绑定枚举到MVVM光RelayCommand <T> CommandParameter

Question

我试图在XAML命令参数绑定为一个RelayCommand <MessageTokens>如下，其中MessageTokens是一个枚举

public ICommand OpenInvoiceWindowCommand 
     { 
      get 
      { 
       return _openInvoiceWindowCommand ?? 
         (_openInvoiceWindowCommand = new RelayCommand<MessageTokens>(OpenInvoiceWindow, prm => CanExecuteOpenInvoiceWindowCommand)); 
      } 
     } 

的XAML是：

<Controls1:RadMenuItem Command="{Binding SupplierInvoiceViewModel.OpenInvoiceWindowCommand}" CommandParameter="{Binding Source={x:Type ShipmentDetails:DebitInvoiceViewModelBase}, Path=MessageTokens.SupplierInvoice}" Header="Register a supplier's invoice"/> 

使用Telerik的RadGridView代码崩溃与

 
    at GalaSoft.MvvmLight.Command.RelayCommand`1.CanExecute(Object parameter) 
    at Telerik.Windows.Controls.RadMenuItem.CanExecuteApply() in c:\Builds\WPF_Scrum\HotFix_2010_Q3\Sources\Development\Controls\Navigation\Menu\RadMenuItem.cs:line 2105 
    at Telerik.Windows.Controls.RadMenuItem.ChangeCommand(ICommand oldCommand, ICommand newCommand) in c:\Builds\WPF_Scrum\HotFix_2010_Q3\Sources\Development\Controls\Navigation\Menu\RadMenuItem.cs:line 2124 
    at Telerik.Windows.Controls.RadMenuItem.OnCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) in c:\Builds\WPF_Scrum\HotFix_2010_Q3\Sources\Development\Controls\Navigation\Menu\RadMenuItem.cs:line 1623 
    at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) 
    at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) 
    at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) 
    at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType) 

等

如果我将参数更改为RelayCommand <string>而不是RelayCommand <MessageTokens>代码运行良好。

我不喜欢这样做，因为我失去了强烈输入我的参数的所有好处。

我怀疑我没有在XAML中正确声明枚举。我试过

CommandParameter = "<fullpath>..MessageTokens.SupplierInvoice>" 

但在MVVMLight中给出了InvalidCastException。

有没有人有任何建议？

非常感谢 杰里米

编辑与解决方案

的问题是，因为我没有正确指在CommandParameter内部类的+号绑定。

正确的XAML应该是：

<Controls1:RadMenuItem Command="{Binding SalesInvoiceViewModel.OpenInvoiceWindowCommand}" CommandParameter="{x:Static local:DebitInvoiceViewModelBase+MessageTokens.SalesInvoice}" Header="Raise a sales invoice"/> 

Answer 1

您可能wnat来看看这篇文章解释了如何通过一个枚举值作为commandparameter：Passing an enum value as command parameter from XAML。