I have a dll which comes from a third party, which was written in C++. Here is some information that comes from the dll documentation:
//start documentation
RECO_DATA{
wchar_t Surname[200];
wchar_t Firstname[200];
}
Description: Data structure for receiving the function result. All function result will be stored as Unicode (UTF-8).
Method:
bool recoCHN_P_Name(char *imgPath,RECO_DATA *o_data);
Input:
char * imgPath
the full path of the image location for this function to recognize
RECO_DATA * o_data
data object for receiving the function result. Function return: True if Success, otherwise false will return.
//end documentation
I am trying to call the recoCHN_P_Name from my C# application. To this end, I came up with this code:
The code to import the dll:
public class cnOCRsdk
{
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct RECO_DATA{
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=200)]
public string FirstName;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 200)]
public string Surname;
}
[DllImport(@"cnOCRsdk.dll", EntryPoint="recoCHN_P_Name")]
public static extern bool recoCHN_P_Name(byte[] imgPath, RECO_DATA o_data);
}
The code to call the function:
cnOCRsdk.RECO_DATA recoData = new cnOCRsdk.RECO_DATA();
string path = @"C:\WINDOWS\twain_32\twainrgb.bmp";
System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
byte[] bytes = encoding.GetBytes(path);
bool res = cnOCRsdk.recoCHN_P_Name(bytes, recoData);
And the error I'm getting is ""Unable to find an entry point named 'recoCHN_P_Name' in DLL 'cnOCRsdk.dll'." I'm suspecting that I'm having an error in converting a type from C++ to C#. But where exactly ... ?
