Connecting two windows
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@JonB Thank you.
&MainWindow::patientID
is a signal which is emitted asemit patientID(selection[0].data().toString());
So I need to
setText
label in another window (StageOne
). The text isselection[0].data().toString()
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I tried this:
connect(this, &MainWindow::patientID, ui->label, &QLabel::setText);
this throws a different error:
stageone.cpp:11:5: error: no matching member function for call to 'connect' qobject.h:228:43: note: candidate function [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] not viable: no known conversion from 'StageOne *' to 'const typename QtPrivate::FunctionPointer<void (MainWindow::*)(QString)>::Object *' (aka 'const MainWindow *') for 1st argument qobject.h:208:36: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const char *' for 2nd argument qobject.h:211:36: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const QMetaMethod' for 2nd argument qobject.h:463:41: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const char *' for 2nd argument qobject.h:269:13: note: candidate template ignored: requirement '!QtPrivate::FunctionPointer<void (QLabel::*)(const QString &)>::IsPointerToMemberFunction' was not satisfied [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] qobject.h:308:13: note: candidate template ignored: requirement 'QtPrivate::FunctionPointer<void (QLabel::*)(const QString &)>::ArgumentCount == -1' was not satisfied [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] qobject.h:260:13: note: candidate function template not viable: requires 3 arguments, but 4 were provided qobject.h:300:13: note: candidate function template not viable: requires 3 arguments, but 4 were provided
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@russjohn834
I would suggest thatpatientID
is not at all a good name for a signal or a method! Something more likepatientIdChanged
would be usual and intelligible.The error message is complaining about your first parameter,
&MainWindow
. I don't know what you think that is. As I said, you probably meanthis
there. -
@russjohn834
In answer to your new messages, when you wrote earlier&MainWindow::patientID is a signal which is emitted as
emit patientID(selection[0].data().toString());
this is not good enough for people to help you, I would suggest. We need to see the definition in the
.cpp
file and the declaration in the.h
file.... -
@russjohn834 Please show the exact declaration of patientID...
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@jsulm Hi,
I declared
patientID
as:QT_BEGIN_NAMESPACE namespace Ui { class MainWindow; } QT_END_NAMESPACE class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(QWidget *parent = nullptr); ~MainWindow(); StageTwoNew *stagetwonew; StageOne *stageone; signals: void patientID(QString); ----------------> signal declaration public slots: void on_pushButton_New_clicked(); void on_pushButton_Open_clicked(); void parseDataEntry(const QString dataPath); private: Ui::MainWindow *ui; }; #endif // MAINWINDOW_H
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@russjohn834 Looks good. Try a complete rebuild: delete build folder, run qmake and then build.
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I'm getting still the same error:
stageone.cpp:11:5: error: no matching member function for call to 'connect' qobject.h:228:43: note: candidate function [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] not viable: no known conversion from 'StageOne *' to 'const typename QtPrivate::FunctionPointer<void (MainWindow::*)(QString)>::Object *' (aka 'const MainWindow *') for 1st argument qobject.h:208:36: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const char *' for 2nd argument qobject.h:211:36: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const QMetaMethod' for 2nd argument qobject.h:463:41: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const char *' for 2nd argument qobject.h:269:13: note: candidate template ignored: requirement '!QtPrivate::FunctionPointer<void (QLabel::*)(const QString &)>::IsPointerToMemberFunction' was not satisfied [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] qobject.h:308:13: note: candidate template ignored: requirement 'QtPrivate::FunctionPointer<void (QLabel::*)(const QString &)>::ArgumentCount == -1' was not satisfied [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] qobject.h:260:13: note: candidate function template not viable: requires 3 arguments, but 4 were provided qobject.h:300:13: note: candidate function template not viable: requires 3 arguments, but 4 were provided
This is how I call the connect:
#include "stageone.h" #include "ui_stageone.h" #include "mainwindow.h" StageOne::StageOne(QWidget *parent) : QMainWindow(parent), ui(new Ui::StageOne) { ui->setupUi(this); connect(this, &MainWindow::patientID, ui->label, &QLabel::setText); // }
Any idea?
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do you happen to have a function body inside mainwindow.cpp ?
somethinglike:
void MainWindow::patientID(QString string)That's not allowed for signals
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@russjohn834 said in Connecting two windows:
connect(this, &MainWindow::patientID, ui->label, &QLabel::setText);
Oh its much simpler
You class is not called MainWindow, but StageOne
connect(this, &StageOne::patientID, ui->label, &QLabel::setText);
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@J-Hilk @russjohn834 I'm lost. The signal is declared in MainWindow, but connect is in StageOne.
@russjohn834 What is it now?! -
Still the same issue.
