Passing CSring pointer as dll function argument

Question

5.00/5 (3 votes)

See more:

Hi All,
I spend Last 45 days to deal with dll i got lots of advantages of dll for my big project management.
As Well as in every 2 Hours I got new milestone problem.

--------------------------------------------------------------------------------
Problem :-
I used dll function with _descpsec(dllexport)Which work greate,
Now lets consider following scenerio,

A function called TwoString()Normal dll function that fill strings in dll.

extern "C" __descspec(dllexport)void WINAPI TwoString(CString* First,CString* Second)
{
   Cstring tempstr,tempstr1;
   tempstr="SANTOSH";
   First=&tempstr;
   tempstr1="DHANAWADE";
   Second=&tempstr1;
}

This dll function works greate now,
As i passed the pointer as function argument then string of that pointer must be updated.

Lets take following function call

CString Name,Surname;
Name="";
Surname="";
TwoString(&Name,&Surname);

As I thing values of Name and Surname should change after DLL Called.

but Not Changed.
I have try:
1)I doesn't want implement structure or StringArray for return value.
2)Function can return only one values.
3)When i debug program pointers of Name And Surname not changed untill
First=&tempstr;
Statement.
____________________________________________________________________
All related helps,Links,codeblocks,suggestions are welcome.

Posted 22-Mar-11 20:26pm

santosh dhanawade

Updated 23-Mar-11 0:10am

v3

Add a Solution

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)

Richard MacCutchan · Accepted Answer · 2011-03-22T23:02:00

Solution 1

Try (i.e remove the addressof operators):

Cstring tempstr,tempstr1;
tempstr = "SANTOSH";
*First = tempstr;
tempstr1 = "DHANAWADE";
*Second = tempstr1;

Alternatively use references rather than pointers.

[edit]Added Carlo's fixes.[/edit]

Posted 22-Mar-11 23:02pm

Richard MacCutchan

Updated 23-Mar-11 0:36am

v2

Comments

[no name] 23-Mar-11 5:16am

How i can assign refernce to pointer

Richard MacCutchan 23-Mar-11 6:38am

You don't; you use the reference operator in your calling code and in the dll you treat the parameters as objects rather than pointers. Check your C++ notes for more detail.

CPallini 23-Mar-11 6:14am

Richard you forgot a couple of stars. Alternatively stars forgot you... :-)

Richard MacCutchan 23-Mar-11 6:36am

Thank you, not enough coffee this morning.

CPallini · Accepted Answer · 2011-03-23T00:15:00

Solution 2

*First = "SANTOSH";
*Second = "DHANAWADE";

Posted 23-Mar-11 0:15am

CPallini