.net - 从ListBox SelectedItems属性检索枚举

Question

我定义了一个Enum，我的意图是在列表框中向用户显示四个选项(无，左，中和右)。该列表框将允许多个选择。单击save命令时，我必须将选择传递给ViewModel，在这里我将聚合选择并将其传递给WCF服务。

枚举:

[DataContract]
[Flags]
public enum Locations
{
    None = 0,
    [EnumMember]
    Left = 1,
    [EnumMember]
    Center = 2,
    [EnumMember]
    Right = 4,
    [EnumMember]
    LeftCenter = Left | Center,
    [EnumMember]
    LeftRight = Left | Right,
    [EnumMember]
    CenterRight = Center | Right,
    [EnumMember]
    All = Left | Center | Right
}

XAML:

<Button Command="{Binding SaveCommand}"
        CommandParameter="{Binding SelectedItems, ElementName=lbLocations}" />
<ListBox x:Name="lbLocations" SelectionMode="Multiple">
    <ListBoxItem Content="{x:Static m:Subsections.None}" />
    <ListBoxItem Content="{x:Static m:Subsections.Left}" />
    <ListBoxItem Content="{x:Static m:Subsections.Center}" />
    <ListBoxItem Content="{x:Static m:Subsections.Right}" />
</ListBox>

ViewModel:

public ICommand SaveCommand
{
    get
    {
        if (_saveCommand == null)
            _saveCommand = new RelayCommand<IList>(x => Save(x));

         return _saveCommand;
    }
}

private void Save(IList locations)
{
    try
    {
        // ToList() produces InvalidCastException.
        var collection = locations.Cast<Locations>().ToList();

        // Do WCF stuff, display success, etc.
    }
    catch (Exception ex)
    {
        _dialogService.Show(ex.Message, "Error");
    }
}

我已经成功将选择内容作为IList传递回了ViewModel，但是我很难将其强制返回给我的枚举。有没有我忽略的更好的方法，这行得通吗？好像我快到了。

Answer 1

尝试遍历转换列表并将该值聚合到一个变量中，如下所示:

private void Save(IList locations)
{
    try
    {
        Locations location = Locations.None;

        foreach (Locations value in locations.Cast<Locations>())
        {
            location |= value;
        }

        // Do WCF stuff, display success, etc.
    }
    catch (Exception ex)
    {
        _dialogService.Show(ex.Message, "Error");
    }
}