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?

Accepted Answer

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.

How to use a validator with QTableWidgetItem?

Solution

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