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Newbee question
I'm new to Qt and I can't figure out how to refresh widgets after they have been displayed. I read on the Internet that one way to refresh is to call "QCoreApplication::processEvents()", but the following code creates a label that shows "Hello" even after calling "setText" and attempting to refresh.
#include <QApplication>
#include <QLabel>
int main(int argc, char * argv[])
{
QApplication app(argc, argv);
QLabel label("Hello");
label.show();
app.exec();
label.setText("Goodbye");
QCoreApplication::processEvents();
}
You are doing it the wrong way. Totally the wrong way.
I suggest you take a look at some Qt examples before moving along.
Jan
P.S. I think the main problem may be that you still execute code after app.exec()
Edit: And please, use code tags then posting code
I went through the entire Cannon tutorial and I still cannot figure out how to change the state of widgets. Obviously I wouldn't have posted if I thought I could figure it out for myself.
I take it from your response (although I'm not sure) that the only way to change the state of a widget is through interaction with buttons etc. (via the signal-slot mechanism). However, I have external code from which I want to change the state of widgets, so I thought I could add functions to my widget subclasses that allows me, for example, to set the text of a label after the window has already been displayed.
I've never posted in a programming forum so I have no idea what code tags are.
Try:
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Source code
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#include <QtGui/QApplication>
#include <QtGui/QLabel>
int main(int argc, char * argv[])
{
QApplication app(argc, argv);
QLabel label;
label.show();
app.processEvents();
label.setText( "Hello" );
sleep( 5 );
app.processEvents();
label.setText( "Good-bye" );
sleep( 5 );
app.processEvents();
return app.exec();
}
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I've never posted in a programming forum so I have no idea what code tags are.
When you join a new board it's polite to read the FAQ/guidlines
QtForum.org Guidelines
here's a tip - newbies should never need processEvents.
here's another tip - any code after exec() is useless. The qt app and event loop as exited.
If you have a problem, CUT and PASTE your code. Do not retype or simplify it. Give a COMPLETE and COMPILABLE example of your problem. Otherwise we are all guessing the problem from a fabrication where relevant details are often missing.
Sorry if I maybe was a little unpolite, but as you used code after the exec() command it looked like you hadn't read much in the tutorials.
Jan
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Missing libgles_cm.lib
(May 7th 2012, 3:08pm)
