FAQs – WPF Visual Studio

WPF Properties Edit Ellipses Missing in VS 2022
Visual Studio 2022 design time properties no longer support custom property editors for WPF applications.  Use Visual Studio 2019 to develop WPF applications. The free Community Edition of Visual Studio 2019 can be download from https://visualstudio.microsoft.com/vs/older-downloads/. WinForm applications are still well supported in Visual Studio 2022.
Bad Data Quality in .NET Application.
Below are some possible reasons your .NET application is not able to read OAS tag values.

Data Source Quality

Use Configure-Tags to verify that the data quality of the source tags is "Good Quality". Menu Configure Tags
Quality Good


The Default security group on either the local or remote OAS Engine may have Disable All Tags from Reading checked under the Read Tags Tab.  See Restrict Tag Access of Security setup to see how read, write, and browse access can be restricted. View how to Implement User Credentials in Client Applications to provide log in method for each user in the .NET application.


.NET applications can be defined to communicate to remote OAS Engines.  See Network Communications Troubleshooting to verify that port 58727 is allowing both incoming and outgoing traffic through your firewall.

Tag Path

The full tag path would include the full tag name including its parent groups and the variable of the Tag.
Tag names are case sensitive and the current value of a tag would be .Value as the most common variable.
If the tag is from a remote OAS Engine see Basic Networking for standard remote tag syntax or Live Data Cloud Networking if the OAS Engine system has a dynamic IP address.


Use Configure-License to verify that a product feature .NET Data Connector, WinForm HMI, or WPF HMI is enabled on the data source system where the tags are located. Menu Configure License
Enabled Products

Target Framework for WPF and WinForm Applications

The project type for WinForm and WPF applications should be set to include (.NET Framework) and target .NET Framework 4.6.1 or greater. WinForm Target Framework See the correct project type for WinForm above that is listed as Windows Forms App (.NET Framework) while Windows Forms App would not be the correct project type.

Assembly References

Visual Studio on some operating systems will assign a legacy assembly to the project causing an incompatibility due to an older version of the reference assembly.  A common assembly that can be incorrect is Newtonsoft.Json that has been registered in the GAC by another software product. Select Newtonsoft.Json under the Project References to verify the correct path and version as
Newtonsoft.Json Assembly Reference If the Path does not reference the OAS installation directory remove the reference and select to Add Reference and browse for dll from the respective directory for the specific product feature. For .NET Framework applications include the .dlls located in C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\. The Target Framework set for the VS project must be .NET Framework 4.6.1 or greater. For .NET Standard supporting the following targets include the. dlls located in C:\Program Files\Open Automation Software\OAS\Controls\NetStandard\. See a list of locations for the correct type in the troubleshooting type After updating to OAS Version 17 the project no longer compiles for a list of correct project reference paths for each type of Visual Studio Project.

.NET Assembly is Blocked

If you have copied an application or project to another computer you may need to Unblock one or more the .dll files. Right click on the .dll file that you have downloaded. Check the Unblock checkbox for security as shown in the example below, then click Apply or OK. Excel Add-In

