Question

我将值绑定到列表中的combobox。它列出了一到五个数字。现在我想以数字格式显示所选数字。表示当用户从combobox中选择“四”时，combobox的所选项应显示为数字形式“4”。 UWP有可能吗？

List<Item> available_Nums = new List<Item>();
        available_Nums.Add(new Item { Number = 1, Text = "One" });
        available_Nums.Add(new Item { Number = 2, Text = "Two" });
        available_Nums.Add(new Item { Number = 3, Text = "Three" });
        available_Nums.Add(new Item { Number = 4, Text = "Four" });
        available_Nums.Add(new Item { Number = 5, Text = "Five" });
        ComboBox2.ItemsSource = available_Nums;

  private void ComboBox2_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        ComboBox2.SelectedItem = (ComboBox2.SelectedItem as Item).Number;
    }
 <ComboBox  x:Name="ComboBox2" SelectionChanged="ComboBox2_SelectionChanged"    Grid.Row="0"  Grid.ColumnSpan="2" HorizontalAlignment="Left">
            <ComboBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock x:Name="comboTextBox" Text="{Binding Text}" />
                </DataTemplate>
            </ComboBox.ItemTemplate>
        </ComboBox>

Answer 1

您可以使用DataTemplate执行此操作。

您可以实施ValueConverter将单词转换为数字并使用它：

<ComboBox>
   <ComboBox.ItemTemplate>
      <DataTemplate>
         <TextBlock Text="{Binding Converter={StaticResource TextToNumberConverter}}" />
      </DataTemplate>
   </ComboBox.ItemTemplate>
</ComboBox>

更好的解决方案是创建一个同时具有string和int属性的类并绑定到它而不是简单的字符串，然后使用int属性DataTemplate }

public class Item
{
   public int Number {get;set;} 
   public string Text {get;set;} 
}

创建以下项目：

new Item() {Number =1, Text="One"}

DataTemplate将是：

<DataTemplate>
        <TextBlock Text="{Binding Text}" />
</DataTemplate>

并检索所选值：

(comboBox.SelectedItem as Item).Number

Answer 2

实际上我建议使用适用于WPF的解决方案，你可以参考这个thread。

在UWP中我们只需要一些简单的修改然后它就可以了。以下是完整的代码：

首先，XAML代码：

 <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Grid.Resources>
        <DataTemplate x:Key="selectedTemplate">
            <TextBlock Text="{Binding Path=Number}"/>
        </DataTemplate>
        <DataTemplate x:Key="dropDownTemplate">
            <TextBlock Text="{Binding Path=Text}"/>
        </DataTemplate>
        <local:ComboBoxItemTemplateSelector
                x:Key="itemTemplateSelector"
        SelectedTemplate="{StaticResource selectedTemplate}"
        DropDownTemplate="{StaticResource dropDownTemplate}"/>
    </Grid.Resources>
    <ComboBox ItemTemplateSelector="{StaticResource itemTemplateSelector}" x:Name="combobox1" HorizontalAlignment="Left"  Margin="372,432,0,0" Width="200" VerticalAlignment="Top"/>
</Grid>

然后代码背后：

的MainPage：

 public sealed partial class MainPage : Page
{
    public MainPage()
    {
        this.InitializeComponent();

        List<Item> available_Nums = new List<Item>();
        available_Nums.Add(new Item { Number = 1, Text = "One" });
        available_Nums.Add(new Item { Number = 2, Text = "Two" });
        available_Nums.Add(new Item { Number = 3, Text = "Three" });
        available_Nums.Add(new Item { Number = 4, Text = "Four" });
        available_Nums.Add(new Item { Number = 5, Text = "Five" });
        combobox1.ItemsSource = available_Nums;   
    }


}


public class Item
{
    public int Number { get; set; }
    public string Text { get; set; }
}

ComboBoxItemTemplateSelector类：

public class ComboBoxItemTemplateSelector:DataTemplateSelector
{
    public DataTemplate DropDownTemplate
    {
        get;
        set;
    }
    public DataTemplate SelectedTemplate
    {
        get;
        set;
    }
    protected override DataTemplate SelectTemplateCore(object item, DependencyObject container)
    {
        ComboBoxItem comBoxItem = GetParent<ComboBoxItem>(container);
        if (comBoxItem != null)
        {
            return DropDownTemplate;
        }
        return SelectedTemplate;

    }

   internal static T GetParent<T>(object childobject) where T:DependencyObject
    {
        DependencyObject child = childobject as DependencyObject;
        while ((child != null) && !(child is T))
        {
            child = VisualTreeHelper.GetParent(child);
        }
        return child as T;
    }
}

更改ComboBox所选项目的文本 - UWP

2 个答案: