Related
I am working on a Save dialog for my qt app. Everything works, but if no file extension is added behind the filename, it won't automatically be saved with the file extension although the filter is selected.
I know i need to set a defaultsuffix option, but even if i do, then it still won't add the extension automatically if its not given.
I found several other similar questions, where i read it works in windows but it could fail on linux distro's. If so, is there a simple workaround? Because right now, i don't have a working solution...
void MainWindow::on_actionSave_Chart_As_triggered()
{
QFileDialog *fileDialog = new QFileDialog;
fileDialog->setDefaultSuffix("files (*);;AstroQt aqt (*.aqt)");
QString fileName = fileDialog->getSaveFileName(this, "Save Radix", ui->label_2->text() +".aqt", "AstroQT(*.aqt)");
qDebug() << " save file name " << fileName << endl;
QFile file(fileName);
if (!file.open(QFile::WriteOnly | QFile::Text)) {
QMessageBox::warning(this, "Warning", "Cannot save file: " + file.errorString());
return;
}
setWindowTitle(fileName);
QTextStream out(&file);
QString text = "text that will be saved...";
out << text;
file.close();
}
Edit: After trying multiple solutions, none seemed to work. But it should have, i guess. Why else is there a aftersuffix function...? For now i solved it doing it manually. But i'm not happy with it, there should be a better solution/explanation.
// add extension if none is found.
if(!fileName.endsWith(".aqt"))
fileName.append(".aqt");
If you use the static method getSaveFileName things seems to work correctly:
#include <QFileDialog>
#include <QApplication>
#include <QDebug>
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
QString fileName = QFileDialog::getSaveFileName(
nullptr, QObject::tr("Save File"),
"teste.aqt",
QObject::tr("AstroQt (*.aqt)"));
qDebug() << " save file name " << fileName << endl;
return app.exec();
}
I get the correct file name with the extension, if I type something without the extension.
If you take a look at QFileDialog documentation, you will see that getSaveFileName() is an static function. Because of this, there is no way for this method to access a member of the instance of the class that makes use of setDefaultSuffix(). So whatever you set in fileDialog->setDefaultSuffix(...) has nothing to do with what the getSaveFileName() function does.
In ordertTo make it work, you have to run the dialog directly from the instance. You should do something like this:
QFileDialog fileDialog(this, "Choose file to save");
fileDialog.setDefaultSuffix("json");
fileDialog.setNameFilter("json-files (*.json)");
fileDialog.exec();
QFile f(fileDialog.selectedFiles().first());
QFileInfo fileInfo(f);
QString FILE_NAME(fileInfo.fileName());
I have been all day long googling for a solution and changing my code, but no luck.
Basically, I have added translation to my app. It is working fine except here:
QString MainWindow::getMessage(Messages msg) {
static const char* const messages[] = {
QT_TR_NOOP("Setting power on"),
QT_TR_NOOP("Reading ID..."),
QT_TR_NOOP("Programming..."),
QT_TR_NOOP("Setting write-protect"),
QT_TR_NOOP("Finished ok"),
QT_TR_NOOP("PROGRAMMED OK"),
QT_TR_NOOP("ERROR!"),
QT_TR_NOOP("OK"),
QT_TR_NOOP("The programmer is not connected.\nPlease check the connection."),
QT_TR_NOOP("Disconnect the board, it is in short!!"),
QT_TR_NOOP("ERROR: Supply voltage too low (1 Volt is required, Measured: 0.0 Volt)."),
QT_TR_NOOP("Board is already programmed and write protected."),
QT_TR_NOOP("Check device connection or there is short."),
QT_TR_NOOP("Unknown error.")
};
return tr(messages[msg]);
}
However, I don't get the translation. The files for translation seems to be ok, the UI translations are applied fine.
