C++/Qt/QLabel
Содержание
Add a label and display
#include <QApplication>
#include <QLabel>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QLabel *label = new QLabel("Hello Qt!");
label->show();
return app.exec();
}
Adding image to QLabel
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtGui>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QLabel topLevelLabel;
QPixmap pixmap(":/images/tux.png");
topLevelLabel.setPixmap(pixmap);
topLevelLabel.setMask(pixmap.mask());
topLevelLabel.show();
return app.exec();
}
Clock label
Foundations of Qt Development\Chapter06\clocklabel\clocklabel.cpp
/*
* Copyright (c) 2006-2007, Johan Thelin
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of APress nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <QTimer>
#include <QTime>
#include "clocklabel.h"
ClockLabel::ClockLabel( QWidget *parent ) : QLabel( parent )
{
QTimer *timer = new QTimer( this );
timer->setInterval( 1000 );
connect( timer, SIGNAL(timeout()), this, SLOT(updateTime()) );
timer->start();
updateTime();
}
void ClockLabel::updateTime()
{
setText( QTime::currentTime().toString( "hh:mm" ) );
}
Foundations of Qt Development\Chapter06\clocklabel\clocklabel.h
/*
* Copyright (c) 2006-2007, Johan Thelin
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of APress nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef CLOCKLABEL_H
#define CLOCKLABEL_H
#include <QLabel>
class ClockLabel : public QLabel
{
Q_OBJECT
public:
ClockLabel( QWidget *parent = 0 );
private slots:
void updateTime();
};
#endif // CLOCKLABEL_H
Foundations of Qt Development\Chapter06\clocklabel\main.cpp
/*
* Copyright (c) 2006-2007, Johan Thelin
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of APress nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <QApplication>
#include "clocklabel.h"
int main( int argc, char **argv )
{
QApplication app( argc, argv );
ClockLabel clock;
clock.show();
return app.exec();
}
Create a Label and show
#include <QApplication>
#include <QLabel>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QLabel label("Hello World");
label.show();
return a.exec();
}
Set QLabel buddy
/*
* Copyright (c) 2006-2007, Johan Thelin
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of APress nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <QApplication>
#include <QDialog>
#include <QLineEdit>
#include <QLabel>
#include <QGridLayout>
int main( int argc, char **argv )
{
QApplication app( argc, argv );
QDialog dlg;
QLabel *fooLabel = new QLabel( "&Foo:" );
QLabel *barLabel = new QLabel( "&Bar:" );
QLineEdit *fooEdit = new QLineEdit();
QLineEdit *barEdit = new QLineEdit();
fooLabel->setBuddy( fooEdit );
barLabel->setBuddy( barEdit );
QGridLayout *layout = new QGridLayout( &dlg );
layout->addWidget( fooLabel, 0, 0 );
layout->addWidget( fooEdit, 0, 1 );
layout->addWidget( barLabel, 1, 0 );
layout->addWidget( barEdit, 1, 1 );
dlg.show();
return app.exec();
}
Set tooltip for QLabel
Foundations of Qt Development\Chapter09\statusbar\main.cpp
/*
* Copyright (c) 2006-2007, Johan Thelin
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of APress nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <QApplication>
#include <QMainWindow>
#include <QTextEdit>
#include <QStatusBar>
#include <QLabel>
#include <QProgressBar>
class MainWindow : public QMainWindow
{
public:
MainWindow();
};
MainWindow::MainWindow() : QMainWindow()
{
setCentralWidget( new QTextEdit( this ) );
QStatusBar *statusBar = this->statusBar();
QProgressBar *progressBar = new QProgressBar();
QLabel *mode = new QLabel( tr(" EDIT ") );
QLabel *modified = new QLabel( tr(" Y ") );
QLabel *size = new QLabel( tr(" 999999kB ") );
mode->setMinimumSize( mode->sizeHint() );
mode->setAlignment( Qt::AlignCenter );
mode->setText( tr("EDIT") );
mode->setToolTip( tr("The current working mode.") );
statusBar->addPermanentWidget( mode );
modified->setMinimumSize( modified->sizeHint() );
modified->setAlignment( Qt::AlignCenter );
modified->setText( tr("N") );
modified->setToolTip( tr("Indicates if the current document has been modified or not.") );
size->setMinimumSize( size->sizeHint() );
size->setAlignment( Qt::AlignRight | Qt::AlignVCenter );
size->setText( tr("%1kB ").arg(0) );
size->setToolTip( tr("The memory used for the current document.") );
progressBar->setTextVisible( false );
progressBar->setRange( 0, 0 );
statusBar->addWidget( progressBar, 1 );
statusBar->addWidget( modified );
statusBar->addWidget( size );
statusBar->showMessage( tr("Ready"), 2000 );
}
int main( int argc, char **argv )
{
QApplication app( argc, argv );
MainWindow window;
window.show();
return app.exec();
}
Using HTML with QLabel
#include <QApplication>
#include <QMainWindow>
#include <QLabel>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QMainWindow mainWindow;
QLabel *label =new QLabel("<center>Central Widget</center>");
mainWindow.setCentralWidget(label);
mainWindow.show();
return a.exec();
}