QFileSystemModel/TreeView - issues

[jacob.n]

Hello there!
I'm experienced in C/C++, php.
Watched a lot of vids about QT, read 70% of 1 QT book.

Important book part can not handle without your kind support:

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFileSystemModel>
MainWindow::MainWindow(QWidget *parent)
Creating a simple Qt Widgets application using the M/V pattern
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
QFileSystemModel *model = new QFileSystemModel;
model->setRootPath(QDir::currentPath());
ui->treeView->setModel(model);
ui->treeView->setRootIndex(
model->index(QDir::currentPath()));
ui->listView->setModel(model);
ui->listView->setRootIndex(
model->index(QDir::currentPath()));
}
Getting error above

D:\prog\output1\output1\mainwindow.cpp:15: error: 'class Ui::MainWindow' has no member named 'treeView'
..\output1\mainwindow.cpp:15:9: error: 'class Ui::MainWindow' has no member named 'treeView'
15 | ui->treeView->setRootIndex(
| ^~~~~~~~

[JonB]

@jacob-n said in QFileSystemModel/TreeView - issues:

'class Ui::MainWindow' has no member named 'treeView'

What is there to say other than you do not have a QTreeView/QWidget named treeview?

[jacob.n]

What do I need to share?

I have MainWindow and header + cpp file for it, also I have ui.
Need to compile

[jsulm]

@jacob-n Ui::MainWindow does not have an attribute called treeView, this is what the error clearly tells you.
Are you sure you added treeView in your ui file?

[jacob.n]

Just figured it out after your post...
Added, previous error solved, now having another errors:
:-1: error: release/main.o:main.cpp:(.text+0x55): undefined reference to MainWindow::~MainWindow()' :-1: error: release/moc_mainwindow.o:moc_mainwindow:(.rdata$_ZTV10MainWindow[_ZTV10MainWindow]+0x28): undefined reference to MainWindow::~MainWindow()'

[J.Hilk]

@jacob-n do you have a function body to your ~MainWindow() somewhere?

[jacob.n]

@J-Hilk
Might be here in header?

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();

private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

[J.Hilk]

@jacob-n nope, like the compiler I only see the function declaration

[JonB]

@jacob-n
Exactly as @J-Hilk says. If you have the method declaration ~MainWindow(); in the class header you must supply the method definition/implementation somewhere, e.g. in the .cpp.

[jacob.n]

As I posted mainwindow.h and mainwindow.cpp, there is only last available option - main.cpp
Seems ok for me, but still in QT for 130 hours, still lacking a lot of basic syntax..

Please give me the lead, folks :D

#include "mainwindow.h"

#include <QApplication>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}

[JonB]

@jacob-n said in QFileSystemModel/TreeView - issues:

Seems ok for me, but still in QT for 130 hours, still lacking a lot of basic syntax..

You said earlier "I'm experienced in C/C++, php.". This issue has nothing to do with Qt, or its syntax (which it does not have as it is not a language). It is just standard, basic C++.

As I posted mainwindow.h and mainwindow.cpp, there is only last available option - main.cpp

No this has nothing to do with main.cpp.

In your first post you showed the body of mainwindow.cpp. Where does that provide the definition for MainWindow::~MainWindow()?

[jacob.n]

Here, constructor and desctructor

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
}

MainWindow::~MainWindow()
{
delete ui;
}

[JonB]

@jacob-n
OK, but that MainWindow::~MainWindow() was not in what you posted earlier, was it? Given that, if you recompile now you should not get the undefined reference to MainWindow::~MainWindow() error that you showed earlier?

[jacob.n]

Yeah, fixed that one. Thank you!
Can you please help with next issue, I found how to save data to kind of table and output.
Please advise alternative way to output data from array without saving into temporary table.
#include "Dialog.h"
#include "ui_Dialog.h"

Dialog::Dialog(QWidget *parent)
: QDialog(parent)
, ui(new Ui::Dialog)
{
ui->setupUi(this);

model = new QStandardItemModel(5,2, this);

ui->tableView->setModel(model);
QModelIndex index;

for (int row = 0; row < model->rowCount(); ++row)
{
   for (int col = 0; col < model ->columnCount(); ++col)
   {
      index = model->index (row,col);
      model->setData(index,9);
   }

}

}

Dialog::~Dialog()
{
delete ui;
}

Thanks in advance,
Jacob N

[JonB]

@jacob-n
Your code just shows putting some data into the model. I don't know what you mean by "output data" and where a "temporary table" is involved.

If you mean you don't need/want the data storage provided by a QStandardItemModel, e.g. you have your own data in an array, look at QAbstractTableModel Class and the Subclassing section instead. All you have to do is

When subclassing QAbstractTableModel, you must implement rowCount(), columnCount(), and data().

Just tie those to your array.

Editable models need to implement setData(), and implement flags() to return a value containing Qt::ItemIsEditable.

And implement setData() to write into your array.

Once you have that you can replace the QStandardItemModel with it and the QTableView will work the same but use your array as the model.

[jacob.n]

Hello there!

qDebug() << ui->tableView->model()->index(0,0).data();
outputting to console this:
QVariant(int, 1)
I just need to return to function this int value.

like
return ui->tableView->model()->index(0,0).data();
return tableView.getData(something);

What is the proper syntax ?

BR

Jacob

[jsulm]

@jacob-n said in QFileSystemModel/TreeView - issues:

I just need to return to function this int value

https://doc.qt.io/qt-5/qvariant.html#toInt

[icebergenergy]

This post is deleted!

[jacob.n]

is there a way to convert from QVariant to std string?

[Christian Ehrlicher]

@jacob-n said in QFileSystemModel/TreeView - issues:

is there a way to convert from QVariant to std string?

Convert it to a QString and then to a std::string.