delphi记录到C#

Question

需要帮助将delphi记录转换为C#struct并将此结构传递给C dll:

type Transaction = record
  pos_id: array[0..9] of char;
  ev_type: array[0..4] of char;
  amount: array[0..14] of char;
  chip_reader_used: boolean;
  internal_magstripereader_used: boolean;
  track2data: array[0..99] of char;
  card_usage_mode: array[0..4] of char;
  receipt_directory: array[0..254] of char;
  additional_info: array[0..999] of char;
  event_number: array[0..9] of char;
  original_filingcode: array[0..19] of char;
  transaction_reasoncode: array[0..9] of char;
end;

试过以下但没有工作:

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
public unsafe struct Transaction {
        public fixed byte pos_id[10];
        public fixed byte ev_type[5];
        public fixed byte amount[15];
        public bool       chip_reader_used;
        public bool       internal_magstripereader_used;
        public fixed byte track2data[100];
        public fixed byte card_usage_mode[5];
        public fixed byte receipt_directory[255];
        public fixed byte additional_info[1000];
        public fixed byte event_number[10];
        public fixed byte original_filingcode[20];
        public fixed byte transaction_reasoncode[10];
};

和C函数是:

void Card_Event(struct)

C#(由GetProcAddress加载)

[UnmanagedFunctionPointer(CallingConvention.StdCall)]
private delegate void Card_Event_Func(ref Transaction transaction);

IntPtr procAddr = GetProcAddress(_hDLL, "Card_Event");
if ( procAddr == IntPtr.Zero )
    return false;
Card_Event_Func Card_Event = (Card_Event_Func)Marshal.GetDelegateForFunctionPointer(procAddr, typeof(Card_Event_Func));

Answer 1

你应该UnmanagedType.ByValTStr用于字符串.这里不需要不安全的代码.你会发现下面的声明,使用字符串,比不安全的固定数组更容易使用.

请注意,您还需要为布尔值指定单字节编组.默认编组bool是BOOL与Win32 API函数兼容的4字节.

最后,我不确定你为什么选择打包记录.Delphi代码中没有任何迹象表明它已被打包.

所以,最终的翻译看起来像这样:

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct Transaction 
{
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)]
    public string pos_id;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 5)]
    public string ev_type;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 15)]
    public string amount;

    [MarshalAs(UnmanagedType.I1)]
    public bool chip_reader_used;

    [MarshalAs(UnmanagedType.I1)]
    public bool internal_magstripereader_used;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]
    public string track2data;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 5)]
    public string card_usage_mode;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 255)]
    public string receipt_directory;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 1000)]
    public string additional_info;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)]
    public string event_number;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 20)]
    public string original_filingcode;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)]
    public string transaction_reasoncode;
};

我不确定你是否正确转换了函数调用,因为你没有显示函数的函数本机代码声明.