I also tried this:
static const char* const messages[] = {
QT_TRANSLATE_NOOP("test", "Setting power on"),
QT_TRANSLATE_NOOP("test", "Reading ID..."),
QT_TRANSLATE_NOOP("test", "Programming..."),
QT_TRANSLATE_NOOP("test", "Setting write-protect"),
QT_TRANSLATE_NOOP("test", "Finished ok"),
QT_TRANSLATE_NOOP("test", "PROGRAMMED OK"),
QT_TRANSLATE_NOOP("test", "ERROR!"),
QT_TRANSLATE_NOOP("test", "OK"),
QT_TRANSLATE_NOOP("test", "The programmer is not connected.\nPlease check the connection."),
QT_TRANSLATE_NOOP("test", "Disconnect the board, it is in short!!"),
QT_TRANSLATE_NOOP("test", "ERROR: Supply voltage too low (1 Volt is required, Measured: 0.0 Volt)."),
QT_TRANSLATE_NOOP("test", "Board is already programmed and write protected."),
QT_TRANSLATE_NOOP("test", "Check device connection or there is short."),
QT_TRANSLATE_NOOP("test", "Unknown error.")
};
Then, I have a method to get the message:
QString MainWindow::getMessage(Messages msg) {
return qApp->translate("test", messages[msg]);
}
But it doesn't work either.
Any tips or suggestions?
I have found the real issue here.
Usually translators are installed at main.cpp, so the translator object remains in memory.
However, in my case, I was switching the translator after the user changes the language at settings dialog, using a local variable but void QCoreApplication::installTranslator ( QTranslator * translationFile ) [static] needs a pointer. That local variable is removed as soon as the function exits.
So, I declared a QTranslator object on my class, so it keeps in memory.
Maybe not applicable in this situation, but often people forget to place the Q_OBJECT macro in the class declaration. Resulting in (amongst others) tr() not working.
I was preparing a simpler source to upload here but now it is working fine! I rebooted my PC yesterday, you know, sometimes a reboot fixes everything (?).
Anyway, here is some source as it was requested. And by the way, I'm doing the translation on the fly, and by letting the user to choose the language (not by detecting locales):
This is main.cpp (nothing was added by me):
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
This is mainwindow.cpp:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDir>
#include <QTranslator>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QDir d(":/translations/");
QStringList files = d.entryList(QStringList("*.qm"));
qDebug("There are %d files for translation", files.count());
// Now let's fill the combobox
this->ui->comboBox->clear();
for (int i = 0; i < files.count(); ++i) {
QTranslator translator;
translator.load(files[i], ":/translations/");
QString language = translator.translate("MainWindow",
"English");
this->ui->comboBox->addItem(language);
}
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_comboBox_currentIndexChanged(int index)
{
// Now, based on the new itemindex, let's change the translator
QString selectedLang = this->ui->comboBox->itemText(index);
QString language;
QDir d(":/translations/");
QStringList files = d.entryList(QStringList("*.qm"));
for (int i = 0; i < files.count(); ++i) {
QTranslator translator;
translator.load(files[i], ":/translations/");
language = translator.translate("MainWindow",
"English");
if (language == selectedLang) {
if (!qApp->installTranslator(&translator)) {
qDebug("ERROR INSTALLING TRANSLATOR !!!");
}
this->uiTranslate();
break;
}
}
}
/// This function translates all the UI texts:
void MainWindow::uiTranslate(void) {
this->setWindowTitle(tr("MainWindow"));
// Just for testing, also show all the messages
for (int i = 0; i < MSG_LAST; ++i) {
this->ui->textBrowser->append(this->getMessage((Messages)i));
}
}
QString MainWindow::getMessage(Messages idx) {
static const char* const messagesText[MSG_LAST] = {
QT_TR_NOOP("Hello!"),
QT_TR_NOOP("Bye bye"),
QT_TR_NOOP("Nice to meet you")
};
return (tr(messagesText[idx]));
}
in this test app, the UI just has a combobox and a text browser.
The combobox is filled with the languages included on the resource file.
When I change the combobox, the mainwindow title is changed and the messages are printed in the right language.
Thanks anyway!
