C＃结构传递给非托管dll函数

Question

我用C / C ++编写了下一个函数：

__ declspec（dllexport）short CiBoardInfo（canboard_t * binfo）;

宣布结构：

typedef struct {
    unsigned char brdnum;
    unsigned long hwver;
    short chip[4];
    char name[64];
    char manufact[64];
} canboard_t;

我需要在C＃中使用它，所以我试试这个：

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
    public struct canboard_t{
        public Byte brdnum;
        public UInt32 hwver;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst=4)]
        public Int16 chip;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst=64)]
        public String name;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst=64)]
        public String manufact;
    };

   class Chai
    {
        [DllImport("chai.dll")]
        public static extern Int16 CiInit();
        [DllImport("chai.dll")]
        public static extern Int16  CiBoardInfo(ref canboard_t binfo);
    }

并试着像这样使用它：

private void Form1_Load(object sender, EventArgs e)
{
    canboard_t brd = new canboard_t();
    Chai.CiInit();
    Chai.CiBoardInfo(ref brd);
    this.Text = brd.manufact + " " + brd.name;
}

当用

调用Chai.CiBoardInfo（ref brd）时它会挂起

  

System.TypeLoadException.TypeLoadException

那有什么不对？据我所知，我的C＃代码中有不正确的书面结构。但我无法找到错误的位置。

 1. ChaiVGSNAG2.exe!ChaiVGSNAG2.Program.Main() Line 18 + 0x1d bytes  
 2. [from machine code to managed]  
 3. [from managed code to machine]  
 4. mscorlib.dll!System.AppDomain.ExecuteAssembly(string assemblyFile,
    System.Security.Policy.Evidence assemblySecurity, string[] args) +
    0x6b bytes  
 5. Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
    + 0x27 bytes  
 6. mscorlib.dll!System.Threading.ThreadHelper.ThreadStart_Context(object
    state) + 0x6f bytes  
 7. mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext
    executionContext, System.Threading.ContextCallback callback, object
    state, bool preserveSyncCtx) + 0xa7 bytes  
  8. mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext
    executionContext, System.Threading.ContextCallback callback, object
    state, bool preserveSyncCtx) + 0x16 bytes  
  9. mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext
    executionContext, System.Threading.ContextCallback callback, object
    state) + 0x41 bytes  
 10. mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x44
    bytes  
 11. [from machine code to managed]