Right write in of the command

[nnnkkk]

Hello..
I just started with 2010 c++ builder.

I would like to ask for right write in of the command.
I want to use result from Unit1->Form1 on the Form2.
For exemple,Form1->res1=20,and on the Form2->res4=(res1/res3)
And then
on the Form1= label->Caption=((res4))
I tried meny types of code And i cant get it right.res1 is always = 0 on the Form 2

Thanks for help

 

[trollacious]

Where are you declaring res1? One way is to put it in a file that's included in both Form1 and Form2. You wouldn't use Form1->res1 then, just res1.

If you want to use Form1->res1, make sure res1 is a public variable and not private.

The same goes for res4.

Lee

 

[nnnkkk]

Hi.Thanks for reply..res1 I declared on the form1.
Do you mean , should I declace res1 in Project1.cpp file.that include All forms 1,2,3,4.I gonna try it ..Thanks for now

 

[nnnkkk]

I tried to do it those ways but doesnt work.
example:
I declared on the form1 int a,b,c and currency res1,res2,
a=1,b=2,c=3.
res1=a+b+c
and then on the form2 i need to use res1
res3=(res1/res4)*x
Form1->Label1->Caption=((res3)) always showing 0 so res1 on the form2==0.
If both form are public no private how to right declare or write a comand of res1=Form1->res1 or??
thanks for help

 

[luckieluc]

I think it is better to declare those variables private and use public setters and getters to set and get the value of the variables.

in "Form1.h":

[...]

private:
int a;
int b;
int c;

public:
void __fastcall seta(int q) {a=q;};
int geta() {return a;};

and so on... Think object oriented.

It is my impression you are very new in programming C++ Builder?

 

[nnnkkk]

Hello,thaks for reply.. It is done. But I had a problems
when i declared variables as private.I done it by first way as you advised.I found some errors in the code..And yes Im very new in c++ builder.. thanks

 

[luckieluc]

nnnkkk wrote:

I declared on the form1 int a,b,c and currency res1,res2,
a=1,b=2,c=3.
res1=a+b+c

It is strange to read this.

in h-file:
...
__published: // IDE-managed Components
private: // User declarations

public: // User declarations
int a;
int b;
int c;
int res1;
int res2;
__fastcall TForm4(TComponent* Owner);
....

in cpp-file:

__fastcall TForm4::TForm4(TComponent* Owner)
: TForm(Owner)

{
// data members of a class cannot be initialized where they
//are declared in the class body. These data members should
//be initialized by the class's constructor, or they can be
//assigned values by "set" function. (C++ how to program
//from Deitel & Deitel)
//This is the error you made.

a=1;
b=2;
C=3;
res1=a+b+c;
}

now because a,b,c,res1 are declared public, the call in Form2: Form1->Label1->Caption=((res3)) won't be 0

 

[luckieluc]

Please, do not misunderstand me. It is not because you are new in C++ this wasn't a good question. It is a common error and I think many experienced C++ programmers are forgotten why a public declared member that is not initiated correctly can not called outside the class.