XAML Serialization bug

Question

Hi all,

I have this class

public class XamlBugClass
{
    List<string> myList = new List<string>();
    public List<string> MyList
    {
        get { return myList; }
        set { myList = value; }
    }
}

this XAML

<XamlBugClass xmlns="clr-namespace:WindowsFormsApplication1;assembly=WindowsFormsApplication1" >
    <XamlBugClass.MyList>
        <String xmlns="clr-namespace:System;assembly=mscorlib" >hello world</String>
        <String xmlns="clr-namespace:System;assembly=mscorlib" >hello world2</String>
    </XamlBugClass.MyList>
</XamlBugClass>

and I do this operation

object t = XamlReader.Load(File.OpenRead("MySample.xaml"));
string XAML = XamlWriter.Save(t);

The Load just works perfect but when I get to the Save I get

"Cannot serialize a generic type 'System.Collections.Generic.List`1[System.String]'."

 

This does not make sense at all, so I consider it a bug.

Cheers,

Tobias

Answer 1

Hi Tobias,

WPF 3.X didn't really support generics correctly so that's why you're seeing this error.  We're in the process of adding better generics support to XAML (loose XAML in System.Xaml supports it but the BAML compiler doesnt').

If you're just serializing data types and not WPF objects, you can use XamlServices.Load/Save in System.Xaml.dll in .NET 4 to serialize this.  I just tried serializing your XAML and I got:

<XamlBugClass xmlns="clr-namespace:ConsoleApplication25;assembly=ConsoleApplication25" xmlns:scg="clr-namespace:System.Collections.Generic;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <XamlBugClass.MyList>
    <scg:List x:TypeArguments="x:String" Capacity="4">
      <x:String>hello world</x:String>
      <x:String>hello world2</x:String>
    </scg:List>
  </XamlBugClass.MyList>
</XamlBugClass>

- Mike

Answer 2

Hi all,

I have this class

this XAML

and I do this operation

The Load just works perfect but when I get to the Save I get

"Cannot serialize a generic type 'System.Collections.Generic.List`1[System.String]'."

 

This does not make sense at all, so I consider it a bug.

Cheers,

Tobias

If you're sure it's a bug, You may tell the developing team.

Answer 3

It has already been fixed in .Net 4 .

Answer 4

No, it hasn't.

In case you are familiar with using the "DelegateCommand" class for encapsulating command logic in MVVM - otherwise google on the web for implementation, I have just tried serializing an XAML which had bound commands like DelegateCommand<string> to its command properties. XamlWriter would throw that very same exception.

Still looking for a workaround ever since.

C.

 

Answer 5

Is there any solutions about this problem?