The problem to use in DLL

Question

0.00/5 (No votes)

See more:

I meet a problem in c# that use the C++ DLL.

This is the error:

Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

Any idea for this?

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct TP_ISSUE_DATA
        {
            public Byte CardType;
            public Byte IssueCount;
            public UInt32 CID;
            public UInt32 Sum;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
            public string line1;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
            public string line2;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
            public string line3;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
            public string line4;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
            public string line5;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
            public string line6;
        }
 
TP_ISSUE_DATA tpissue = new TP_ISSUE_DATA();
tpissue.CardType = 3;
tpissue.IssueCount = 1;
tpissue.CID = 1234;
tpissue.Sum = 1000;
tpissue.line1 = "Line 1";
tpissue.line2 = "Line 2";
tpissue.line3 = "Line 3";
tpissue.line4 = "Line 4";
tpissue.line5 = "Line 5";
tpissue.line6 = "Line 6";

if (TP_Open(Handle, 1) == 0)
{
    int iInite = TP_Issue(tpissue);
}

TP_ISSUE is the function in the DLL, I try want to use it, but it come out the error message.

I search from the web, got some idea for this.
The type declaration for the C++ and C# are difference so got this message and I also try to match the declaration already, still the same.

How?

Posted 24-Jul-11 23:21pm

jonaschu

Updated 25-Jul-11 3:33am

R. Giskard Reventlov

v3

Add a Solution

Comments

[no name] 25-Jul-11 5:23am

Show the source code which threw the error.

Sergey Alexandrovich Kryukov 25-Jul-11 9:59am

Not clear. Where is the C++ part, what was P/Invoked? Where the exception is thrown?
--SA

DaveyM69 25-Jul-11 14:41pm

We need to see the C++ declaration of the function and your C# P/Invoke version of it.

jonaschu 25-Jul-11 20:25pm

the problem is i don't have the c++ source..
headaches now.. the c++ source is from my supplier..

Philippe Mori 25-Jul-11 22:01pm

How would you uses it from C++. You should have an header file that would allows you to use the DLL from C++. Then you could probably do the appropriate translation.

jonaschu 26-Jul-11 21:05pm

i get the DLL only, the c++ code i use the de-essembly s/w to get it.
but i also dunno correct or not

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Max Bogon · Answer 1 · 2011-07-26T09:32:00

Solution 2

It might be the fact that C++ uses ANSII while C# uses UNICODE strings. The error you are getting would indicate an overflow condition (reading past the end of the string). Just a guess

Posted 26-Jul-11 9:32am

Max Bogon

Comments

jonaschu 26-Jul-11 21:24pm

so how to i check for this? is it any work around method?

Max Bogon 27-Jul-11 14:57pm

There is no workaround. You might try finding the TP_ISSUE_DATA struct definition in your dis-assembly. Then determine how many bytes each field is in C++; then find an appropriate C# data type (same number of bytes) and define your structure that way. You are going to have to trust your disassembled code. ANSII uses one byte per character, UNICODE uses 2 bytes per character, as a general rule. You have to watch you arithmetic data type sizes as well. Trial and error is the only way that I know of.

jonaschu 29-Jul-11 0:28am

thanks max, i try to work for this..
is really take my time..
my friend tell me maybe is the pointer problem.
im not pro in C++, bad luck