Best regards,
I am trying to use a QSettings object with an IniFormat for UserScope settings loaded at the start of the application. I moved the QSettings setup code into a separate method and call it from main() as shown in this snippet:
#include <QDebug>
#include <QSettings>
#include <QStringList>
void loadSettings()
{
qDebug() << "[BEGIN] loadSettings()";
QCoreApplication::setOrganizationName("Org");
QCoreApplication::setApplicationName("App");
QSettings settings(QSettings::IniFormat,
QSettings::UserScope,
"Org",
"App");
settings.setValue("TheAnswer", "42");
QStringList keys = settings.allKeys();
qDebug() << "Loaded " << keys.size() << " keys.";
qDebug() << "[END] loadSettings()";
}
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
loadSettings();
QSettings settings;
QStringList keys = settings.allKeys();
qDebug() << "Settings has " << keys.size() << " keys.";
// Empty
qDebug() << settings.value("TheAnswer").toString();
return a.exec();
}
The resulting output is:
[BEGIN] loadSettings()
Loaded 1 keys.
[END] loadSettings()
Settings has 0 keys.
""
Looking at the documentation for QSettings, it states that the usage of QCoreApplication to set the organization name and application name would allow the usage of the convenience QSettings creation method from anywhere in the application, so my understanding is that the code snippet should be able to access the value stored with key "TheAnswer" that was loaded by the loadSettings() method. Yet, when I create a new QSettings object using the convenience method, it has no key/value pairs. I verified the ini file is created and has correct data. What am I missing?
I believe the problme is that default format is QSettings::NativeFormat instead of QSettings::IniFormat, which you are using.
I noticed that there's a static QSettings::setDefaultFormat() function, so I would try adding this to your loadSettings() function:
QSettings::setDefaultformat( QSettings::IniFormat );
Also, once you've set the application/organization and default format, I don't think you need to pass any arguments to the QSettings constructor in your loadSettings() function.
I'm attempting to get readings from a device using the bluetooth Health Device Profile (specifically, an Nonin Onyx II 9560BT). Using this guide, I've been able to do so using python over dbus. Now I'm trying to port it over to C++, and as I'm already using QT in the application, I'm using the QT DBus bindings.
So far I've gotten to the following short program based on this API to test it:
#include <QtCore/QCoreApplication>
#include <QtCore/QDebug>
#include <QtCore/QStringList>
#include <QtDBus/QtDBus>
int main(int argc, char **argv)
{
QCoreApplication app(argc, argv);
if (!QDBusConnection::sessionBus().isConnected()) {
fprintf(stderr, "Cannot connect to the D-Bus session bus.\n"
"To start it, run:\n"
"\teval `dbus-launch --auto-syntax`\n");
return 1;
}
QDBusInterface iface("org.bluez","/org/bluez","org.bluez.HealthManager",QDBusConnection::systemBus(),0);
QVariantMap map;
map.insert("DataType",ushort(1004));//same result with simply 1004
map.insert("Role","Sink");
map.insert("Description","HDP Test Manager"); //Optional
//map.insert("ChannelType","Reliable");//Optional, same result with or without
//QList<QVariant> argumentList;
//argumentList.append(map);
QDBusPendingReply<> r = iface.call("CreateApplication",map);
qDebug() << r.reply();
qDebug() << r.error();
return 0;
}
As far as I can tell, the dict object taken by "CreateApplication" corresponds to an a{sv} which in QT corresponds to the QVariantMap.
However, I keep getting this error:
QDBusMessage(type=Error, service="", error name="org.bluez.Error.InvalidArguments", error message="Invalid arguments in method call", signature="", contents=([]) )
Question: What am I doing wrong?
Based on the guides at freedesktop.org, the qt docs and the mighty google, this is as far as I've gotten.
Thanks for any/all help!
/Keyz182
It works now. It seems that the ushort(0x1004) was getting cast by the QVariant to an int, and thus being picked up as a uint32 by the bluez code, which is not what was expected.
To fix it I did the following (there may be another way, but this worked for me).
I added a Metatype declaration for ushort, then registered it. then, created a QVariant containing the value, and used the QVariants convert method to set the metatype as a ushort (or uint16 when exposed to dbus).
