        <!--定义模板资源-->
        <Grid.Resources>
            <DataTemplate x:Name="PickerItemTemplate">
                <StackPanel Orientation="Horizontal">
                    <Border Background="Red" Width="34" Height="34">
                        <TextBlock Text="{Binding Country}" FontSize="16"
                            HorizontalAlignment="Center" VerticalAlignment="Center" />
                    </Border>
                    <TextBlock Text="{Binding Name}" Margin="12 0 0 0" />
                </StackPanel>
            </DataTemplate>
            <DataTemplate x:Name="PickerFullModeItemTemplate">
                <StackPanel Orientation="Horizontal" Margin="40 21 0 20">
                    <TextBlock Text="{Binding Name}" Margin="16 0 0 0" FontSize="43"
                        FontFamily="{StaticResource PhoneFontFamilyLight}"/>
                    <TextBlock Text="language: " />
                    <TextBlock Text="{Binding Language}" Foreground="Brown" />
                </StackPanel>
            </DataTemplate>
        </Grid.Resources>

        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <!--未设定模板-->
            <toolkit:ListPicker Header="Default" Margin="12,12,12,0" Grid.Row="1" x:Name="defaultPicker" />
            <!--点击后全屏-->
            <toolkit:ListPicker x:Name="listPickerFull"
                        ItemTemplate="{StaticResource PickerItemTemplate}"
                        FullModeItemTemplate="{StaticResource PickerFullModeItemTemplate}"
                        Grid.Row="0" Header="Cities-Full" Margin="12,110,12,0"
                        SelectedIndex="2" ItemCountThreshold="3"
                        FullModeHeader="Cities-Full-Header" CacheMode="BitmapCache"/>
            <!--点击后非全屏-->
            <toolkit:ListPicker x:Name="listPicker"
                        ItemTemplate="{StaticResource PickerItemTemplate}"
                        FullModeItemTemplate="{StaticResource PickerFullModeItemTemplate}"
                        Grid.Row="0" Header="Cities" Margin="12,210,12,0"
                        SelectedIndex="2" ItemCountThreshold="5"
                        FullModeHeader="Cities" CacheMode="BitmapCache"/>
        </Grid>

后台代码

namespace Phone.Toolkit.Demo
{
    public partial class ListPicker : PhoneApplicationPage
    {
        public ListPicker()
        {
            InitializeComponent();
            List<Cities> source = new List<Cities>() {
                new Cities("Madrid","US","English")
                ,new Cities("Las Vegas","UK","English")
                ,new Cities("London","UK","English")
                ,new Cities("Mexico","MX","Spanish")
            };
            this.listPicker.ItemsSource = source;
            this.listPickerFull.ItemsSource = source;
            this.defaultPicker.ItemsSource = new List<string>() { "Madrid", "Las Vegas", "London" };
        }

    }
    public class Cities
    {
        public string Name { set; get; }
        public string Country { set; get; }
        public string Language { set; get; }
        public Cities(string name, string c, string l)
        {
            this.Name = name;
            this.Country = c;
            this.Language = l;
        }
    }
}