# Visual Studio imported interface problems
**URL:** https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359
**Category:** Hydra
**Created:** [February 4, 2025, 2:17pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359 "2025-02-04T14:17:10Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@mjtrainor](https://talk.remobjects.com/u/mjtrainor)
#### Post date: [February 4, 2025, 2:17pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/1 "2025-02-04T14:17:10Z")
As before: Registered Hydra 6.7.0.1345, Delphi 11, Visual Studio 2022 17.12.4
.NET8 with a test project created from the VS2022 wizard. Non visual plugin only
I have imported a Delphi interface to VS2022 in a Framework project, then copied the imported .cs to the .Net8 project, but there seem to be some problems. First off the import:
> // Imported cross-patform Hydra plugin interfaces
> // Some interfaces may not be imported or imported incorrectly due to the following issues:
> // [51:8] CloseRound expected
> //
>
> namespace HydraTest
> {
> [System.Runtime.InteropServices.GuidAttribute(“d372b43d-a36a-48f2-81f4-90e5008b74aa”)]
> public interface IPointCloudFilterInterface : RemObjects.Hydra.CrossPlatform.IHYCrossPlatformInterface
> {
> Integer TestValue();
> }
> }
I did some searching here but can’t figure out what the CloseRound expected message means. (During a later import while writing this message, the comment with CloseRound went away).
FYI, the comment has a a typo and says cross-patform instead of cross-platform.
Second, on Integer TestValue() Integer is unknown. I’m guess there needs to be a using, but alt-enter on Integer doesn’t give me any choices beyond creating my own type. I worked around it for now by changing it to int.
Where I’m stuck right now is I have a test C# library with the Delphi import unit in it, and I’ve created a new plugin in that library, but the Mixed Mode C# sample doesn’t show (or I can’t find where it does) how to reference the interface the import created from Delphi with the plugin, or how to create an instance of it so I can use it.
Can you give me or point me to a simple example of instancing a Delphi non-visual plugin in C#?
---
### Author:  [@EvgenyK](https://talk.remobjects.com/u/EvgenyK)
#### Post date: [February 4, 2025, 2:43pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/2 "2025-02-04T14:43:51Z")
Hi,
can you show your delphi interface, pls?
---
### Author:  [@mjtrainor](https://talk.remobjects.com/u/mjtrainor)
#### Post date: [February 4, 2025, 2:58pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/3 "2025-02-04T14:58:06Z")
```
[System.Runtime.InteropServices.GuidAttribute("d372b43d-a36a-48f2-81f4-90e5008b74aa")]
public interface IPointCloudFilterInterface : RemObjects.Hydra.CrossPlatform.IHYCrossPlatformInterface
{
int TestValue();
}
```
}
---
### Author:  [@EvgenyK](https://talk.remobjects.com/u/EvgenyK)
#### Post date: [February 4, 2025, 3:05pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/4 "2025-02-04T15:05:46Z")
> [@mjtrainor](#):
>
> ```auto
> [System.Runtime.InteropServices.GuidAttribute("d372b43d-a36a-48f2-81f4-90e5008b74aa")]
> public interface IPointCloudFilterInterface : RemObjects.Hydra.CrossPlatform.IHYCrossPlatformInterface
> {
> int TestValue();
> }
>
> ```
I mean original **delphi** interface (.pas file).
---
### Author:  [@mjtrainor](https://talk.remobjects.com/u/mjtrainor)
#### Post date: [February 4, 2025, 3:11pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/5 "2025-02-04T15:11:37Z")
[PCFInterfaces.pas](https://talk.remobjects.com/uploads/short-url/jMPF8Sxicgc7hQhrF2QvOW7G3wp.pas) (273 Bytes)
[NonVisualPlugin.pas](https://talk.remobjects.com/uploads/short-url/3hjjlSNPn3aECn99B8w6erY5Krm.pas) (1.7 KB)
[hcNPL2Controller.pas](https://talk.remobjects.com/uploads/short-url/jwAsFLy2Kef96TCqfz5h23AKL9k.pas) (2.2 KB)
---
### Author:  [@EvgenyK](https://talk.remobjects.com/u/EvgenyK)
#### Post date: [February 4, 2025, 3:25pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/6 "2025-02-04T15:25:37Z")
Hi,
> [@mjtrainor](#):
>
> // [51:8] CloseRound expected
I can’t reproduce this error
> [@mjtrainor](#):
>
> Second, on Integer TestValue() Integer is unknown. I’m guess there needs to be a using, but alt-enter on Integer doesn’t give me any choices beyond creating my own type. I worked around it for now by changing it to int.
I’ll review why it uses `Integer` instead of `int` type.
we have table that describes Delphi and .NET types at [https://docs.hydra4.com/HowTos/PassingInterfacesBetweenHostAndPlugins](https://docs.hydra4.com/HowTos/PassingInterfacesBetweenHostAndPlugins) .
> [@mjtrainor](#):
>
> Can you give me or point me to a simple example of instancing a Delphi non-visual plugin in C#?
review this sample: [testcase.zip](https://talk.remobjects.com/uploads/short-url/1oY48QFYgdkXISrtpgmWgmdzlcB.zip) (19.7 KB)
---
### Author:  [@mjtrainor](https://talk.remobjects.com/u/mjtrainor)
#### Post date: [February 4, 2025, 4:33pm UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/7 "2025-02-04T16:33:48Z")
I’ve made some progress, through searching the forums here, but I had to make changes for it to run and I’m not getting the response I should. Maybe you can assist:
```
public static class Program
{
[STAThread]
public static void Main(string[] args_)
{
var moduleManager = new ModuleManager();
var module = moduleManager.LoadModule(@"c:\temp\NPL2\Win32\Debug\NPL2.DLL");
var plugIns = moduleManager.Plugins.ToArray();
foreach (var plugin in plugIns)
{
Console.WriteLine($"{plugin.Description} {plugin.Name} {plugin.UserData}");
}
var inst = moduleManager.CreateInstance("PointCloudFilterInterfaceTest");
if (inst is IPointCloudFilterInterface test)
{
Console.WriteLine($"{test.TestValue()}");
}
}
}
```
To make it work (and maybe it’s the cause of the wrong value), I had to change the Delphi side interface to inherit from IHYCrossPlatformPlugin instead of IHYCrossPlatformInterface.
TestValue() should return 42, it’s hard coded in Delphi, but I’m getting zero.
---
### Author:  [@EvgenyK](https://talk.remobjects.com/u/EvgenyK)
#### Post date: [February 5, 2025, 7:30am UTC](https://talk.remobjects.com/t/visual-studio-imported-interface-problems/31359/8 "2025-02-05T07:30:57Z")
Hi,
> [@mjtrainor](#):
>
> TestValue() should return 42, it’s hard coded in Delphi, but I’m getting zero.
these declarations work as expected:
```auto
IPointCloudFilterInterface = interface(IHYCrossPlatformInterface)
['{D372B43D-A36A-48F2-81F4-90E5008B74AA}']
function TestValue : Integer; safecall;
end;
```
```auto
[System.Runtime.InteropServices.GuidAttribute("d372b43d-a36a-48f2-81f4-90e5008b74aa")]
public interface IPointCloudFilterInterface : RemObjects.Hydra.CrossPlatform.IHYCrossPlatformInterface
{
int TestValue();
}
```
[testcase2.zip](https://talk.remobjects.com/uploads/short-url/47D7Lh0kGakwCQapTF7pXbmueVX.zip) (19.4 KB)