Function writing with Borland Builder C++

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January 2nd, 2004, 06:51 PM

jake8

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Function writing with Borland Builder C++

I wish to write a function that does not activated by a component e.g. a
button.
The function is to be called when a button is called.
What is the best way to reference this function?
A portion of the code appears below

Code:


void __fastcall TForm1:Draw_tableClick(TObject *Sender)
{

nw();
switch (corner) {
case 'A': break;
case 'B': break;
case 'C': break;
case 'D': break;
default: break;
}

}

nw() and corner are declared in the header file. nw() is written in the main
unit.

Jake

__________________
Thanks............Jake

May 31st, 2004, 06:38 AM

Canderel

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Hi jake.

Quote:

What do you mean by 'a button is called'? Does this mean a keyboard button, or a visual button?

Now, if I understand you correctly... you'd like to respond to a button (keyboard press), and do certain things accordingly.

switch (keyboardinput) {
case 'A'
etc...

You should check your control's events. There is (most of the time) an 'OnButtonPress" event. Doubleclick on that.

Then write your code. The variable Key that is sent up is the one that you will use to see what happens.

If you don't want the component to get the Key, change it to NULL before you end the method.

You can assign the same code to all the different components at designtime.

June 1st, 2004, 04:44 AM

jake8

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Hi,
Thanks for your response.
What I am trying to find out is how to write a function that is not associated with any button, or event. Note i am not talking about keyboard buttons. in Borland builder. how does one define it in the header etc?

June 1st, 2004, 05:03 AM

Canderel

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Typically you'd want to add something to the form's class (a outside method, that can access all of the var's inside the form etc.)

Lets say you have a whole lot of editboxes with numbers in it, and you want a function that can return you the total of these boxes.

in mainform.h

PHP Code:


		
			
class TMainForm : public TForm

{

__published:    // IDE-managed Components

  TEdit *Box1;

  TEdit *Box2;

  TEdit *Box3;

  TEdit *Box4;

  TEdit *TotalBox;

  __fastcall BoxExit(TObject * Sender);

private:    // User declarations

   double total;

public:        // User declarations

  __fastcall TMainForm(TComponent* Owner);

  double GetTotal();    // <---  Define it in Public

};

then in your mainform.cpp

PHP Code:


		
			
 double Tmainform::GetTotal()  // <--- This can happen anywhere

{

  return StrToFloatDef(Box1->Text,0) + 

    StrToFloatDef(Box2->Text,0) +

    StrToFloatDef(Box3->Text,0) +

    StrToFloatDef(Box4->Text,0);

}

Then lets say when you exit any of the editboxes you have

PHP Code:


		
			
 void __fastcall Tmainform::BoxExit(TObject * Sender) 

{

  total = GetTotal();  // <--- Call it from any other place that is in Tmainform

  TotalBox->Text = FormatFloat("0.00",total);

}

June 1st, 2004, 10:30 AM

jake8

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Hi,
Thanks.
Is the function defined in public so access by other functions is possible?

June 2nd, 2004, 01:07 AM

Canderel

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I usually define it in public so that I can access it from other forms. You might have a different way to change the numbers in those editboxes, and then to be able to call them from elsewhere might be useful.

In this case however, you could define it as private too. Deciding what should be private and what public is a classic OOP question, but to me it's just a matter of practicality. (Coming from a delphi background)

Function writing with Borland Builder C++

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