C++ 和 C# 类型转换

using System.Runtime.InteropServices;

C++	C#	备注
HANDLE (void*)	System.IntPtr	[UnmanagedFunctionPointer(CallingConvention.Cdecl)] public delegate void MethodCallBack(int param1, int param2);
BYTE (unsigned char)	System.Byte
SHORT (short)	System.Int16
WORD (unsigned short)	System.UInt16
INT (int)	System.Int16	Int32
UINT (unsigned int)	System.Int16	Int32
LONG (long)	System.Int32
ULONG (unsigned long)	System.UINT32
DWORD (unsigned long)	System.UINT32
DECIMAL	System.Decimal
BOOL (long)	System.Boolean
CHAR (char)	System.Char
LPSTR (char*) LPWSTR (wchar_t*) LPCSTR (const char*) LPCWSTR (const wchar_t*) PCHAR (char*) BSTR	System.String	不修改字符串内容，只传参的，用string 需要修改并传出使用的，用StringBuilder+MarshalAs [DllImport("XXX.dll", CallingConvention = CallingConvention.Cdecl)], 特殊情况还需要加 DllImport.CharSet=Unicode
unsigned char*	[MarshalAs(UnmanagedType.LPArray)] byte[]	string, StringBuilder, [MarshalAs(UnmanagedType.LPArray)] IntPtr,
FLOAT (float)	System.Single
DOUBLE (double)	System.Double
VARINT	System.Object
PBYTE (byte*)	System.Byte[]
SIZE_T	System.UINT64

更复杂的C++转C#，可以使用　P/Invoke Interop Assistant 或者 查看p-invoke.net

C#调用C++

int Method(unsigned char* data, float param1, float& param2);

[DllImport("XXXLib.dll")]
public static extern int Method([MarshalAs(UnmanagedType.LPArray)] byte[] data, float parm1, out float param2);

回调函数

typedef void(*FuncCallback)(int id, bool bComplete);

[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
public delegate void FuncCallback(int param1, bool param2);
// 声明
private static FuncCallback _callbak = new FuncCallback(CallBackMethod);
// 实现
public static void CallBackMethod(int param1, int param2)
{
    // TODO
}