#include <QtCore/QCoreApplication>
#include <QtCore/QDebug>
#include <QtCore/QStringList>
#include <QtDBus/QtDBus>
Q_DECLARE_METATYPE(ushort); //Added this to declare ushort as a metatype
int main(int argc, char **argv)
{
QCoreApplication app(argc, argv);
int ushorttype = qDBusRegisterMetaType<ushort>(); //Register the ushort metatype and get it's id
if (!QDBusConnection::sessionBus().isConnected()) {
fprintf(stderr, "Cannot connect to the D-Bus session bus.\n"
"To start it, run:\n"
"\teval `dbus-launch --auto-syntax`\n");
return 1;
}
QDBusInterface iface("org.bluez","/org/bluez","org.bluez.HealthManager",QDBusConnection::systemBus(),0);
QVariant dt(0x1004);
dt.convert((QVariant::Type)ushorttype); //convert to the new type
QVariantMap map;
map.insert("DataType",dt);
map.insert("Role","Sink");
map.insert("Description","HDP Test Manager"); //Optional
QDBusPendingReply<> r = iface.call("CreateApplication",map);
qDebug() << r.isValid();
qDebug() << r.reply();
return 0;
}
I have a Qt GUI application running on Windows that allows command-line options to be passed and under some circumstances I want to output a message to the console and then quit, for example:
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
if (someCommandLineParam)
{
std::cout << "Hello, world!";
return 0;
}
MainWindow w;
w.show();
return a.exec();
}
However, the console messages do not appear when I run the app from a command-prompt. Does anyone know how I can get this to work?
Windows does not really support dual mode applications.
To see console output you need to create a console application
CONFIG += console
However, if you double click on the program to start the GUI mode version then you will get a console window appearing, which is probably not what you want. To prevent the console window appearing you have to create a GUI mode application in which case you get no output in the console.
One idea may be to create a second small application which is a console application and provides the output. This can call the second one to do the work.
Or you could put all the functionality in a DLL then create two versions of the .exe file which have very simple main functions which call into the DLL. One is for the GUI and one is for the console.
Add:
#ifdef _WIN32
if (AttachConsole(ATTACH_PARENT_PROCESS)) {
freopen("CONOUT$", "w", stdout);
freopen("CONOUT$", "w", stderr);
}
#endif
at the top of main(). This will enable output to the console only if the program is started in a console, and won't pop up a console window in other situations. If you want to create a console window to display messages when you run the app outside a console you can change the condition to:
if (AttachConsole(ATTACH_PARENT_PROCESS) || AllocConsole())
void Console()
{
AllocConsole();
FILE *pFileCon = NULL;
pFileCon = freopen("CONOUT$", "w", stdout);
COORD coordInfo;
coordInfo.X = 130;
coordInfo.Y = 9000;
SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), coordInfo);
SetConsoleMode(GetStdHandle(STD_OUTPUT_HANDLE),ENABLE_QUICK_EDIT_MODE| ENABLE_EXTENDED_FLAGS);
}
int main(int argc, char *argv[])
{
Console();
std::cout<<"start##";
qDebug()<<"start!";
You can't use std::cout as others have said,my way is perfect even for some code can't include "qdebug" !
So many answers to this topic. 0.0
So I tried it with Qt5.x from Win7 to Win10. It took me some hours to have a good working solution which doesn't produce any problems somewhere in the chain:
#include "mainwindow.h"
#include <QApplication>
#include <windows.h>
#include <stdio.h>
#include <iostream>
//
// Add to project file:
// CONFIG += console
//
int main( int argc, char *argv[] )
{
if( argc < 2 )
{
#if defined( Q_OS_WIN )
::ShowWindow( ::GetConsoleWindow(), SW_HIDE ); //hide console window
#endif
QApplication a( argc, argv );
MainWindow *w = new MainWindow;
w->show();
int e = a.exec();
delete w; //needed to execute deconstructor
exit( e ); //needed to exit the hidden console
return e;
}
else
{
QCoreApplication a( argc, argv );
std::string g;
std::cout << "Enter name: ";
std::cin >> g;
std::cout << "Name is: " << g << std::endl;
exit( 0 );
return a.exec();
}
}
I tried it also without the "CONFIG += console", but then you need to redirect the streams and create the console on your own:
#ifdef _WIN32
if (AttachConsole(ATTACH_PARENT_PROCESS) || AllocConsole()){
freopen("CONOUT$", "w", stdout);
freopen("CONOUT$", "w", stderr);
freopen("CONIN$", "r", stdin);
}
#endif
BUT this only works if you start it through a debugger, otherwise all inputs are directed towards the system too. Means, if you type a name via std::cin the system tries to execute the name as a command. (very strange)
Two other warnings to this attempt would be, that you can't use ::FreeConsole() it won't close it and if you start it through a console the app won't close.
