using the slot setText(const QString &text)

[Zunneh]

Hello guys ,
i want to use the slot setText(const QString &text)

         QObject::connect(ui->treeWidget,SIGNAL(itemSelectionChanged()),ui->textEdit,SLOT(setText(const QString &text)));

where can i put the text to display in my QTextEdit ? Thanks guys

[VRonin]

just create a slot or a lambda that decides what text to write:

QObject::connect(ui->treeWidget->selectionModel(),&QItemSelectionModel::SelectionChanged,ui->textEdit,[this](const QItemSelection &selected)->void{
const auto selectedIndexes = selected.indexes();
QString newText;
for(auto&& idx : selectedIndexes)
newText += idx.data().toString() + QLatin1Char(';');
ui->textEdit.setText(newText);
});

[Zunneh]

@VRonin i didn't understand the code , are there a solution more easy ? i past your code , i have error (expected expression)

[VRonin]

are there a solution more easy ?

create a private slots: in your class called updateText() then use QObject::connect(ui->treeWidget,SIGNAL(itemSelectionChanged()),this,SLOT(updateText()));
Inside updateText then you can call ui->textEdit->setText() with whaterver argument you like

[Zunneh]

@VRonin i want to keep the 3rd parameter of connect ui->textEdit , i tried this the last idea you mention and it work , now i want to try with keeping ui->textEdit

[JonB]

@Zunneh
@VRonin's original code uses a C++ lambda --- effectively, a function defined in-line --- as the slot in the call to QObject::connect(). Lambda syntax can be a bit intimidating...!

As per his second suggestion, you can instead simply write your own slot function and call that, which has a syntax you are perhaps more used to.

[VRonin]

@Zunneh said in using the slot setText(const QString &text):

i want to keep the 3rd parameter of connect ui->textEdit

I honestly have no idea why you would want that.

[J.Hilk]

@Zunneh said in using the slot setText(const QString &text):

@VRonin i want to keep the 3rd parameter of connect ui->textEdit , i tried this the last idea you mention and it work , now i want to try with keeping ui->textEdit

than either use @VRonin first example or define yourself a signal that has a QString as argument and connect that to your textEdit updateText setText slot

[Zunneh]

@VRonin because i my big project i tried with this , it didn't work ,i tried it in sample project it work (i don't konw why ) i have to use the name of my object to do it , meanwhile i don't know how to create signal , i have to detect if itemSelectionChanged() of my QtreeWidget then display text , the only way is setText(const QString &text) but i don't know how to manipulate it , i have to create a signal to send the text ?

[Zunneh]

@VRonin your idea works finaly , thank you guys , i search in internet and i added

     CONFIG += c++11

to use lambda

 QObject::connect(ui->treeWidget- >selectionModel(),&QItemSelectionModel::SelectionChanged,ui->textEdit,[this](const QItemSelection &selected)->void{
  const auto selectedIndexes = selected.indexes();
 QString newText;
 for(auto&& idx : selectedIndexes)
 newText += idx.data().toString() + QLatin1Char(';');
 ui->textEdit->setText(newText);
  });

i modified your code to make it more lisible

   QObject::connect(ui->treeWidget- >selectionModel(),&QItemSelectionModel::selectionChanged,ui->textEdit,[this]()->void{

QString test;
test=ui->treeWidget->currentItem()->text(ui->treeWidget->currentColumn());

ui->textEdit->setText(test);
});