How to include a DLL used within a Class Library in C# Interactive

[shaggygi]

Version Used: Visual Studio 2019 16.8 Preview 1

This is more of a question, but seems to be an issue.

I have a .NET 4.7.2 Class Library that depends on a native DLL in same location that uses DllImport to call methods. I tried right-clicking the project in Solution Explorer and selecting "Initialize Interactive with Project" and is loaded in C# Interactive. However, when calling methods that call the DllImport methods within, it appears to throw errors like it can't find/load the native DLL.

"System.DllNotFoundException: Unable to load DLL 'xxx.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)"

I can use the Class Library project with no problems in a WPF or Console app.

How can I make sure the native DLL is located in the required location when using my Class Library project in C# Interactive and in script files (csx)?

Any help is appreciated.

[tmat]

native DLL in same location that uses DllImport to call methods.

Are the two dlls in the same directory? How does the DllImport look like?

[shaggygi]

Are the two dlls in the same directory? How does the DllImport look like?

Yes, they get copied to the bin/Debug folder when built.

Example of a method.

[DllImport("device.dll")]
private static extern int Device_Open(int portNumber, string baudRate);

public static void Open(int portNumber, string baudRate)
{
    Device_Open(portNumber, baudRate);
}