I changed the name of signal from
patientID
topatientIdChanged
.signal is Declared and emitted in
MainWindow
. Connection is inStageOne
(with a QLabel).StageOne::StageOne(QWidget *parent) : QMainWindow(parent), ui(new Ui::StageOne) { ui->setupUi(this); connect(this, &MainWindow::patientIdChanged, ui->label, &QLabel::setText); // }
the error says:
stageone.cpp:11:5: error: no matching member function for call to 'connect' qobject.h:228:43: note: candidate function [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] not viable: no known conversion from 'StageOne *' to 'const typename QtPrivate::FunctionPointer<void (MainWindow::*)(QString)>::Object *' (aka 'const MainWindow *') for 1st argument qobject.h:208:36: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const char *' for 2nd argument qobject.h:211:36: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const QMetaMethod' for 2nd argument qobject.h:463:41: note: candidate function not viable: no known conversion from 'void (MainWindow::*)(QString)' to 'const char *' for 2nd argument qobject.h:269:13: note: candidate template ignored: requirement '!QtPrivate::FunctionPointer<void (QLabel::*)(const QString &)>::IsPointerToMemberFunction' was not satisfied [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] qobject.h:308:13: note: candidate template ignored: requirement 'QtPrivate::FunctionPointer<void (QLabel::*)(const QString &)>::ArgumentCount == -1' was not satisfied [with Func1 = void (MainWindow::*)(QString), Func2 = void (QLabel::*)(const QString &)] qobject.h:260:13: note: candidate function template not viable: requires 3 arguments, but 4 were provided qobject.h:300:13: note: candidate function template not viable: requires 3 arguments, but 4 were provided
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@russjohn834 Come on it is not about patientID!
In the connect bellow this is NOT MainWindow, but StageOne!
It simply can't work this way!StageOne::StageOne(QWidget *parent) : QMainWindow(parent), ui(new Ui::StageOne) { ui->setupUi(this); connect(this, &MainWindow::patientIdChanged, ui->label, &QLabel::setText); // this != MaiNWindow*! }
If you want to connect in StageOne then you need an instance of MainWindow:
StageOne::StageOne(QWidget *parent) : QMainWindow(parent), ui(new Ui::StageOne) { ui->setupUi(this); MainWindow *mainWindow = new MainWindow(...); connect(mainWindow, &MainWindow::patientIdChanged, ui->label, &QLabel::setText); // this != MaiNWindow*! }
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@jsulm
This is partly due to my bad... :(No declaration of
StageOne
was shown. I quickly read:StageOne::StageOne(QWidget *parent) : QMainWindow(parent)
I read it too quickly, and thought
StageOne
was derived fromQMainWindow
. Comes from doing Python all the time instead of C++. So I misled OP by saying put inthis
where he should havemainWindow
, my fault not his! -
I'm a bit lost!
I now get a different error
mainwindow.h:25: error: C2143: syntax error: missing ';' before '*' mainwindow.h:25: error: C4430: missing type specifier - int assumed. Note: C++ does not support default-int mainwindow.h:25: error: C2238: unexpected token(s) preceding ';'
this is my mainwindow.h
#ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QMainWindow> #include <QDebug> #include <QFile> #include <QDirIterator> #include <QXmlStreamReader> #include <QMessageBox> #include "stagetwonew.h" #include "stageone.h" QT_BEGIN_NAMESPACE namespace Ui { class MainWindow; } QT_END_NAMESPACE class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(QWidget *parent = nullptr); ~MainWindow(); StageTwoNew *stagetwonew; StageOne *stageone; ------------------>error points here signals: void patientIdChanged(QString); private slots: void on_pushButton_New_clicked(); void on_pushButton_Open_clicked(); void parseDataEntry(const QString dataPath); private: Ui::MainWindow *ui; }; #endif // MAINWINDOW_H
I tried complete rebuild, no luck
Any ideas where I'm wrong?
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#include "stagetwonew.h" #include "stageone.h" ... StageTwoNew *stagetwonew; StageOne *stageone; ------------------>error points here
Prove to us/yourself that those two header files declare
StageTwoNew
&StageOne
as classes? (Having said that, I'd more have expected "undeclared", but at least check what I've said, even if I did mis-lead you earlier :) ) -
@JonB said in Connecting two windows:
I read it too quickly, and thought StageOne was derived from QMainWindow
It apparently is derived from QMainWindow, but this does not have anything to do with your MainWindow.
Does StageOne include mainwindow.h? If so you have circular dependency. -
@jsulm said in Connecting two windows:
Does StageOne include mainwindow.h? If so you have circular dependency.
Yes. StageOne inlcude mainwindow.h. Any suggestion, How do I go about with circular dependency in this scenario?
Or is there a better way to do this (connect between two forms (
QMainWindow
))? -
@russjohn834 could you please state your requirement again?
How are the window(s) suppose to work together?
What data you want from what window updating what widget in what other window? -
@Pablo-J-Rogina Hi,
There are two forms.
MainWindow
andStageOne
(Both inherits QMainWindow).MainWindow
has a signalpatientIdChanged(QString)
, which is emitted upon clicking a button, I did this:void MainWindow::on_pushButton_Open_clicked() { QModelIndexList selection=ui->tableWidget->selectionModel()->selectedRows(0); this->hide(); stageone = new StageOne(this); stageone->show(); emit patientIdChanged(selection[0].data().toString()); }
And in
StageOne
I have aQLabel
, itssetText
should get signal (Qstring) value fromMainwWndow
and show. That's the requirement.I tried to do this in
StageOne
:MainWindow *mainWindow= new MainWindow(this); connect(mainWindow, &MainWindow::patientIdChanged, ui->label, &QLabel::setText);
But this is not working