C# Runtime

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1.Overview

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Use Cases

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Scenarios Suitable for C# Runtime:

• 🧮 Algorithm Computation - Execute compute-intensive algorithms (such as image processing, data analysis)
• 📦 Third-party Library Integration - Call existing .NET libraries (such as OpenCV、YOLO operations, etc.)

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Ready to Use

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🔧 Powerful Ecosystem

• Access .NET Class Libraries - Can use the entire .NET Framework/Core class library
• NuGet Package Support - Can reference and use third-party libraries from NuGet

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⚡ High-Performance Hybrid Programming

• Best Practice Combination - Can leverage C# to handle compute-intensive tasks
• In-Process Calling - C# code is compiled before running, with extremely low call overhead
• Async Support - Full support for async/await, fully utilizing asynchronous performance advantages

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2.Register Code

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Compile and Register C# Code

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Endpoint Description

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Endpoint Type

compileCsharp

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Parameters

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Response Payload

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Basic Usage

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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...

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Notes

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⚠️ 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

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Compilation Error Handling

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Next Steps

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3.Execute Code

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Execute C# Function

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Endpoint Description

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Endpoint Type

executeCsharp

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Parameters

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Response Payload

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Basic Usage

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Complete Flow Example

// 1. Function ID obtained from compilation
const funid = 'XXXXX';

// 2. Execute function
const result = await apiInvoke("executeCsharp", {
    funid: funid,
    args: {
        inta: 10,
        floatb: 18.8,
        // Can reference magic parameter variables
        screenshot: "$.screenshot('deviceId')"
    }
});

console.log('Execution result:', result);

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Magic Parameter Variables

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Available Magic Variables

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Notes

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⚠️ Important Notes

1. Magic Variable Usage Rules
   • Magic variables must be passed as strings (e.g., "$.screenshot('id')")
   • Magic variables are automatically parsed to actual data before execution
2. funid Validity
   • funid is valid during application runtime
   • Needs to be recompiled after application restart
3. Parameter Type Matching
   • Parameter types must match types in C#
   • Pay attention to numeric type precision issues
4. Memory Management
   • Promptly release unmanaged resources in C#, release related resources after task processing
   • Fatal code defects may cause iClick to crash