Newbie: Add 2 strings together

  • Thread starter Thread starter Paul Hemans
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Paul Hemans

I am trying to have a label show the X and Y positions of the mouse, but I
am getting bogged down with string handling

void MyForm::OnMouseMove(MouseEventArgs *e){

// Display the x position

string ss;

ss = e->X.ToString();

ss += " ";

ss += e->Y.ToString();

m_poLabel->Text = ss;

}



error C2679: binary '=' : no operator found which takes a right-hand operand
of type 'System::String __gc *' (or there is no acceptable conversion)



Thanks
 
Paul Hemans said:
I am trying to have a label show the X and Y positions of the mouse, but I
am getting bogged down with string handling

void MyForm::OnMouseMove(MouseEventArgs *e){

// Display the x position

string ss;

ss = e->X.ToString();

ss += " ";

ss += e->Y.ToString();

m_poLabel->Text = ss;

}



error C2679: binary '=' : no operator found which takes a right-hand
operand of type 'System::String __gc *' (or there is no acceptable
conversion)



Thanks
Click to expand...
Try something like this...

System::String^ fun = L"Done!";

fun += L" I'm a genius!";

label2->Text = fun;

Works fine here.
 
What does the ^ mean?

When I compile I get:
'^' : incompatible with '/clr:oldSyntax' command line option

How do I turn this option off?
 
I am getting :
error C2679: binary '=' : no operator found which takes a right-hand operand
of type 'System::String __gc *' (or there is no acceptable conversion)

on the line
ss = e->X.ToString();

Any ideas?
 
Paul Hemans said:
What does the ^ mean?

When I compile I get:
'^' : incompatible with '/clr:oldSyntax' command line option
Click to expand...
Perhaps I've made an invalid assumption here. The code I sent is C++/CLI in
VS 2005. If you're using an earlier version of Visual Studio, it won't work.
BTW, ^ is a handle in C++/CLI.
Please tell us which version of Visual Studio you're using.
 
pvdg42 said:
Perhaps I've made an invalid assumption here. The code I sent is C++/CLI
in VS 2005. If you're using an earlier version of Visual Studio, it won't
work.
BTW, ^ is a handle in C++/CLI.
Please tell us which version of Visual Studio you're using.
Click to expand...

VS2005, because VS2003 didn't have an oldSyntax option, it always used
oldSyntax.

The option is in the project settings -- under "Common Language Runtime
Support", try "/clr" instead of "/clr: oldSyntax".

The basic problem is while C# has a string keyword which maps to
System.String, C++/CLI does not. In C++, string is either undefined or
finds the Standard C++ library class std::string, which is not the same as a
..NET string. Use String with a capital S, no other changes to your original
program should be necessary.
 
I turned off the oldSyntax setting and the rest of the program blew up.

I have to say learning c++ is a nightmare (particularly regarding strings).

In Foxpro I would do :

label.text = trans(e.X) + " " + trans(e.Y)

I do understand that Foxpro is a high level language and that a comparison
shouldn't be made but after 2 days I still can't add a couple of strings
together it really makes you wonder. Maybe I am thick, or maybe C++ has been
reworked so many times that only gurus can make a program with it.

Can you recommend a VS2005 book that teaches this stuff well? I found one on
2003 but I am glad I didn't buy it because apparently a lot has changed
between versions.
 
Paul Hemans said:
I turned off the oldSyntax setting and the rest of the program blew up.

I have to say learning c++ is a nightmare (particularly regarding
strings).

In Foxpro I would do :

label.text = trans(e.X) + " " + trans(e.Y)

I do understand that Foxpro is a high level language and that a comparison
shouldn't be made but after 2 days I still can't add a couple of strings
together it really makes you wonder. Maybe I am thick, or maybe C++ has
been reworked so many times that only gurus can make a program with it.

Can you recommend a VS2005 book that teaches this stuff well? I found one
on 2003 but I am glad I didn't buy it because apparently a lot has changed
between versions.
Click to expand...

Here's one we've found useful for MFC and CLI.

http://he-cda.wiley.com/WileyCDA/HigherEdTitle/productCd-0764571974,courseCd-CX0400.html
 
I know this problem:
You can't define a string like this "string ss;", must be "String
*ss".


"Paul Hemans дµÀ£º
"
 
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