Trying to use the UnmanagedCallersOnly attribute but I'm stuck on some string fields in the structure. Is it possible to model this structure that is usable with the new UnmanagedCallersOnly attribute?

试图使用UnmanagedCallersOnly属性，但我被结构中的一些字符串字段卡住了。是否可以对可与新的UnmanagedCallersOnly属性一起使用的结构进行建模？

C++ structure:

struct PluginInfo {
        int     nStructSize;   
        int     nType;         
        int     nVersion;      
        char    szName[ 64 ];  
        char    szVendor[ 64 ];
};

I'm getting stuck on converting the szName and szVendor to c#.

我一直在把szName和szVendor转换成c#。

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct PluginInfo
{
    public int StructSize;

    [MarshalAs(UnmanagedType.I4)]
    public PluginType Type; // PluginType is an enumeration

    public int Version;

    [MarshalAs(UnmanagedType.LPWStr, SizeConst = 64)] //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 64)]
    public string Name;

    [MarshalAs(UnmanagedType.LPWStr, SizeConst = 64)] //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 64)]
    public string Vendor;
}


public class Plugin
{
    [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvCdecl) })]
    public static void GetPluginInfo(ref PluginInfo pluginInfo)
    {

        pluginInfo.Name = "myPluginName";
        pluginInfo.Vendor = "myVendorName";
        pluginInfo.Type = PluginType.Data;
        pluginInfo.StructSize = Marshal.SizeOf((PluginInfo)pluginInfo);

    }
}

The error is "Cannot use 'PluginInfo' as a parameter type on a method attributed with 'UnmanagedCallersOnly'"

错误为“无法将'PluginInfo'用作具有'UnmanagedCallersOnly'属性的方法的参数类型”

using System;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

unsafe struct PluginInfo
{
    public int nStructSize;
    public int nType;   
    public int nVersion;
    // fixed means in place buffer, like in your C++ declaration
    public fixed char szName[64];
    public fixed char szVendor[64];
};

class d{
    [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvCdecl) })]
    unsafe public static void GetPluginInfo(PluginInfo* info)
    {
        // PluginInfo required to be blittable, so we can use sizeof directly
        Debug.Assert(Marshal.SizeOf<PluginInfo>() == sizeof(PluginInfo));
        info->nStructSize = sizeof(PluginInfo);

        // use Span
        var s = new Span<char>(info->szName, 64);
        "hello".CopyTo(s);
        s["hello".Length] = '\0'; // it's `sz`, so null terminator is required
        
        // or use pointer directly
        info->szName[0] = 'x';
    }

    unsafe static void Main()
    {
        delegate* unmanaged[Cdecl]<PluginInfo*, void> callback = &GetPluginInfo;

        PluginInfo inf = default; // zero initializedd, unless SkipLocalsInit applied
        callback(&inf);
        
        // copy to string
        var name = new string(inf.szName/*, 0, 64 - 1*/);
        // or use [ReadOnly]Span
        var name2 = MemoryMarshal.CreateReadOnlySpanFromNullTerminated(inf.szName);
        
        Console.WriteLine(name);
        Console.WriteLine(name2.SequenceEqual(name));
        Console.WriteLine(name2.SequenceEqual("xello"));
        Console.WriteLine(inf.nStructSize == (64 + 64) * sizeof(char) + sizeof(int) * 3);
    }
}