How to use a validator with QTableWidgetItem?

Question

Assuming I have a QTableWidgetItem item and I just wanna validate data that users enter. Example, users only enter a number into that item otherwise the program will show a warning dialog.

I also search on that document page but I didn’t find similar function with setValidator() function.

How can I use a validator for that QTableWidgetItem item?

Answer 1

Assuming what you really want is to have QValidate-able cells, you could populate the cell with a QLineEdit instance instead. Here's an example that uses QDoubleValidator, but any QValidator will work:

QLineEdit *edit = new QLineEdit(ui->myTable);
edit->setValidator(new QDoubleValidator(edit));
ui->myTable->setCellWidget(row, col, edit);

By default, QLineEdit will fill the cell and is drawn with a frame. To preserve the appearance of the table, you can turn the frame off by calling the following function a priori:

QLineEdit::setFrame(false);

One annoying thing about this solution is that you'll have to call

QWidget* QTableWidget::cellWidget(row, col) const

to subsequently access the QLineEdit instance in each cell, which means you'll have to cast the pointer to QLineEdit* also. (See qobject_cast()). It's a bit verbose but workable.