Generic type in DataType of WPF's DataTemplate

Asked Sep 08 '18 at 20:47

Active Sep 08 '18 at 21:03

Viewed 641 times

Consider a public class LogItem and a derived generic class LogItem<T> as shown below. After some wasted time searching for the correct syntax to specify the generic type in XAML, the editor was finally happy. Yet I got the error below trying to build the project. I am using VS 2017 Preview but I am guessing VS 2017 would barf just the same. If I omit the (system:Int32) part, everything goes as planned. I am using NET 4.6.2.

error MC3050: Cannot find the type 'modules:LogItem(system:Int32)'. Note that type names are case sensitive.

namespace App.Modules
{
    public class LogItem
    {
        public string Info { get; set; }
    }

    public class LogItem<T> : LogItem
    {
        public T Content { get; set; }
    }
}

    xmlns:modules="clr-namespace:App.Modules"
    xmlns:system="clr-namespace:System;assembly=mscorlib"

    <DataTemplate DataType="{x:Type modules:LogItem(system:Int32)}">

edited Sep 08 '18 at 21:03

asked Sep 08 '18 at 20:47

wpfwannabe

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Can we see your `xmlns` declarations? Also, which version of .NET are you using? – laptou Sep 08 '18 at 20:55
@laptou Sure. I've updated the question. – wpfwannabe Sep 08 '18 at 21:03
Is your XAML in the same assembly as the type you are trying to reference? – laptou Sep 08 '18 at 21:04
Very much so. Not just that but also in the very same namespace. – wpfwannabe Sep 08 '18 at 21:08
Does it work if you write ``modules:LogItem`1`` instead? – laptou Sep 08 '18 at 21:10
The app builds but that does not produce the desired result, does it? Suppose I want to have two templates based on different generic params. – wpfwannabe Sep 08 '18 at 21:14
Not sure if this syntax is valid for `x:Type`. I only found mention of it in the `x:TypeArguments` documentation. – Clemens Sep 08 '18 at 21:14
Not sure either. I found reference to it here: https://stackoverflow.com/a/50711368/275449 – wpfwannabe Sep 08 '18 at 21:27
Which also does not compile. – Clemens Sep 08 '18 at 21:42
Yeah. And when I try to write my own custom `MarkupExtension`, I get a nasty surprise with `error MC3012: A key for a dictionary cannot be of type ... Only String, TypeExtension, and StaticExtension...` – wpfwannabe Sep 08 '18 at 21:51
Crazy as it seems but I might have to go with this suggestion: https://stackoverflow.com/a/2360065/275449 – wpfwannabe Sep 08 '18 at 21:52

Generic type in DataType of WPF's DataTemplate

0 Answers0