Compile and Register C# Code

The compileCsharp interface is used to compile C# source code and return a unique function ID (funid) for subsequent calls.

Interface Description

Interface Type

compileCsharp

Parameters

Parameter	Type	Required	Description
code	string	✅	C# source code string
refs	string[]	❌	Array of managed DLL file paths

Return Value

Returns a string type funid (function ID), used for subsequent calls to this function via the executeCsharp interface.

Basic Usage

Simple Example

// Compile and register a simple C# function
const funid = await apiInvoke("compileCsharp", {
    code: `
        using System;
        using System.Collections.Generic;
        using System.Runtime.InteropServices;
        using System.Threading.Tasks;
        using OpenCvSharp;
        
        // Load unmanaged DLL
        public static class User32
        {
            [DllImport("user32.dll")]
            public static extern int MessageBox(IntPtr hWnd, string text, string caption, uint type);
        }

        public class Startup
        {
            public async Task<object> Invoke(dynamic args)
            {
                // Get parameters
                byte[] screenShotImage = (byte[])args.screenshot;
                int inta = (int)args.inta;
                float floatb = (float)args.floatb;

                User32.MessageBox(IntPtr.Zero, "OpenCvSharp and user32 are loaded", "Notice", 0);
                //......

                return inta + floatb;
            }
        }
    `,
    // Only managed DLL files are allowed here
    refs: ["D:\\opencv\\OpenCvSharp.dll"]
})

console.log('funid', funid)
// Output: Function ID: abc123def456...

Notes

⚠️ Important Limitations

1. Managed DLL Limitation

   • The refs parameter can only reference managed DLLs (.NET assemblies)
   • For unmanaged DLLs, use DllImport

2. Fixed Class and Method Names

   • Class name must be Startup
   • Method name must be Invoke
   • Signature must be public async Task<object> Invoke(dynamic args)

3. Namespace References

   • Must explicitly reference required namespaces (e.g., using System;)
   • Does not automatically reference all namespaces

Compilation Error Handling

If compilation fails, the interface will throw an exception.

Next Steps

After compilation, use the returned funid to call the function:

See Execute C# Function to learn how to call compiled functions.