GridImageColumn throws exception of 'Object does not match target type' when binding to an interface

[Mathew]

I have a RadGrid that's using a RadImageColumn to display an image based on the value of a field in the data source, which is working perfectly fine.

However, when my datasource is bound to a collection of an interface type, I'm getting the error "Object does not match target type".

My classes are structures as follows:

interface I
{
    string ImageURL
}
class A : I
{
    string ImageUrl { get { ... } }
}
class B : I
{
    string ImageURL { get { ... } }
}

I'm binding to a datasource that is a collection of items of type I.  What appears to be happening is that when my datasource only contains records of either type A or only records of type B, the grid binds succesfully.  The problem seems to occur when I try to bind to a datasource that contains both types, and only occurs the first time it tries to bind to the second type.  Presumably this might also cause problems with abstract classes, or other derived properties.

[Mathew]

Has anyone been able to reproduce this issue?  It's only happening with RadImageColumn, not anything else.

[Radoslav]

Hello Mathew,

Indeed I verified that the described behavior exists in the current version of our controls. However I will forward this issue to our developers for further investigation.  At a meantime you can use GridTemplateColumn with places image into its ItemTemplate.

I hope this helps.

Greetings,
Radoslav
the Telerik team

[Mathew]

Hi Radoslav, thanks for the response.  Yes, that's exactly what I'm doing to get around the issue at the moment but will look forward to it being fixed in a future release.