具有DataTemplate的ListPicker的SelectedIndex或SelectedItem

本文关键字：SelectedItem SelectedIndex ListPicker DataTemplate 具有 | 更新日期: 2023-09-27 18:20:55

我使用Listpicker来允许用户选择颜色。因此，我使用了一个带有DataTemplate的Toolkit Listpicker，其中包括显示其列表项的Textbox。我想要的是当页面加载时，之前选择的颜色（项目）会自动被选中。但它给了我一个明显的"System.InvalidOperationException"异常，因为这些项不是简单地添加的，而是通过数据模板文本框添加的。请帮帮我：

 <toolkit:ListPicker x:Name="BackgroundColor"  FullModeHeader="Select Background Color:" Header="Background Color:" BorderThickness="0" FullModeItemTemplate="{StaticResource PickerFullModeItemTemplate}" ItemTemplate="{StaticResource PickerItemTemplate}" Background="#FF09043C" SelectionChanged="BackgroundColor_SelectionChanged" >
           </toolkit:ListPicker>
             <phone:PhoneApplicationPage.Resources>
    <DataTemplate x:Name="PickerItemTemplate">
        <TextBlock Text="{Binding BackGroundColorString}" />
    </DataTemplate>
    <DataTemplate x:Name="PickerFullModeItemTemplate" >
        <Grid x:Name="rootGrid" Margin="0">
            <StackPanel Orientation="Horizontal">
                <TextBlock Name="BackgroundColor" 
                   Text="{Binding BackGroundColorString}"
                          />
            </StackPanel>
        </Grid>
    </DataTemplate>
                     </phone:PhoneApplicationPage.Resources>

if (SunderGutkaSettings.Contains(SG_KEY_BACKGROUNDCOLOR)) //check if key is not present, read value  
        {
            if (BackGroundColorList.Count != 0)//test if list if not empty
            {
                var ListPickerBackGroundColorRead = BackGroundColorList[singletonInstance.SelectedFontColorIndex] as BackGroundlistPickerClass; //pull whole class
                string ListPickerBackGroundColorReadString = ListPickerBackGroundColorRead.BackGroundColorString;
                int ListPickerBackGroundColorReadStringToIndex = BackGroundColorList.FindIndex(x => x.BackGroundColorString.StartsWith(ListPickerBackGroundColorReadString));
                BackgroundColor.SelectedIndex = ListPickerBackGroundColorReadStringToIndex; //DISABLE FOR testing                    

            }

事实上，只要简单地输入我的代码：BackgroundColor.SelectedIndex=0；Doesnt work也没有BackgroundColor.SelectedItem="红色"；

帮助我

具有DataTemplate的ListPicker的SelectedIndex或SelectedItem

要设置项目，

This.BackgroundColor.SelectedItem = YourObject;

这就是获取ListPicker的selecteditem的方法，可能需要将其转换为绑定到列表Picker 的对象

    private void BackgroundColor_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
      var item = (sender as ListPicker).SelectedItem;
    }
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