SEHException while calling dll function

Question

4.00/5 (1 vote)

See more:

Hi all,
I am calling a function in Delphi dll from C#.I am getting an exception saying
"System.Runtime.InteropServices.SEHException occurred in transliteration.exe.
Additional information:External componenet has thrown an exception".
Function signature in dll is like this:

FUNCTION foo(PASS1,PASS2 : LongInt; Astring, BString : PChar; Scrpt : LongInt) : LongInt; stdcall;EXPORT;

& corresponding signature in C# is -

public static extern int foo(Int32 pass1, Int32 pass2, string txtToConvert, StringBuilder convText, ref Int32 scriptCode);

The function is called on textbox leave event.I need to pass last parameter in C# by reference.If i don't I get an access violation exception.I surfed the internet about this exception & got to know that this is related to Application.EnableVisualStyles(); function in Program.cs (I am not sure about this.)Is it true or is there is any other solution for this?

The same function is working on my side but on client's machine its giving an exception.Machine configuration is exactly same.

Please help me.
Thanks.

Posted 27-Apr-11 18:34pm

bsaurabh

Updated 27-Apr-11 18:37pm

v3

Add a Solution

Comments

JF2015 28-Apr-11 0:36am

Improved formatting.

2 solutions

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)

Sergey Alexandrovich Kryukov · Answer 1 · 2011-04-27T18:42:00

The C# function is not corresponding to the Delphi one. How can it be StringBuilder, ever? Last parameter is not by ref but by value.

Try

C#

public static extern Int32 foo(
    Int32 pass1, Int32 pass2,
    string txtToConvert, string convText,
    Int32 scriptCode);

I'm not really sure about one of the parameters of the type PChar. If one of the parameters is meant to be output, probably both signatures are incorrect.

If last parameter should be by reference, it could be var or const in Delphi (yes, Delphi has a weird feature: const before a parameter means "constant reference", not just constant), and in C# in should be out or ref (it only depends on function implementation semantic and affects the usage by the caller).

—SA

Mahdi Ataollahi · Answer 2 · 2012-11-10T01:19:00

You must use PInvoke to use unmanaged types like PChar in .NET to call such DLLs. These links would be useful:

http://embarcadero.newsgroups.archived.at/public.delphi.nativeapi/201007/1007013727.html[^]

http://msdn.microsoft.com/de-de/library/system.runtime.interopservices.unmanagedtype.aspx[^]

SEHException while calling dll function

2 solutions

Solution 1

Solution 3

Add your solution here

Preview 0