对于带有FlagsAttribute的枚举类型,最常见的解决方案是为枚举的所有项和所选项在您的VM中使用特定字段。可以像这样:
XAML
<Window.DataContext>
<local:MainWindowViewModel />
</Window.DataContext>
<Grid>
<xctkpg:PropertyGrid Grid.Row="1" SelectedObject="" AutoGenerateProperties="False">
<xctkpg:PropertyGrid.EditorDefinitions>
<xctkpg:EditorTemplateDefinition TargetProperties="">
<xctkpg:EditorTemplateDefinition.EditingTemplate>
<DataTemplate>
<xctk:CheckComboBox ItemsSource="" SelectedValue="" />
</DataTemplate>
</xctkpg:EditorTemplateDefinition.EditingTemplate>
</xctkpg:EditorTemplateDefinition>
</xctkpg:PropertyGrid.EditorDefinitions>
<xctkpg:PropertyGrid.PropertyDefinitions>
<xctkpg:PropertyDefinition TargetProperties="Value" />
</xctkpg:PropertyGrid.PropertyDefinitions>
</xctkpg:PropertyGrid>
</Grid>
C#
class MainWindowViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private ItemViewModel _currentObject = new ItemViewModel() { Value = TestEnum.Test3 | TestEnum.Test7 };
public ItemViewModel CurrentObject
{
get { return _currentObject; }
set
{
_currentObject = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(CurrentObject)));
}
}
}
public class ItemViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private TestEnum _value;
public TestEnum Value
{
get { return _value; }
set
{
_value = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Value)));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(SelValue)));
}
}
public string SelValue
{
get
{
return String.Join(",", Enum.GetValues(typeof(TestEnum)).OfType<TestEnum>().Where(v => (_value & v) != 0).Select(v => v.ToString()));
}
set
{
_value = value.Split(new[] { ','}, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Trim()).
Aggregate((TestEnum)0, (acc, val) => acc | (TestEnum)Enum.Parse(typeof(TestEnum), val));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(SelValue)));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Value)));
}
}
public ObservableCollection<string> Items
{
get
{
return new ObservableCollection<string>(Enum.GetNames(typeof(TestEnum)));
}
}
}
更新于2016年1月31日
为使代码能够用于动态生成的枚举类型,我进行了以下更改:
XAML
<xctkpg:EditorTemplateDefinition TargetProperties="Value">
C#
public class ItemViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public static readonly Type EnumType = GenerateEnumType();
private object _value;
public object Value
{
get { return _value; }
set
{
_value = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Value)));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(SelValue)));
}
}
public string SelValue
{
get
{
return String.Join(",",
Enum.GetValues(EnumType).OfType<object>().Where(v => ((int)_value & (int)v) != 0).Select(v => v.ToString()));
}
set
{
var strings = value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Trim());
_value = Enum.ToObject(EnumType, strings.Aggregate(0, (acc, val) => acc | (int)Enum.Parse(EnumType, val)));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(SelValue)));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Value)));
}
}
public ObservableCollection<string> Items
{
get
{
return new ObservableCollection<string>(Enum.GetNames(EnumType));
}
}
public static Type GenerateEnumType()
{
string asmNameString = "flags_enum";
AppDomain appDomain = AppDomain.CurrentDomain;
AssemblyName asmName = new AssemblyName(asmNameString);
AssemblyBuilder asmBuilder = appDomain.DefineDynamicAssembly(asmName, AssemblyBuilderAccess.Run);
ModuleBuilder modBuilder = asmBuilder.DefineDynamicModule(asmNameString + "_module");
EnumBuilder enumBuilder = modBuilder.DefineEnum(asmNameString, TypeAttributes.Public, typeof(int));
Type fa = typeof(FlagsAttribute);
CustomAttributeBuilder attributeBuilder =
new CustomAttributeBuilder(fa.GetConstructor(new Type[0]), new object[0]);
enumBuilder.SetCustomAttribute(attributeBuilder);
for (int i = 0; i < 7; i++)
{
enumBuilder.DefineLiteral($"Test{i + 1}", 1 << i);
}
return enumBuilder.CreateType();
}
}
现在对于ItemViewModel,可以像这样设置值:
ItemViewModel vm = new ItemViewModel();
vm.Value = Enum.ToObject(ItemViewModel.EnumType, 33);
[EnumBuilder](https://msdn.microsoft.com/de-de/library/system.reflection.emit.enumbuilder%28v=vs.110%29.aspx)
动态创建一个Enum
。 - Franz Wimmer