MvvmCross不能从绑定声明猜枚举类型 - 所以它不能执行此结合

在这个最简单的路线可能是解决这一使用字符串！而非 - 然后你就需要使用 Enum.Parse 从字符串到您的视图模型的枚举。

另一种方法是，您还可以实现一个枚举解析ValueConverter刚刚解析字符串 - 例如你可以立足于https://github.com/MvvmCross/MvvmCross/blob/v3.1/Cirrious/Cirrious.MvvmCross.Binding/ValueConverters/MvxCommandParameterValueConverter.cs - 您可以添加 Enum.Parse 来此创建：

 公共类MyEnumCommandValueConverter    ：MvxValueConverter＆LT; ICommand的，ICommand的＆GT;{    保护覆盖的ICommand转换（ICommand的价值，System.Type的TARGETTYPE，对象参数，System.Globalization.CultureInfo文化）    {        返回新MvxWrappingCommand（值，Enum.Parse（typeof运算（MyEnum），parameter.ToString（）））;    }} 

然后，您可以使用绑定嵌套 - 使用类似：

 地方：MvxBind =点击MyEnumCommand（MyCommand，'两'） 

I want to pass an enum value as a CommandParameter. My enum is defined as:

public enum MyEnum
{
   One,
   Two
}

And in my axml I have:

local:MvxBind="Click MyCommand, CommandParameter=MyEnum.One"
...
local:MvxBind="Click MyCommand, CommandParameter=MyEnum.Two"

and MyCommand is defined in my ViewModel as

public IMvxCommand MyCommand
{
  get { return new MvxCommand<MyEnum>(myfunction); }
}

private void myfunction(MyEnum p_enumParam)
{
  switch (p_enumParam)
  {
      case MyEnum.One:
          doSomething1();
          break;
      case MyEnum.Two:
          doSomething2();
          break;
  }
}

When I run it, I get the error "System.InvalidCastException: Cannot cast from source type to destination type."

Obviously, because it cannot cast MyEnum.One and MyEnum.Two to the MyEnum type. So how can I convince it that MyEnum.One and MyEnum.Two are of MyEnum type?

Thanks, Pap

MvvmCross can't guess the type of enum from the binding statement - so it can't perform this binding.

The easiest route on this is probably to workaround this using strings instead - and you will then need to use Enum.Parse from the string to the enum in your ViewModel.

An alternative is that you could also implement an enum parsing ValueConverter which just parsed the string - e.g. you could base on https://github.com/MvvmCross/MvvmCross/blob/v3.1/Cirrious/Cirrious.MvvmCross.Binding/ValueConverters/MvxCommandParameterValueConverter.cs - you could add Enum.Parse to this to create:

public class MyEnumCommandValueConverter
    : MvxValueConverter<ICommand, ICommand>
{
    protected override ICommand Convert(ICommand value, System.Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return new MvxWrappingCommand(value, Enum.Parse(typeof(MyEnum), parameter.ToString()));
    }
}

You could then bind using nesting - using something like:

local:MvxBind="Click MyEnumCommand(MyCommand, 'Two')"