Last there is a Qt help section in QApplication to this topic. I tried the example there with an application and it doesn't work for the GUI, it stucked somewhere in an endless loop and the GUI won't be rendered or it simply crashes:
QCoreApplication* createApplication(int &argc, char *argv[])
{
for (int i = 1; i < argc; ++i)
if (!qstrcmp(argv[i], "-no-gui"))
return new QCoreApplication(argc, argv);
return new QApplication(argc, argv);
}
int main(int argc, char* argv[])
{
QScopedPointer<QCoreApplication> app(createApplication(argc, argv));
if (qobject_cast<QApplication *>(app.data())) {
// start GUI version...
} else {
// start non-GUI version...
}
return app->exec();
}
So if you are using Windows and Qt simply use the console option, hide the console if you need the GUI and close it via exit.
No way to output a message to console when using QT += gui.
fprintf(stderr, ...) also can't print output.
Use QMessageBox instead to show the message.
Oh you can Output a message when using QT += gui and CONFIG += console.
You need printf("foo bar") but cout << "foo bar" doesn't works
Something you may want to investigate, at least for windows, is the AllocConsole() function in the windows api. It calls GetStdHandle a few times to redirect stdout, stderr, etc. (A quick test shows this doesn't entirely do what we want it to do. You do get a console window opened alongside your other Qt stuff, but you can't output to it. Presumably, because the console window is open, there is some way to access it, get a handle to it, or access and manipulate it somehow. Here's the MSDN documentation for those interested in figuring this out:
AllocConsole():
http://msdn.microsoft.com/en-us/library/windows/desktop/ms681944%28v=vs.85%29.aspx
GetStdHandle(...):
http://msdn.microsoft.com/en-us/library/windows/desktop/ms683231%28v=vs.85%29.aspx
(I'd add this as a comment, but the rules prevent me from doing so...)
I used this header below for my projects. Hope it helps.
#ifndef __DEBUG__H
#define __DEBUG__H
#include <QtGui>
static void myMessageOutput(bool debug, QtMsgType type, const QString & msg) {
if (!debug) return;
QDateTime dateTime = QDateTime::currentDateTime();
QString dateString = dateTime.toString("yyyy.MM.dd hh:mm:ss:zzz");
switch (type) {
case QtDebugMsg:
fprintf(stderr, "Debug: %s\n", msg.toAscii().data());
break;
case QtWarningMsg:
fprintf(stderr, "Warning: %s\n", msg.toAscii().data());
break;
case QtCriticalMsg:
fprintf(stderr, "Critical: %s\n", msg.toAscii().data());
break;
case QtFatalMsg:
fprintf(stderr, "Fatal: %s\n", msg.toAscii().data());
abort();
}
}
#endif
PS: you could add dateString to output if you want in future.
First of all, why would you need to output to console in a release mode build? Nobody will think to look there when there's a gui...
Second, qDebug is fancy :)
Third, you can try adding console to your .pro's CONFIG, it might work.
In your .pro add
CONFIG += console
It may have been an oversight of other answers, or perhaps it is a requirement of the user to indeed need console output, but the obvious answer to me is to create a secondary window that can be shown or hidden (with a checkbox or button) that shows all messages by appending lines of text to a text box widget and use that as a console?
The benefits of such a solution are:
A simple solution (providing all it displays is a simple log).
The ability to dock the 'console' widget onto the main application window. (In Qt, anyhow).
The ability to create many consoles (if more than 1 thread, etc).
A pretty easy change from local console output to sending log over network to a client.
Hope this gives you food for thought, although I am not in any way yet qualified to postulate on how you should do this, I can imagine it is something very achievable by any one of us with a little searching / reading!
Make sure Qt5Core.dll is in the same directory with your application executable.
