How to launch other applications in Qt
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== Code Example == | == Code Example == | ||
| − | * Download [[File:QtAppLauncher.zip]].[[Category:MeeGo]] [[Category:Symbian]] | + | * Download [[File:QtAppLauncher.zip]].[[Category:MeeGo Harmattan]] [[Category:Symbian]] |
Revision as of 13:53, 13 June 2012
This code example shows how to start other applications from within a Qt application. It demonstrates QDesktopServices::openUrl() for opening URLs in the default browser and QProcess for launching arbitrary applications.
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Code Example
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Platform Security
Article
Contents |
Launching web browser
The class QDesktopServices provides methods for accessing common desktop services, like browser, player, e-mail client, etc. We use QDesktopServices::openUrl(), which opens the given URL in the appropriate Web browser for the user's desktop environment, and returns true if successful; otherwise returns false. If the URL is a reference to a local file (i.e., the URL scheme is "file") then it will be opened with a suitable application instead of a Web browser. For example, you can use URL "file:///c:/data/abc.png" to open abc.png in its default application. similarly you can play audio/video.
Header required
#include <QDesktopServices>
#include <QUrl>
Source code
//openUrl is static method of class QDesktopServices, so no need to create instance of it.
//Open URL in browser
QDesktopServices::openUrl(QUrl("http://www.developer.nokia.com/Community/Discussion/forumdisplay.php?40-General-Symbian-C"));
Launching RealPlayer
QProcess is used to start external programs and to communicate with them.
Header required
#include <QDesktopServices>
#include <QUrl>
Source code
//openUrl is static method of class QDesktopServices, so no need to create instance of it.
//to open vedio file in realplayer give full path here.
QDesktopServices::openUrl(QUrl("file:///e:/Videos/Nokia 5800 XpressMusic.mp4"));
Launching Email Client
Header required
#include <QDesktopServices>
#include <QUrl>
Source code
//openUrl is static method of class QDesktopServices, so no need to create instance of it.
//Open email client.
QDesktopServices::openUrl(QUrl("mailto:ratang.gir@gmail.com?subject=Testing feedback&body=HelloFriend"));
Launching other applications
Header required
#include <QProcess>The signal error() of QProcess is emitted when an error occurs with the process. The specified error describes the type of error that occurred.
Header file
void processError(QProcess::ProcessError err);
QProcess process;
Source code
QtAppLauncher::QtAppLauncher(QWidget *parent)
: QMainWindow(parent)
{
//connect error() to slot processError() to get error, if occurs.
QObject::connect( &process, SIGNAL(error(QProcess::ProcessError)),
this, SLOT(processError(QProcess::ProcessError)));
//pass the name of executable that you want to launch. i have installed helloworld so passed helloworld.
process.start("helloworld");
}
//get errors, if any
void QtAppLauncher::processError(QProcess::ProcessError err)
{
switch(err)
{
case QProcess::FailedToStart:
QMessageBox::information(0,"FailedToStart","FailedToStart");
break;
case QProcess::Crashed:
QMessageBox::information(0,"Crashed","Crashed");
break;
case QProcess::Timedout:
QMessageBox::information(0,"FailedToStart","FailedToStart");
break;
case QProcess::WriteError:
QMessageBox::information(0,"Timedout","Timedout");
break;
case QProcess::ReadError:
QMessageBox::information(0,"ReadError","ReadError");
break;
case QProcess::UnknownError:
QMessageBox::information(0,"UnknownError","UnknownError");
break;
default:
QMessageBox::information(0,"default","default");
break;
}
}
Postconditions
The code snippet is expected to launch browser, realplayer and helloworld application.
Code Example
- Download File:QtAppLauncher.zip.
