Question

如何将枚举设置为xaml中的列表框。但是在列表框中我需要显示描述而不是枚举的名称/值。然后，当我单击一个按钮时，我需要将选定的枚举通过icommand作为枚举而不是字符串传递给方法。例如：

  public enum MyEnum 
  {
     EnumOne = 0,
     [Description("Enum One")]
     EnumTwo = 1,
     [Description("Enum Two")]
     EnumTwo = 2,
     [Description("Enum Three")]
  }

需要将这些枚举绑定到具有描述的displaymemberpath的列表框。然后在列表框中进行选择后，传递所选的枚举，如下所示：

  private void ButtonDidClick(MyEnum enum)
  {

  }

XAML：

  <ListBox ItemsSource="{Binding MyEnum"} /> ?

我知道如何将命令连接到按钮等等。感谢您的帮助。

Answer 1

来自制作应用程序
很久以前得到了这个，无法找到来源将DisplayMememberPath绑定到值

public static Dictionary<T, string> EnumToDictionary<T>()
    where T : struct
{
    Type enumType = typeof(T);

    // Can't use generic type constraints on value types,
    // so have to do check like this
    if (enumType.BaseType != typeof(Enum))
        throw new ArgumentException("T must be of type System.Enum");
    Dictionary<T, string> enumDL = new Dictionary<T, string>();
    foreach (T val in Enum.GetValues(enumType))
    {
        enumDL.Add(val, val.ToString());
    }
    return enumDL;
}

GetDescription方法

对于那些想知道如何阅读description属性值的人。以下内容可以轻松转换为使用enum或扩展。我发现这种实现更灵活。

使用此方法，将val.ToString()替换为GetDescription(val)。

    /// <summary>
    /// Returns the value of the 'Description' attribute; otherwise, returns null.
    /// </summary>
    public static string GetDescription(object value)
    {
        string sResult = null;

        FieldInfo oFieldInfo = value.GetType().GetField(value.ToString());

        if (oFieldInfo != null)
        {
            object[] oCustomAttributes = oFieldInfo.GetCustomAttributes(typeof(DescriptionAttribute), true);

            if ((oCustomAttributes != null) && (oCustomAttributes.Length > 0))
            {
                sResult = ((DescriptionAttribute)oCustomAttributes[0]).Description;
            }
        }
        return sResult;
    }

Answer 2

使用ObjectDataProvider：

<ObjectDataProvider x:Key="enumValues"
   MethodName="GetValues" ObjectType="{x:Type System:Enum}">
      <ObjectDataProvider.MethodParameters>
           <x:Type TypeName="local:ExampleEnum"/>
      </ObjectDataProvider.MethodParameters>
 </ObjectDataProvider>

然后绑定到静态资源：

ItemsSource="{Binding Source={StaticResource enumValues}}"

找到此解决方案here

Answer 3

您可以通过将Enum转换为MyEnum-string元组列表并使用ListBox的DisplayMemberPath参数显示描述项来实现。当你选择一个特定的元组时，只需抓住它的MyEnum部分，并使用它来设置ViewModel中的SelectedEnumValue属性。

以下是代码：

XAML：

<Window x:Class="EnumToListBox.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition/>
        <RowDefinition/>
    </Grid.RowDefinitions>
    <ListBox Grid.Row="0" 
             ItemsSource="{Binding EnumToDescriptions}"
             SelectedItem="{Binding SelectedEnumToDescription}"
             DisplayMemberPath="Item2"/>
    <TextBlock Grid.Row="1" 
               Text="{Binding SelectedEnumToDescription.Item2}"/>
</Grid>

守则背后：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        this.DataContext = new ViewModel();
    }
}

public class ViewModel : PropertyChangedNotifier
{
    private List<Tuple<MyEnum, string>> _enumToDescriptions = new List<Tuple<MyEnum, string>>();
    private Tuple<MyEnum, string> _selectedEnumToDescription;

    public ViewModel()
    {
        Array Values = Enum.GetValues(typeof(MyEnum));
        foreach (var Value in Values)
        {
            var attributes = Value.GetType().GetField(Value.ToString()).GetCustomAttributes(typeof(DescriptionAttribute), false);
            var attribute = attributes[0] as DescriptionAttribute;
            _enumToDescriptions.Add(new Tuple<MyEnum, string>((MyEnum)Value, (string)attribute.Description));
        }
    }

    public List<Tuple<MyEnum, string>> EnumToDescriptions
    {
        get
        {
            return _enumToDescriptions;
        }
        set
        {
            _enumToDescriptions = value;
            OnPropertyChanged("EnumToDescriptions");
        }
    }

    public Tuple<MyEnum, string> SelectedEnumToDescription
    {
        get
        {
            return _selectedEnumToDescription;
        }
        set
        {
            _selectedEnumToDescription = value;
            SelectedEnumValue = _selectedEnumToDescription.Item1;
            OnPropertyChanged("SelectedEnumToDescription");
        }
    }

    private MyEnum? _selectedEnumValue;
    public MyEnum? SelectedEnumValue
    {
        get
        {
            return _selectedEnumValue;
        }
        set
        {
            _selectedEnumValue = value;
            OnPropertyChanged("SelectedEnumValue");
        }
    }
}

public enum MyEnum
{
    [Description("Item1Description")]
    Item1,
    [Description("Item2Description")]
    Item2,
    [Description("Item3Description")]
    Item3,
    [Description("Item4Description")]
    Item4
}

public class PropertyChangedNotifier : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    public void OnPropertyChanged(string propertyName)
    {
        var propertyChanged = PropertyChanged;
        if (propertyChanged != null)
        {
            propertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

如何将Enum设置为ItemsSource WPF

3 个答案:

GetDescription方法