CustomControl TargetType does not match type of element throws error in WPF designer

Sudharsan Narayanan 1

Hi,

I have created a custom control in WPF. While working with that custom control in WPF designer, it is throwing "TargetType does not match the type of element" in the designer. But I'm getting a visual studio designer exception using the WPF Controls library. Styles are in another project and the ResourceDictionary is Merged in app.xaml.

I have also noticed that the issue only happens when selecting x64 as the active solution platform as opposed to the default Any CPU, but this also means that I have to switch change from x64 when running in Debug mode.

Hui Liu-MSFT 40,666 Reputation points Microsoft Vendor

2021-08-26T05:49:15.47+00:00

Hi,@ SudharsanNarayanan-9560. Could you show me the code of your CustomControl? What is the Platform target of your CustomControl? And what is the code of your TextBoxStyle2?
Sudharsan Narayanan 1 Reputation point

2021-08-26T06:21:43.177+00:00

Hi @Hui Liu-MSFT ,

Thanks for the update,

My sample code: https://1drv.ms/u/s!Ar1ZZ5lsIm1TcJuqPEfPvrWcQZc?e=OLNKr0

Regards,
Sudharsan
Hui Liu-MSFT 40,666 Reputation points Microsoft Vendor

2021-08-26T08:27:16.697+00:00

I did not reproduce your problem, I got the following display with your code.

For projects that target ARM or X64 processors, Visual Studio cannot run project code in the designer. (Quoting from Note in document To disable project code in the designer)
Please try the following if it works for you. If you have any questions, please let me know.
You could set the Platform of WpfApp1(Custom Control) to AnyCPU( Click Configuration Manager... under the Build menu).

Then the designer can display normally.
Sudharsan Narayanan 1 Reputation point

2021-09-01T12:14:39.77+00:00

Hi HuiLiu-MSFT,

Thanks for the update,

we're still having problems with my sample after modifying the setting in Configuration Manager.

So could you please check again my sample in Visual Studio 2019, not in the Preview version? as well as once you've opened my project in VS2019. Simply clean and build the Solution.

Then You can see the designer error.
Hui Liu-MSFT 40,666 Reputation points Microsoft Vendor

2021-09-02T06:08:29.923+00:00

Hi,@ SudharsanNarayanan-9560. What is your version of VisualStudio2019? I use VisualStudio2019 (Enterprise Version 16.10.2) to directly rebuild and run your project. It works well and below is the result graph.
Sudharsan Narayanan 1 Reputation point

2021-09-02T09:52:52.157+00:00

Hi HuiLiu-MSFT,

Thanks for the update,

I used Microsoft Visual Studio Professional 2019

Version: 16.10.4

Thanks,
Sudharsan
Hui Liu-MSFT 40,666 Reputation points Microsoft Vendor

2021-09-09T05:40:13.437+00:00

Hi,@ SudharsanNarayanan-9560. I downloaded and installed Microsoft Visual Studio Professional 2019 (Version 16.11.2) for testing. You could try to update your visual studio.
After cleaning and building the solution, the result is displayed as shown in the figure.

I set the Platform of WpfApp1(Custom Control) to AnyCPU and rebuild it.

Then the designer can display normally.
Sudharsan Narayanan 1 Reputation point

2021-09-14T16:43:09.967+00:00

Hi HuiLiu-MSFT,

Thanks for the reply,

We are still experiencing the same issue in our sample after updating VS 2019 to version 16.11.2. The video of the duplicate issue is included below. Please see the video below for further information.

Video: https://1drv.ms/u/s!Ar1ZZ5lsIm1Tct6b7lrykXFgi6I?e=vPiFfK

Thanks in advance,
Sudharsan
Hui Liu-MSFT 40,666 Reputation points Microsoft Vendor

2021-09-16T07:52:12.533+00:00
Hi,@ SudharsanNarayanan-9560.
I used the following two codes in Styles.xaml to test and did not reproduce your problem.
The code in video:

<Style x:Key="TextBoxStyle2" TargetType="{x:Type loc:CustomControl}"> ... </Style>

The code in the compressed package:

<Style x:Key="TextBoxStyle2" TargetType="{x:Type TextBox}"> ... </Style>

For this question, I recommend that you could report an issue in Developer Community.
Sudharsan Narayanan 1 Reputation point

2021-09-24T07:22:46.227+00:00

Hi @Hui Liu-MSFT ,

Thanks for the reply,

We will create a report on an issue in the Developer Community.

Thanks,
Sudharsan