函數調用導致堆棧不對稱。原因可能是托管的 PInvoke 簽名與非托管的目標簽名不匹配。在dllimport中加入CallingConvention參數就行了.還要加上CharSet = CharSet.Auto。

[DllImport("Dogskin.dll",EntryPoint ="Encode", CharSet = CharSet.Auto, CallingConvention = CallingConvention.Cdecl)]
public static extern StringBuilder Encode(string passWord);

要註意C++與NET中數據類型的對應：

//c++:char * ---- c#:string //傳入參數
//c++:char * ---- c#:StringBuilder//傳出參數
//c++:char *變量名 ---- c#:ref string 變量名
//c++:char *輸入變量名 ---- c#:string 輸入變量名
//c++:char *輸出變量名 ---- c#:[MarshalAs(UnmanagedType.LPStr)] StringBuilder 輸出變量名

//c++:SHORT(short) ---- c#:System.Int16

//c++:LONG(long) ---- c#:System.Int32

轉載收集：

//C#調用C++的DLL搜集整理的所有數據類型轉換方式,可能會有重復或者多種方案,自己多測試
//c++:HANDLE(void *) ---- c#:System.IntPtr
//c++:Byte(unsigned char) ---- c#:System.Byte
//c++:SHORT(short) ---- c#:System.Int16
//c++:WORD(unsigned short) ---- c#:System.UInt16
//c++:INT(int) ---- c#:System.Int16
//c++:INT(int) ---- c#:System.Int32
//c++:UINT(unsigned int) ---- c#:System.UInt16
//c++:UINT(unsigned int) ---- c#:System.UInt32
//c++:LONG(long) ---- c#:System.Int32
//c++:ULONG(unsigned long) ---- c#:System.UInt32
//c++:DWORD(unsigned long) ---- c#:System.UInt32
//c++:DECIMAL ---- c#:System.Decimal
//c++:BOOL(long) ---- c#:System.Boolean
//c++:CHAR(char) ---- c#:System.Char
//c++:LPSTR(char *) ---- c#:System.String
//c++:LPWSTR(wchar_t *) ---- c#:System.String
//c++:LPCSTR(const char *) ---- c#:System.String
//c++:LPCWSTR(const wchar_t *) ---- c#:System.String
//c++:PCAHR(char *) ---- c#:System.String
//c++:BSTR ---- c#:System.String
//c++:FLOAT(float) ---- c#:System.Single
//c++:DOUBLE(double) ---- c#:System.Double
//c++:VARIANT ---- c#:System.Object
//c++:PBYTE(byte *) ---- c#:System.Byte[]


//c++:BSTR ---- c#:StringBuilder
//c++:LPCTSTR ---- c#:StringBuilder
//c++:LPCTSTR ---- c#:string
//c++:LPTSTR ---- c#:[MarshalAs(UnmanagedType.LPTStr)] string
//c++:LPTSTR 輸出變量名 ---- c#:StringBuilder 輸出變量名
//c++:LPCWSTR ---- c#:IntPtr
//c++:BOOL ---- c#:bool
//c++:HMODULE ---- c#:IntPtr
//c++:HINSTANCE ---- c#:IntPtr
//c++:結構體 ---- c#:public struct 結構體{};
//c++:結構體 **變量名 ---- c#:out 變量名 //C#中提前申明一個結構體實例化後的變量名
//c++:結構體 &變量名 ---- c#:ref 結構體 變量名



//c++:WORD ---- c#:ushort
//c++:DWORD ---- c#:uint
//c++:DWORD ---- c#:int


//c++:UCHAR ---- c#:int
//c++:UCHAR ---- c#:byte
//c++:UCHAR* ---- c#:string
//c++:UCHAR* ---- c#:IntPtr


//c++:GUID ---- c#:Guid
//c++:Handle ---- c#:IntPtr
//c++:HWND ---- c#:IntPtr
//c++:DWORD ---- c#:int
//c++:COLORREF ---- c#:uint


//c++:unsigned char ---- c#:byte
//c++:unsigned char * ---- c#:ref byte
//c++:unsigned char * ---- c#:[MarshalAs(UnmanagedType.LPArray)] byte[]
//c++:unsigned char * ---- c#:[MarshalAs(UnmanagedType.LPArray)] Intptr


//c++:unsigned char & ---- c#:ref byte
//c++:unsigned char 變量名 ---- c#:byte 變量名
//c++:unsigned short 變量名 ---- c#:ushort 變量名
//c++:unsigned int 變量名 ---- c#:uint 變量名
//c++:unsigned long 變量名 ---- c#:ulong 變量名