Legacy .NET Application with OAS Version 17

 If the OAS .NET assemblies are from OAS version 16 or less contact support@oasiot.com for compatibility instructions.
Tag Browse in Visual Studio Missing
Microsoft Visual Studio 2022 no longer supports custom property editors to browse for tags. Use Visual Studio 2019 to develop WPF applications. The free Community Edition of Visual Studio 2019 can be download from https://visualstudio.microsoft.com/vs/older-downloads/. If you prefer Visual Studio 2022 with WPF application development use the OAS Excel Tag browser to browse for the full tag path of a remote or local tag and copy the full tag path from the Tag field and paste into the desired Tag property in Visual Studio.
After updating to OAS Version 17 the project no longer compiles
OAS version 17 implements an improved network interface which requires some additional assemblies. All dependent .dlls are located in the relative subdirectory of the Controls directory of the OAS installation directory, typically C:\Program Files\Open Automation Software\OAS\Controls\. To add a reference to a Visual Studio project right click on References in the Solution Explorer. Add Reference Select Browse to browse the directory for each application feature. Browse Assemblies Include all .dlls files in the respective directory for the specific product feature. For .NET Framework applications include the .dlls located in C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\. The Target Framework set for the VS project must be .NET Framework 4.6.1 or greater. For .NET Standard supporting the following targets include the. dlls located in C:\Program Files\Open Automation Software\OAS\Controls\NetStandard\.
  • .NET 6
  • .NET 5
  • .NET Core 2.0 or greater
  • .NET Framework 4.61 or greater
  • Xamarin.iOS 10.14 or greater
  • Xamarin.Android 8.0 or greater
  • UWP or greater
WPF HMI Assemblies
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCWPFDashboard\
WinForm HMI Assemblies
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCControls\
Alarm .NET Assemblies
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCAlarmControl\
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCAlarmDataOnly\
  • C:\Program Files\Open Automation Software\OAS\Controls\NetStandard\OASAlarms\
Trend .NET Assemblies
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCTrendControl\
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCTrendDataOnly\
  • C:\Program Files\Open Automation Software\OAS\Controls\NetStandard\OASTrends\
.NET Data Connector Assemblies
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCSystemsDataConnector\
  • C:\Program Files\Open Automation Software\OAS\Controls\NetStandard\OASData\
Server Configuration Assemblies
  • C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\OPCSystems\
  • C:\Program Files\Open Automation Software\OAS\Controls\NetStandard\OASConfig\
Can WPF applications be deployed to remote systems for Internet communications?
Yes, applications communicate using WCF over a standard TCP port which is adjustable. The default port number is 58724. View the Networking – LAN, WAN, and Internet Videos on how to implement standard communications over the Internet and also the Live Data Cloud networking on how to host your own data without a fixed IP address or registered domain name.
The .NET controls do not appear in the Toolbox after selecting to add them to the Toolbox.
If you right click Toolbox and Choose to Add Items and select the OPCWPFDashboard controls, yet they do not appear in the Toolbox you may have installed Visual Studio after Open Automation Software.  If so uninstall Open Automation Software and reinstall it.  It will then register correctly with Visual Studio for adding the controls.
After updating Open Automation Software with the incremental update the project no longer compiles or the application no longer works.
Make sure to Unblock the dlls before copying to C:\Program Files\Open Automation Software\OAS\Controls\NetFramework\ or C:\Program Files\Open Automation Software\OAS\Controls\NetStandard\.
To Unblock the files copy to a trusted location for your system, Desktop works well, then right click on the file and select Properties to select Unblock. Then copy from your Desktop to the correct directory in C:\Program Files\Open Automation Software\OAS\Controls\.
My OPCWPFDashboard Button flashes when the user hovers the mouse over the button.
This is default for a WPF Button control, but the behavior can be changed with the following steps using Expression Blend.
  1. Select the button, and right click on the button, select Edit Template-Edit a Copy.  Select OK.
  2. With the new template selected reset the RenderMouseOver, and RenderPressed property.
  3. Select Triggers, and delete the IsKeyboardFocused trigger.
  4. Apply the new template to all buttons.  Select the button, right click, and select Edit Template-Apply Resource.
I want to have my HMI application automatically scale in size when the user changes the size of the application or it is run on different PC with different screen resolution.
Use a ViewBox in the Window XAML code. When you create a WPF application by default the first container in the window is a Grid. Each container has an opening and closing statement in the XAML file. For example:
<Window x:Class="MainWindow"
Title="MainWindow" Height="350" Width="525">

All of your content will be in the grid. To create a window with resizable content add a ViewBox to the window and put the grid in the ViewBox. Example:
<Window x:Class="MainWindow"
Title="MainWindow" Height="350" Width="525">

Select the view box and set the stretch property the way you want the application to respond. The options are None, Fill, Uniform and Uniform to Fill. The default is uniform.
I get a thread exit message in Visual Studio 2013.
The thread exit message is a bug in Visual Studio 2013. https://connect.microsoft.com/VisualStudio/feedback/details/812144/vs2013-reports-incorrect-thread-exit-code Check to see if you have CTP 5 installed for up to date fixes. http://www.visualstudio.com/news/vs2013-update5
How do I implement Data Binding from an Open Automation Software Tag Value?
Use the OPCWPFContent control.  Following is an example:
<Slider Height=""41"" HorizontalAlignment=""Left"" Margin=""70,190,0,0"" Name=""Slider1"" VerticalAlignment=""Top"" Width=""421"" Maximum=""100""
Value=""{Binding Content, ElementName=OPCWPFContent1}"" />
<my:OPCWPFContentControl x:Name=""OPCWPFContent1""  Height=""27"" Margin=""222,104,287,0"" VerticalAlignment=""Top""
ToolTipBadQualityText=""0"" ContentBadQualityText=""0"" Content_Tag=""Ramp.Value""/>

I receive an error stating that the Microsoft.Expression.Drawing.dll and Microsoft.Expression.Effects.dll is missing and not found.
These assemblies are included in the installation directory of Open Automation Software and can be included as a Reference in your project as local copy. Or you can install the Blend SDK from the following link that also includes these files. http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=75e13d71-7c53-4382-9592-6c07c6a00207
What assemblies do I need to deploy with my application?
Include the following in References as Local Copy:
  • C1.Win.C1FlexGrid2.dll
  • Microsoft.Expression.Drawing.dll
  • Microsoft.Expression.Effects.dll
  • Microsoft.Expression.Interactions.dll
  • Nevron.Chart.dll
  • Nevron.Chart.WinForm.dll
  • Nevron.GraphicsGL.dll
  • Nevron.Presentation.dll
  • Nevron.System.dll
  • OPCAlarmControl.dll
  • OPCSystemsInterface.dll
  • OPCTrendControl.dll
  • OPCWPFDashboard.dll