I am having problems with aggregates not behaving as expected with "virtual" properties which do not exist in the type over which the aggregate function operates. The property is attached to the type using a type descriptor and redirected to an actual implementation. The Grid complains that there is no method compatible with the supplied arguments, even if the virtual property is of type int and the aggregate function does indeed exist.
This is what I believe is going on. When the grid fetches the type of the associated property to find out whether there is a function compatible with it, it gets the metadata via reflection directly instead of going through the extensible TypeDescriptor [1].
[1] - http://msdn.microsoft.com/en-us/library/ms171819.aspx
This is what I believe is going on. When the grid fetches the type of the associated property to find out whether there is a function compatible with it, it gets the metadata via reflection directly instead of going through the extensible TypeDescriptor [1].
[1] - http://msdn.microsoft.com/en-us/library/ms171819.aspx
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jose
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answered on 14 Jan 2011, 02:24 PM
I tried to work around this and failed. Let me illustrate with an example.
Suppose that I have a class C. My factory returns objects of type C, and E is the "virtual" property that I want to aggregate on. Notice that E does not exist in C. In F# :
Currently we are using the type descriptor to attach property E to C at run time, and the problem is that the grid does not check with the type descriptor when looking for a suitable aggregate function. So I tried to use an alternate design: Make the factory produce a subtype CE of C with the property E, but upcast to C before returning the object. In F# :
Unfortunately this doesn't work either, because the Grid only inspects the static type of the property and not the type of the values at runtime.
I am currently out of ideas to work around this, and time presses. The right fix is to make the Grid go through the type descriptor instead of usingdirect reflection. Would it be possible to get a hotfix ?
Thanks
Suppose that I have a class C. My factory returns objects of type C, and E is the "virtual" property that I want to aggregate on. Notice that E does not exist in C. In F# :
type C () = ...type Factory () = member makeC () : C = C()Currently we are using the type descriptor to attach property E to C at run time, and the problem is that the grid does not check with the type descriptor when looking for a suitable aggregate function. So I tried to use an alternate design: Make the factory produce a subtype CE of C with the property E, but upcast to C before returning the object. In F# :
type CE () = inherit C member this.E : int = ...type Factory () = member makeC () : C = upcast CE()Unfortunately this doesn't work either, because the Grid only inspects the static type of the property and not the type of the values at runtime.
I am currently out of ideas to work around this, and time presses. The right fix is to make the Grid go through the type descriptor instead of usingdirect reflection. Would it be possible to get a hotfix ?
Thanks
0
Accepted
Hello jose,
As my colleague already advised in the support ticket - please send us a sample project which we can debug locally.
Thank you
Greetings,
Veselin Vasilev
the Telerik team
As my colleague already advised in the support ticket - please send us a sample project which we can debug locally.
Thank you
Greetings,
Veselin Vasilev
the Telerik team
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