Using gui objectNames when coding

[The physicist]

Hey all,

Complete noob to QT here. I am trying to write a gui for a program that I wrote in traditional c++ (command line application) - I want to populate a label widget with a value when I push a button on the GUI. The label's objectName is "label" - and my code looks something like this:

#include "brachygui.h"
#include "ui_brachygui.h"
#include <QLabel>
 
BrachyGUI::BrachyGUI(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::BrachyGUI)
{
    ui->setupUi(this);
}
 
BrachyGUI::~BrachyGUI()
{
    delete ui;
}
 
void BrachyGUI::on_pushButton_clicked()
{
    label->setText("Monday");
}

#include "brachygui.h"
#include "ui_brachygui.h"
#include <QLabel>

BrachyGUI::BrachyGUI(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::BrachyGUI)
{
    ui->setupUi(this);
}

BrachyGUI::~BrachyGUI()
{
    delete ui;
}

void BrachyGUI::on_pushButton_clicked()
{
    label->setText("Monday");
}

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When I build, I get the error "error: 'label' was not declared in this scope". Where do I define the label, or is it already defined somewhere, and I need to access it differently? I've searched the forums and google, but haven't been able to work it out

Thanks in advance.

[tbscope]

If you use designer, then the objects you've added via designer are available via the "ui" object. Example:

ui->label->setText("Monday");

ui->label->setText("Monday");

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[The physicist]

Tbscope, thanks, that's perfect!

I'm really looking forward to getting to grips with QT, it looks much better than MS Visual Studio (with the added bonus of being x-platform).

[The physicist]

Can anyone help me with a similar thing following on from this? How do I set the value of a label to a variable from elsewhere in the program? I just tried this

void gui_brachy::on_pushButton_clicked()
{
    function();
 
    ui->label->setText(variable);
}

void gui_brachy::on_pushButton_clicked()
{
    function();

    ui->label->setText(variable);
}

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where variable is in the function. I just tried it but I got an error saying that the variable had not been defined in this scope?

[squidge]

You'd write it in the same way as typical C++, pass the variable as a parameter, or use a class member variable.

So you'd have, for example "QString m_svariable" in your class, and just use "ui->label->setText(m_svariable)";

[The physicist]

Classes aren't something I've used in my limited experience of C++, so I will go away and read up them now, cheers

[squidge]

Good idea, you'll be using them a lot in Qt programming

[The physicist]

Just cracked it, thanks. I didn't realise that what I put in setText() has to be of type QString!

[The physicist]

Another day, another problem!

When I try to access labels via ui->label_X, some of them aren't appearing. I entered the name manually, but when I compile, I get the error " 'class ui_guibrachy' has no member name 'label_X'

Have I turned something off that I don't know about

I tried adding a button to see if that showed up, which it didn't. Could it be that I designed the ui on Mac OS X and today I'm using windows?!

Thanks.

[stampede]

When I try to access labels via ui->label_X, some of them aren't appearing. I entered the name manually, but when I compile, I get the error " 'class ui_guibrachy' has no member name 'label_X'

1. Open this file with designer and double-check the object's names.
2. Make sure you have saved changes.
3. Make sure that you compile correct .ui file ( check if its included in your .pro project file ) and include correct ui header in your sources.
4. Check for typos in source files.
5. Do a clean build ( make clean, qmake, make [debug/release] ) .

There is a big chance of success if you do all of this correctly

I tried adding a button to see if that showed up, which it didn't

You mean that you've added a button via designer and it wont show up in you app ? If yes, then double-check 2) and 3)

[The physicist]

1. Done
2. Done (closed and opened again to make sure they're there)
3. Done (all in the proj file)
4. Looks OK
5. Think I did this, Build->clean all

Any other ideas