Programming Forums > Application Development > C++

ChiHappens · Apr 19th, 2006, 7:59 AM

HEre is a node class i just made:

public class ListNodeClass
{
private int ItemValue;
private string ItemText;
public ListNodeClass()
{
}
public ListNodeClass(int Value, string Text)
{
ItemValue = Value;
ItemText = Text;
}
public int Value
{
get
{
return ItemValue;
}
set
{
ItemValue = value;
}
}
public string Text
{
get
{
return ItemText;
}
set
{
ItemText = value;
}
}

}

and here is how you can use it:
System.Collections.ArrayList Nodes = new ArrayList();
for(int n=1;n<11;n++)
{
ListNodeClass NewNode = new ListNodeClass((n*10),"Item " + n.ToString());
Nodes.Add(NewNode);
}
lblItem->Text = ((ListNodeClass)Nodes[0]).Value.ToString();
txtItem->Text = ((ListNodeClass)Nodes[0]).Text;

Hope this helps,
Chi

InfoGeek · Apr 19th, 2006, 8:00 AM

You forgot the code tags, buddy!

DaWei · Apr 19th, 2006, 8:14 AM

Purdy, ain' it?

nnxion · Apr 19th, 2006, 8:56 AM

Quote:

Originally Posted by DaWei

Purdy, ain' it?

What's purdy mean? I can't find it in the dictionary.

Infinite Recursion · Apr 19th, 2006, 9:01 AM

Southerner's way of saying pretty.

grumpy · Apr 19th, 2006, 9:04 AM

Either that, or purdy was what Tweety called Sylvester.

Ooble · Apr 19th, 2006, 10:28 AM

ChiHappens, that's C#, not C++ .NET. There's a difference, I'm afraid.

Twilight · Apr 21st, 2006, 12:58 AM

Ok, well, I still don't have an answer to my rather simple problem. I had VC++ make me a form object, with the corresponding Form1.h file.

I then went into the main .cpp file, and tried trying to access an object on the form, namely lblTotal, a label object. I reached the current mess I have now by randomly changing things:

(Toggle Plain Text)

int main(array<System::String ^> ^args)
{
	// Enabling Windows XP visual effects before any controls are created
	Application::EnableVisualStyles();
	Application::SetCompatibleTextRenderingDefault(false); 

	// Create the main window and run it
	Application::Run(gcnew Form1());
	(Form1::lblTotal)::Label::Text::set("some text");
        // Form1::lblTotal->Text = and such also won't work.
	return 0;
}

And then I get the following errors:

(Toggle Plain Text)

.\Till Program.cpp(19) : error C2143: syntax error : missing ';' before 'System::Windows::Forms::Label::Text::set'
.\Till Program.cpp(19) : error C2597: illegal reference to non-static member 'TillProgram::Form1::lblTotal'
.\Till Program.cpp(19) : error C2352: 'System::Windows::Forms::Label::Text::set' : illegal call of non-static member function

Somebody mind telling me just how I get at form objects?

The Dark · Apr 21st, 2006, 1:26 AM

The Run method of application doesn't return until the application has finished anyway, so you can't execute code after the Run method and expect that the form is still around.
If you wanted to access the form fields from somewhere else (e.g. another form), then you could pass the form value to that other form. Something like:

(Toggle Plain Text)

	// Create the main window and run it
        Form1 ^newForm1 = gcnew Form1();
        newForm1->lblTotal->Text = "hello";
        Application::Run(newForm1);

Note that you would have to change the lblTotal field to "public" in Form1

Twilight · Apr 21st, 2006, 1:33 AM

Ah, so ok, so I just have to do all that stuff from within Form1.h. Which leads me to my next question:

Now from within Form1.h, on a certain button click, I want to read the text inside of txtItem, a standard textbox. I tried this:

(Toggle Plain Text)

txtItem->Text = "0";
string current;
current = txtItem->Text;

but got these rather long errors:

(Toggle Plain Text)

c:\documents and settings\sam\my documents\visual studio 2005\projects\till program\till program\Form1.h(469) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'System::String ^' (or there is no acceptable conversion)
        C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(875): could be 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const std::basic_string<_Elem,_Traits,_Ax> &)'
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
        C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(880): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const _Elem *)'
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
        C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(885): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(_Elem)'
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
        while trying to match the argument list '(std::string, System::String ^)'

Care to tell me how I should be doing it?

Apr 19th, 2006, 7:59 AM	#11
ChiHappens Programmer Join Date: Sep 2005 Location: Brevard, NC Posts: 35 Rep Power: 0	HEre is a node class i just made: public class ListNodeClass { private int ItemValue; private string ItemText; public ListNodeClass() { } public ListNodeClass(int Value, string Text) { ItemValue = Value; ItemText = Text; } public int Value { get { return ItemValue; } set { ItemValue = value; } } public string Text { get { return ItemText; } set { ItemText = value; } } } and here is how you can use it: System.Collections.ArrayList Nodes = new ArrayList(); for(int n=1;n<11;n++) { ListNodeClass NewNode = new ListNodeClass((n*10),"Item " + n.ToString()); Nodes.Add(NewNode); } lblItem->Text = ((ListNodeClass)Nodes[0]).Value.ToString(); txtItem->Text = ((ListNodeClass)Nodes[0]).Text; Hope this helps, Chi __________________ http://www.starshipcombatsimulator.com They mostly come at night...mostly.

