Different P/Invoke entry point for .NET vs .NET Core 2

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In .NET Framework and .NET Core, P/Invoke (Platform Invocation Services) allows managed code to call native functions in dynamic link libraries (DLLs). When working with P/Invoke in .NET Framework and .NET Core 2, you might encounter differences in how the entry points are specified due to the underlying platform and framework architecture.

Here's how you can handle the differences between .NET Framework and .NET Core 2 when specifying P/Invoke entry points:

  1. .NET Framework:
    In .NET Framework, the entry point specified in the DllImport attribute generally corresponds to the function name as it appears in the DLL's export table. You usually specify only the function name without any additional decorations.

    csharp
    using System.Runtime.InteropServices;

    public class NativeMethods
    {
    [DllImport("MyLibrary.dll")]
    public static extern int MyFunction();
    }
  2. .NET Core 2:
    In .NET Core 2, when working with libraries built for Windows platforms (such as Windows API libraries), you may need to include the EntryPoint parameter in the DllImport attribute to specify the exact entry point name. This is due to changes in the naming convention of exported functions in .NET Core P/Invoke.

    csharp
    using System.Runtime.InteropServices;

    public class NativeMethods
    {
    [DllImport("MyLibrary.dll", EntryPoint = "MyFunction")]
    public static extern int MyFunction();
    }

By specifying the EntryPoint parameter, you ensure that the correct function is invoked from the DLL, regardless of the differences between .NET Framework and .NET Core in handling P/Invoke entry points.

Please note that this information is applicable to .NET Core 2.x. Starting from .NET Core 3.0, the naming convention for exported functions was aligned more closely with .NET Framework, so the differences in specifying entry points between .NET Framework and .NET Core are less prominent. Always refer to the official documentation and any platform-specific guidance when working with P/Invoke in your specific context.