I'm trying to find a widget that I added to the screen and do some manipulations with it, but the list of children is empty every time. What am I doing wrong?
Here is the code (to run it, create a new clean project and replace the text in MainWindow.cpp):
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <QLabel>
#include <QLayout>
#include <QList>
MainWindow::MainWindow(QWidget* parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
QLabel* wid = new QLabel("hello");
ui->centralWidget->layout()->addWidget(wid);
QList<QLabel*> list = ui->centralWidget->findChildren<QLabel*>();
qDebug() << list.isEmpty();
}
MainWindow::~MainWindow()
{
delete ui;
}
Related
so I an new to C++ and QT and I am trying to add a widget to a scroll area but without a layout as I want the widgets to be click and dragged.
Here's my code (main window.cpp):
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "player_window.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_pushButton_clicked()
{
player_window *player = new player_window(ui->scrollArea_WidgetContents);
player->setGeometry(50,50,450,130);
ui->scrollArea_WidgetContents->layout()->addWidget(player);
}
Thanks!
I have written a code to print an Icon accessed from FontAwesome installed in the system. I would like to change the color for the Icon printed on the Screen.I have tried using QPixmap and QIcon,but to no avail.Attached the output :
#include "MainWindow.h"
#include "ui_MainWindow.h"
#include <QPushButton>
#include <QGridLayout>
#include <QWidget>
#include <QLabel>
#include "qfonticon.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QWidget *centralWidget;
QGridLayout *gridLayout;
centralWidget = new QWidget(this);
gridLayout = new QGridLayout( centralWidget );
QFontIcon::addFont("/usr/share/fonts/fontawesome-webfont.ttf");
QIcon icon = QFontIcon::icon(0xf2e0,QColor(1,0,1,255));
//QFontIconEngine::addFile("/usr/share/fonts/fontawesome-webfont.ttf");
//QPixmap pix = QFontIconEngine::;
QPushButton *b = new QPushButton();
//QLabel *l = new QLabel();
b->setIcon(icon);
b->setIconSize(QSize(75,75));
//l->setPixmap(pix);
gridLayout->addWidget(b);
//gridLayout->addWidget(l);
this->setCentralWidget(centralWidget);
}
MainWindow::~MainWindow()
{
delete ui;
}
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPushButton>
#include <QWebEngineView>
#include <qDebug>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
#if 1
auto btn = new QPushButton;
ui->gridLayout->addWidget(btn);
qDebug()<<btn->winId();
#endif
auto web = new QWebEngineView;
ui->gridLayout->addWidget(web);
web->load(QUrl("http://www.google.com"));
}
MainWindow::~MainWindow()
{
delete ui;
}
That's the whole code.
Windows 10 , Qt 5.5 .
When I turn on the switch, winId() would be called, then the QtWebEngine can not work rightly.
What should I do ?
Don't call winId() until the widget is visible. You could set an eventFilter that is activated on QEvent::Show, for further information see http://doc.qt.io/qt-5/qobject.html#installEventFilter
I'm using QGraphicsDropShadowEffect to make my GUI look pretier. Minimal working sample:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QGraphicsDropShadowEffect>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QGraphicsDropShadowEffect *g = new QGraphicsDropShadowEffect(this);
ui->pushButton->setGraphicsEffect(g);
ui->pushButton_2->setGraphicsEffect(g);
ui->pushButton_3->setGraphicsEffect(g);
}
MainWindow::~MainWindow()
{
delete ui;
}
As you see, I have 3 buttons and want to have a fancy shadow at the top of every button. Although I set graphics effect on every button it can be seen only on the last button, heres the image:
How can I improve it and what is the cause?
This works:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QGraphicsDropShadowEffect>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QGraphicsDropShadowEffect *g1 = new QGraphicsDropShadowEffect(this);
QGraphicsDropShadowEffect *g2 = new QGraphicsDropShadowEffect(this);
QGraphicsDropShadowEffect *g3 = new QGraphicsDropShadowEffect(this);
ui->pushButton->setGraphicsEffect(g1);
ui->pushButton_2->setGraphicsEffect(g2);
ui->pushButton_3->setGraphicsEffect(g3);
}
MainWindow::~MainWindow()
{
delete ui;
}
but seem not to be the best solution I can have.
It's the normal behavior of the function you are calling
see documentation
http://qt-project.org/doc/qt-4.8/qgraphicsitem.html#setGraphicsEffect
If effect is the installed on a different item, setGraphicsEffect()
will remove the effect from the item and install it on this item.
Question asked twice: see Handling multiple ui files in Qt
I am new to Qt framwork , i have been given this simple task:
In the MainWindow , i have a submit button , once its clicked another total different window should appear
i thought of doing this by doing one extra UI file called From.ui file and to switch from MainWindow to Form once submit is clicked , this is my code:
//main.cpp
#include "mainwindow.h"
#include <QtGui/QApplication>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MainWindow mainWindow;
mainWindow.setOrientation(MainWindow::ScreenOrientationAuto);
mainWindow.showExpanded();
return app.exec();
}
//MainWindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "form.h"
#include <QtCore/QCoreApplication>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent), ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow:: SubmitClicked()
{
Form* f= new Form(this);
f->show();
f->raise();
f->activateWindow();
}
//Form.cpp
#include "form.h"
#include "ui_form.h"
Form::Form(QWidget *parent) :
QWidget(parent),
ui(new Ui::Form)
{
ui->setupUi(this);
}
Form::~Form()
{
delete ui;
}
this code compiled perfectly , but its not doing as expected , once submit is clicked , nothing is done...
can you please tell me whats wrong ?
It seems that SubmitClicked slot is not connected to clicked event of your button
Put a cout/printf at the top of your SubmitClicked method to make sure that it is called.