C / C++ / MFC

2-Aug-01 5:53

Hi,
I am developing a Document/view application that display different kind of curve. To do so i've used a common CView derived class... but now I want to add some control inside my view on the drawing area. Just for a demo I've insert "false button". ie bitmap picture and I'm trapping their position on LButtonDown... so it's just for demo.

For now I'm seaching a good tutorial or code example who give me the possibility to add all kind of control in a view. I still need to be able to draw (whit dc's function) and to use splitter curve.

So if anyone have something who can help

thank

Rémi Morin
Rmorin@Operamail.com
Remi.Morin@Lyrtech.com

Naresh Karamchetty2-Aug-01 7:46

Naresh Karamchetty

2-Aug-01 7:46

I'm almost certain you can't add a control to a CView-derived vie wusing the resource editor. You would have to try it programmatically. One idea is to declare a member variable of type CButton, initialize it in your view class's constructor, and then call its Show function in the view's OnDraw function.

I must admit, I'm not entirely clear as to how you would go about handling events from such a button. I believe you have to assign a control ID to the button and use the ON_BN_CLICKED macro to map the message to a specific function.

"What would this country be without this great land of our?" -Ronald Reagan

Remi Morin2-Aug-01 8:59

2-Aug-01 8:59

Hehe!
Same for me it's the only thing I've found but for now I was'nt able to assing an Id and I don't want to edit myself the ressources. So I derived the class of the control I wanna use and override everything I need. It's not clean but it work... to my mind they must exist a better way to do so.

Still waiting for! Smile | :)

Thank you for you'r answer

Remi Morin
Rmorin@Operamail.com
Remi.Morin@Lyrtech.com

Naresh Karamchetty2-Aug-01 10:47

Naresh Karamchetty

2-Aug-01 10:47

To assign an ID you just use one of those #define macros. Editing the resource file won't help because everytime the resources are compiled or edited, or soemthing like that, the resource file is erased and written anew.

"What would this country be without this great land of our?" -Ronald Reagan

Jake Palmer2-Aug-01 12:16

Jake Palmer

2-Aug-01 12:16

The way to declare IDs is to go to the Resources tab, right click on the top level folder and select Resource Symbols. It has an icon of text "ID=", which demonstrates its use as defining global IDs. Click "new" and you can make "ID_BUTTON_SOMETHING" and then use that anywhere in your project.

Handling that button will require adding an entry to the message map. In the cpp file of the class you want to receive the message (your view class, most likely), after the BEGIN_MESSAGE_MAP, add the entry:
ON_COMMAND(ID_BUTTON_SOMETHING, OnButtonSomething).

Button clicks should automatically call the function OnButtonSomething, which you will need to declare in the header file (afx_msg void OnButtonSomething()) and implement in the cpp file.

Hope this helps Cool | :cool:

Jake

Remi Morin17-Aug-01 5:04

17-Aug-01 5:04

thank you very much for you'r help. this subject is now a good tutorial "HOW TO: Use any kind of control in a view"

now every control work very well

thanks
Smile | :)

Remi Morin
Rmorin@Operamail.com
Remi.Morin@Lyrtech.com

newbie question

User 81472-Aug-01 5:39

User 8147

2-Aug-01 5:39

Hi folks

I'm in the middle of my 1st C++ project and would like a little guidance
where my books seem to be embarrassingly lacking.

I would like to have a function which returns an array of floats,except
(strangely) I can't find any examples of such a function or even a decent
prototype.
It's purely a syntactical question..

Anyone?

Thanks
J
Smile | :)

2-Aug-01 6:10

There are several possable ways to do this. Here are two examples

1. Pass the array to the function by reference:

void MyFunction(float* pFloatArray);

2. Dynamically allocate an array to return:

float* MyFunction()
{
float* pFloat = new float[10];
return pFloat;
}

//In this case be sure to delete the memory when you're done!

void main()
{
float* pFloat = MyFunction();

//do your processing

delete [] pFloat;
}

Remi Morin2-Aug-01 6:14

2-Aug-01 6:14

here a little example just to explain if

// floatarray.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdio.h>
bool DoSomethingOnFloat(float *paramFloatArray,int paramSizeOfArray);
bool DoSomethingOnFloat2(float paramFloatArray[],int paramSizeOfArray);

int main(int argc, char* argv[])
{
int i;

float FloatArray[10];
for(i=0;i<200;i++)
{
//filling with garbage
FloatArray[i] = (float)i;
}
DoSomethingOnFloat(FloatArray,10);
DoSomethingOnFloat2(FloatArray,10);
return 0;
}
/******************************************************************
here it's the "pointer way" the weird thing to a newbies is the way
we extract data from the array
******************************************************************/
bool DoSomethingOnFloat(float *paramFloatArray,int paramSizeOfArray)
{
int i;
for(i=0;i

Christian Graus2-Aug-01 12:54

Christian Graus

2-Aug-01 12:54

The advice given is correct, but you can also return a vector of floats, which is safer, but may be a subject you'll learn down the track. I'd suggest buying a good book on STL ( Standard Template Library ) and using it, if not for this assignment, then certainly down the track.

Christian

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