Announcements
Attention for Customers without Multi-Factor Authentication or Single Sign-On - OTP Verification rolls out April 2025. Read all about it here.

Hi @ChristianAhlers.  I am not familiar with writing code in C#.net, but I can follow your code OK, due to how similar it is to vb.net.  I just checked on the Form.ShowDialog official documentation website (link below), and it says that this applies to .NET Framework 4.8.1 and other versions.  It does not mention regular .NET, so I can only assume that it will no longer work with the newer system being used in Inventor 2025, since they stepped forward to using regular .NET.

https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.form.showdialog 

Same for the DialogResult Enum..., because it is .NET Framework 4.8.1 (and earlier), and Windows Desktop 9 and earlier.

https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.dialogresult 

I will be interested in seeing the next best alternatives myself, because I still use that method in several of the solutions where I work.

Edit:  The System.Windows.Forms.Form object is the same way.  I am not sure if the whole System.Windows.Froms Namespace is only supported in those code systems listed above or not.

Wesley Crihfield

EESignature

(Not an Autodesk Employee)