I had a similar issue in Qt5 with a console application:
if I start the application from Qt Creator, the output text is visible,
if I open cmd.exe and start the same application there, no output is visible.
Very strange!
I solved it by copying Qt5Core.dll to the directory with the application executable.
Here is my tiny console application:
#include <QCoreApplication>
#include <QDebug>
int main(int argc, char *argv[])
{
int x=343;
QString str("Hello World");
qDebug()<< str << x<<"lalalaa";
QTextStream out(stdout);
out << "aldfjals alsdfajs...";
}
I also played with this, discovering that redirecting output worked, but I never saw output to the console window, which is present for every windows application. This is my solution so far, until I find a Qt replacement for ShowWindow and GetConsoleWindow.
Run this from a command prompt without parameters - get the window. Run from command prompt with parameters (eg. cmd aaa bbb ccc) - you get the text output on the command prompt window - just as you would expect for any Windows console app.
Please excuse the lame example - it represents about 30 minutes of tinkering.
#include "mainwindow.h"
#include <QTextStream>
#include <QCoreApplication>
#include <QApplication>
#include <QWidget>
#include <windows.h>
QT_USE_NAMESPACE
int main(int argc, char *argv[])
{
if (argc > 1) {
// User has specified command-line arguments
QCoreApplication a(argc, argv);
QTextStream out(stdout);
int i;
ShowWindow (GetConsoleWindow(),SW_NORMAL);
for (i=1; i<argc; i++)
out << i << ':' << argv [i] << endl;
out << endl << "Hello, World" << endl;
out << "Application Directory Path:" << a.applicationDirPath() << endl;
out << "Application File Path:" << a.applicationFilePath() << endl;
MessageBox (0,(LPCWSTR)"Continue?",(LPCWSTR)"Silly Question",MB_YESNO);
return 0;
} else {
QApplication a(argc, argv);
MainWindow w;
w.setWindowTitle("Simple example");
w.show();
return a.exec();
}
}
After a rather long struggle with exactly the same problem I found that simply
CONFIG += console
really does the trick. It won't work until you explicitly tell QtCreator to execute qmake on the project (right click on project) AND change something inside the source file, then rebuild. Otherwise compilation is skipped and you still won't see the output on the command line.
Now my program works in both GUI and cmd line mode.
One solution is to run powershell and redirect the output to whatever stream you want.
Below is an example of running powershell from cmd.exe and redirecting my_exec.exe output to both the console and an output.txt file:
powershell ".\my_exec.exe | tee output.txt"
An example (from cmd.exe) which holds open stdout/stderr and doesn't require tee or a temporary file:
my_exec.exe > NUL 2>&1
Easy
Step1: Create new project. Go File->New File or Project --> Other Project -->Empty Project
Step2: Use the below code.
In .pro file
QT +=widgets
CONFIG += console
TARGET = minimal
SOURCES += \ main.cpp
Step3: Create main.cpp and copy the below code.
#include <QApplication>
#include <QtCore>
using namespace std;
QTextStream in(stdin);
QTextStream out(stdout);
int main(int argc, char *argv[]){
QApplication app(argc,argv);
qDebug() << "Please enter some text over here: " << endl;
out.flush();
QString input;
input = in.readLine();
out << "The input is " << input << endl;
return app.exec();
}
I created necessary objects in the code for your understanding.
Just Run It
If you want your program to get multiple inputs with some conditions. Then past the below code in Main.cpp
#include <QApplication>
#include <QtCore>
using namespace std;
QTextStream in(stdin);
QTextStream out(stdout);
int main(int argc, char *argv[]){
QApplication app(argc,argv);
qDebug() << "Please enter some text over here: " << endl;
out.flush();
QString input;
do{
input = in.readLine();
if(input.size()==6){
out << "The input is " << input << endl;
}
else
{
qDebug("Not the exact input man");
}
}while(!input.size()==0);
qDebug(" WE ARE AT THE END");
// endif
return app.exec();
} // end main
Hope it educates you.
Good day,
First of all you can try flushing the buffer
std::cout << "Hello, world!"<<std::endl;
For more Qt based logging you can try using qDebug.