Apr 19th, 2006, 8:00 AM	#12
InfoGeek Professional Programmer Join Date: Jun 2005 Location: India, The great. Posts: 435 Rep Power: 4	You forgot the code tags, buddy! __________________ PFO - My daily dose of technology.

Apr 19th, 2006, 8:14 AM	#13
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Purdy, ain' it? __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Apr 19th, 2006, 9:01 AM	#15
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,467 Rep Power: 8	Southerner's way of saying pretty. __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Apr 19th, 2006, 10:28 AM	#17
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	ChiHappens, that's C#, not C++ .NET. There's a difference, I'm afraid. __________________ Me :: You :: Them

Apr 19th, 2006, 9:04 AM	#16
grumpy Programming Guru Join Date: Jun 2005 Location: Adelaide, South Australia Posts: 1,223 Rep Power: 5	Either that, or purdy was what Tweety called Sylvester.

Apr 21st, 2006, 12:58 AM	#18
Twilight Programmer Join Date: Apr 2006 Location: Calgary, Alberta Posts: 67 Rep Power: 3	Ok, well, I still don't have an answer to my rather simple problem. I had VC++ make me a form object, with the corresponding Form1.h file. I then went into the main .cpp file, and tried trying to access an object on the form, namely lblTotal, a label object. I reached the current mess I have now by randomly changing things: (Toggle Plain Text) int main(array<System::String ^> ^args) { // Enabling Windows XP visual effects before any controls are created Application::EnableVisualStyles(); Application::SetCompatibleTextRenderingDefault(false); // Create the main window and run it Application::Run(gcnew Form1()); (Form1::lblTotal)::Label::Text::set("some text"); // Form1::lblTotal->Text = and such also won't work. return 0; } int main(array<System::String ^> ^args) { // Enabling Windows XP visual effects before any controls are created Application::EnableVisualStyles(); Application::SetCompatibleTextRenderingDefault(false); // Create the main window and run it Application::Run(gcnew Form1()); (Form1::lblTotal)::Label::Text::set("some text"); // Form1::lblTotal->Text = and such also won't work. return 0; } And then I get the following errors: (Toggle Plain Text) .\Till Program.cpp(19) : error C2143: syntax error : missing ';' before 'System::Windows::Forms::Label::Text::set' .\Till Program.cpp(19) : error C2597: illegal reference to non-static member 'TillProgram::Form1::lblTotal' .\Till Program.cpp(19) : error C2352: 'System::Windows::Forms::Label::Text::set' : illegal call of non-static member function .\Till Program.cpp(19) : error C2143: syntax error : missing ';' before 'System::Windows::Forms::Label::Text::set' .\Till Program.cpp(19) : error C2597: illegal reference to non-static member 'TillProgram::Form1::lblTotal' .\Till Program.cpp(19) : error C2352: 'System::Windows::Forms::Label::Text::set' : illegal call of non-static member function Somebody mind telling me just how I get at form objects?

Apr 21st, 2006, 1:26 AM	#19
The Dark Expert Programmer Join Date: Jun 2005 Posts: 852 Rep Power: 4	The Run method of application doesn't return until the application has finished anyway, so you can't execute code after the Run method and expect that the form is still around. If you wanted to access the form fields from somewhere else (e.g. another form), then you could pass the form value to that other form. Something like: (Toggle Plain Text) // Create the main window and run it Form1 ^newForm1 = gcnew Form1(); newForm1->lblTotal->Text = "hello"; Application::Run(newForm1); // Create the main window and run it Form1 ^newForm1 = gcnew Form1(); newForm1->lblTotal->Text = "hello"; Application::Run(newForm1); Note that you would have to change the lblTotal field to "public" in Form1

Apr 21st, 2006, 1:33 AM	#20
Twilight Programmer Join Date: Apr 2006 Location: Calgary, Alberta Posts: 67 Rep Power: 3	Ah, so ok, so I just have to do all that stuff from within Form1.h. Which leads me to my next question: Now from within Form1.h, on a certain button click, I want to read the text inside of txtItem, a standard textbox. I tried this: (Toggle Plain Text) txtItem->Text = "0"; string current; current = txtItem->Text; txtItem->Text = "0"; string current; current = txtItem->Text; but got these rather long errors: (Toggle Plain Text) c:\documents and settings\sam\my documents\visual studio 2005\projects\till program\till program\Form1.h(469) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'System::String ^' (or there is no acceptable conversion) C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(875): could be 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const std::basic_string<_Elem,_Traits,_Ax> &)' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(880): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const _Elem )' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(885): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(_Elem)' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] while trying to match the argument list '(std::string, System::String ^)' c:\documents and settings\sam\my documents\visual studio 2005\projects\till program\till program\Form1.h(469) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'System::String ^' (or there is no acceptable conversion) C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(875): could be 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const std::basic_string<_Elem,_Traits,_Ax> &)' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(880): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const _Elem )' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] C:\Program Files\Microsoft Visual Studio 8\VC\include\xstring(885): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(_Elem)' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] while trying to match the argument list '(std::string, System::String ^)' Care to tell me how I should be doing it? Last edited by Twilight; Apr 21st, 2006 at 1:45 AM.

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Programming Forums > Application Development > C++

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