c# - 如何将 ComboBox 绑定(bind)到 DataTemplate 中的所有枚举类型？

Question

我想根据绑定(bind)类型显示一个框架 UI 元素。对于枚举类型，我想显示 ComboBox。

我已经在 xaml 中包含了这部分:

<StackPanel Grid.Column="2">
   <StackPanel.Resources>

       <ObjectDataProvider x:Key="EnumValues" ObjectType="{x:Type sys:Enum}" MethodName="GetValues">
            <ObjectDataProvider.MethodParameters>
                 <x:Type TypeName= <-- How to indicate for all enum types? --> >
            </ObjectDataProvider.MethodParameters>
       </ObjectDataProvider>

       <DataTemplate DataType="{x:Type sys:String}">
            <TextBox Text="{Binding Content, RelativeSource={RelativeSource AncestorType=ContentPresenter}, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Width="100" HorizontalAlignment="Left" VerticalAlignment="Center" BorderThickness="0" />
       </DataTemplate>
       <DataTemplate DataType="{x:Type sys:Double}">
            <TextBox Text="{Binding Content, RelativeSource={RelativeSource AncestorType=ContentPresenter}, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Width="100" HorizontalAlignment="Left" VerticalAlignment="Center" BorderThickness="0"/>
       </DataTemplate>
       <DataTemplate DataType="{x:Type sys:Enum}">
            <ComboBox ItemsSource="{Binding Source={StaticResource EnumValues}}"  SelectedValue="{Binding Content, RelativeSource={RelativeSource AncestorType=ContentPresenter}, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Width="100" HorizontalAlignment="Left" VerticalAlignment="Center" BorderThickness="0"/>
       </DataTemplate>

   </StackPanel.Resources>
   <ContentPresenter Content="{Binding Value, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" />
</StackPanel>

有没有办法在 xaml 上做到这一点？

更新:目前，我使用 2 个转换器解决了它。第一个返回 ItemsSource 的给定枚举中的字符串集合:

    /// <summary>
    /// Converts the given value into a collection of strings
    /// </summary>
    /// <returns>collection of strings</returns>
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value != null)
        {
            IEnumerable<Enum> enumsCollection = value.GetType().GetEnumValues().Cast<Enum>();
            return enumsCollection.Select(enumValue => enumValue.ToString());
        }
        return null;
    }

对于 SelectedValue，第二个将枚举转换为字符串，反之亦然:

public class EnumToStringConverter : IValueConverter
    {
        #region Properties

        /// <summary>
        /// Last target type to be converted
        /// </summary>
        protected Type LastTargetType { get; set; }

        #endregion

        #region IValueConverter Members

        /// <summary>
        /// Converts a given value into a string representation
        /// </summary>
        /// <returns>string</returns>
        public object Convert(object value, System.Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value != null)
            {
                LastTargetType = value.GetType();
                return value.ToString();
            }

            return null;
        }

        /// <summary>
        /// Converts back a given value into an enum representation
        /// </summary>
        /// <returns>enum</returns>
        public object ConvertBack(object value, System.Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            return Enum.Parse(LastTargetType, value.ToString());
        }

        #endregion
    }

XAML 中的 ComboBox 定义如下:

                                    <DataTemplate DataType="{x:Type sys:Enum}">
                                        <ComboBox Name="EnumComboBox" ItemsSource="{Binding Content, RelativeSource={RelativeSource AncestorType=ContentPresenter}, Converter={StaticResource EnumValuesConv}, Mode=OneTime}"  SelectedValue="{Binding Content, Converter={StaticResource EnumToStringConv}, RelativeSource={RelativeSource AncestorType=ContentPresenter}, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Focusable="False" Width="100" Background="Transparent" HorizontalAlignment="Left" VerticalAlignment="Center" BorderThickness="0">
                                            <ComboBox.ItemTemplate>
                                                <DataTemplate>
                                                    <TextBlock Text="{Binding}"/>
                                                </DataTemplate>
                                            </ComboBox.ItemTemplate>
                                        </ComboBox>
                                    </DataTemplate>

Answer 1

请看这个:

  <Window.Resources>
    <ObjectDataProvider MethodName="GetValues"
                        ObjectType="{x:Type sys:Enum}"
                        x:Key="AlignmentValues">
      <ObjectDataProvider.MethodParameters>
        <x:Type TypeName="HorizontalAlignment" />
      </ObjectDataProvider.MethodParameters>
    </ObjectDataProvider>
  </Window.Resources>

顺便说一句，谷歌是你的 friend 。在此处发帖之前，请务必先询问谷歌。

我在发布答案之前也这样做了，我为您找到了这个链接

http://msdn.microsoft.com/en-us/library/bb613576.aspx