//c++:char 變量名 ---- c#:byte 變量名 //C++中一個字符用一個字節表示,C#中一個字符用兩個字節表示
//c++:char 數組名[數組大小] ---- c#:MarshalAs(UnmanagedType.ByValTStr, SizeConst = 數組大小)] public string 數組名; ushort


//c++:char * ---- c#:string //傳入參數
//c++:char * ---- c#:StringBuilder//傳出參數
//c++:char *變量名 ---- c#:ref string 變量名
//c++:char *輸入變量名 ---- c#:string 輸入變量名
//c++:char *輸出變量名 ---- c#:[MarshalAs(UnmanagedType.LPStr)] StringBuilder 輸出變量名


//c++:char ** ---- c#:string
//c++:char **變量名 ---- c#:ref string 變量名
//c++:const char * ---- c#:string
//c++:char[] ---- c#:string
//c++:char 變量名[數組大小] ---- c#:[MarshalAs(UnmanagedType.ByValTStr,SizeConst=數組大小)] public string 變量名;


//c++:struct 結構體名 *變量名 ---- c#:ref 結構體名 變量名
//c++:委托 變量名 ---- c#:委托 變量名


//c++:int ---- c#:int
//c++:int ---- c#:ref int
//c++:int & ---- c#:ref int
//c++:int * ---- c#:ref int //C#中調用前需定義int 變量名 = 0;

//c++:*int ---- c#:IntPtr
//c++:int32 PIPTR * ---- c#:int32[]
//c++:float PIPTR * ---- c#:float[]


//c++:double** 數組名 ---- c#:ref double 數組名
//c++:double*[] 數組名 ---- c#:ref double 數組名
//c++:long ---- c#:int
//c++:ulong ---- c#:int

//c++:UINT8 * ---- c#:ref byte //C#中調用前需定義byte 變量名 = new byte();


//c++:handle ---- c#:IntPtr
//c++:hwnd ---- c#:IntPtr

//c++:void * ---- c#:IntPtr
//c++:void * user_obj_param ---- c#:IntPtr user_obj_param
//c++:void * 對象名稱 ---- c#:([MarshalAs(UnmanagedType.AsAny)]Object 對象名稱


//c++:char, INT8, SBYTE, CHAR ---- c#:System.SByte
//c++:short, short int, INT16, SHORT ---- c#:System.Int16
//c++:int, long, long int, INT32, LONG32, BOOL , INT ---- c#:System.Int32
//c++:__int64, INT64, LONGLONG ---- c#:System.Int64
//c++:unsigned char, UINT8, UCHAR , BYTE ---- c#:System.Byte
//c++:unsigned short, UINT16, USHORT, WORD, ATOM, WCHAR , __wchar_t ---- c#:System.UInt16
//c++:unsigned, unsigned int, UINT32, ULONG32, DWORD32, ULONG, DWORD, UINT ---- c#:System.UInt32
//c++:unsigned __int64, UINT64, DWORDLONG, ULONGLONG ---- c#:System.UInt64
//c++:float, FLOAT ---- c#:System.Single
//c++:double, long double, DOUBLE ---- c#:System.Double

//Win32 Types ---- CLR Type


//Struct需要在C#裏重新定義一個Struct
//CallBack回調函數需要封裝在一個委托裏，delegate static extern int FunCallBack(string str);

//unsigned char** ppImage替換成IntPtr ppImage
//int& nWidth替換成ref int nWidth
//int*, int&, 則都可用 ref int 對應
//雙針指類型參數，可以用 ref IntPtr
//函數指針使用c++: typedef double (*fun_type1)(double); 對應 c#:public delegate double fun_type1(double);
//char* 的操作c++: char*; 對應 c#:StringBuilder;
//c#中使用指針:在需要使用指針的地方 加 unsafe

//unsigned char對應public byte
/*
* typedef void (*CALLBACKFUN1W)(wchar_t*, void* pArg);
* typedef void (*CALLBACKFUN1A)(char*, void* pArg);
* bool BIOPRINT_SENSOR_API dllFun1(CALLBACKFUN1 pCallbackFun1, void* pArg);
* 調用方式為
* [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
* public delegate void CallbackFunc1([MarshalAs(UnmanagedType.LPWStr)] StringBuilder strName, IntPtr pArg);
*
*
*/

Dogskin.dll方法Encode(char* str)用C#調用的問題