正在验证QTableView中的用户输入

Question

我有一个QTableView，我想验证用户输入。若用户在QTableView的单元格中插入了无效值，我想突出显示该单元格并禁用QPushButton。

我怎样才能做到这一点？我可以使用QValidator吗？

Answer 1

是的，您可以做到这一点，为此使用自定义QItemDelegate（我只是使用QIntValidator作为示例）。

标题：

#ifndef ITEMDELEGATE_H
#define ITEMDELEGATE_H
#include <QItemDelegate>
class ItemDelegate : public QItemDelegate
{
    Q_OBJECT
public:
    explicit ItemDelegate(QObject *parent = 0);
protected:
    QWidget* createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const;
    void setEditorData(QWidget * editor, const QModelIndex & index) const;
    void setModelData(QWidget * editor, QAbstractItemModel * model, const QModelIndex & index) const;
    void updateEditorGeometry(QWidget * editor, const QStyleOptionViewItem & option, const QModelIndex & index) const;
signals:
public slots:
};
#endif // ITEMDELEGATE_H

Cpp

#include "itemdelegate.h"
#include <QLineEdit>
#include <QIntValidator>
ItemDelegate::ItemDelegate(QObject *parent) :
    QItemDelegate(parent)
{
}
QWidget *ItemDelegate::createEditor(QWidget *parent,
                                    const QStyleOptionViewItem &option,
                                    const QModelIndex &index) const
{
    QLineEdit *editor = new QLineEdit(parent);
    editor->setValidator(new QIntValidator);
    return editor;
}

void ItemDelegate::setEditorData(QWidget *editor,
                                 const QModelIndex &index) const
{
    QString value =index.model()->data(index, Qt::EditRole).toString();
        QLineEdit *line = static_cast<QLineEdit*>(editor);
        line->setText(value);
}

void ItemDelegate::setModelData(QWidget *editor,
                                QAbstractItemModel *model,
                                const QModelIndex &index) const
{
    QLineEdit *line = static_cast<QLineEdit*>(editor);
    QString value = line->text();
    model->setData(index, value);
}

void ItemDelegate::updateEditorGeometry(QWidget *editor,
                                        const QStyleOptionViewItem &option,
                                        const QModelIndex &index) const
{
    editor->setGeometry(option.rect);
}

用法：

#include "itemdelegate.h"
//...
ItemDelegate *itDelegate = new  ItemDelegate;
ui->tableView->setItemDelegate(itDelegate);

在这种情况下，用户将无法输入错误的数据，但您可以使用下一个：

void ItemDelegate::setModelData(QWidget *editor,
                                QAbstractItemModel *model,
                                const QModelIndex &index) const
{
    QLineEdit *line = static_cast<QLineEdit*>(editor);
    QIntValidator validator;
    int pos = 0;
    QString data = line->text();
    if(validator.validate(data,pos) != QValidator::Acceptable)
    {
        qDebug() << "not valid";//do something
    }
    else
    {
        model->setData(index, data);
    }
}

但在这种情况下，不要忘记从代码中删除editor->setValidator(new QIntValidator);行

Answer 2

我完成了Kosovan答案的PyQt/PySide实现。我在这里为那些不使用C++的人提供了python代码：

from PySide2 import QtWidgets, QtCore, QtGui

class ItemDelegate(QtWidgets.QItemDelegate):
    def __init__(self, parent):
        super().__init__(parent)
    
    def createEditor(self, parent, option, index):
        editor = QtWidgets.QLineEdit(parent)
        editor.setValidator(QtGui.QIntValidator())
        return editor
    def setEditorData(self, editor, index):
        value = str(index.model()._data[index.row()][index.column()])
        editor.setText(value)
    
    def setModelData(self, editor, model, index):
        model.setData(index, editor.text(), QtCore.Qt.EditRole)
    
    def updateEditorGeometry(self, editor, option, index):
        editor.setGeometry(option.rect)

class TableModel(QtCore.QAbstractTableModel):
    def __init__(self, data):
        super().__init__()
        self._data = data
        
    def data(self, index, role):
        if role == QtCore.Qt.DisplayRole:
            return str(self._data[index.row()][index.column()])
    
    def rowCount(self, index):
        return len(self._data)
        
    def columnCount(self, index):
        return len(self._data[0])
    
    def setData(self, index, value, role):
        if role == QtCore.Qt.EditRole:
            try:
                value = int(value)
            except ValueError:
                return False
            self._data[index.row()][index.column()] = value
            return True
        return False
    def flags(self, index):
        return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEditable

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        
        data = [
            [1, 2], 
            [3, 4], 
            [5, 6],
        ]
        
        self.model = TableModel(data)
        
        self.table = QtWidgets.QTableView()
        self.table.setModel(self.model)
        self.table.setItemDelegate(ItemDelegate(self))
        
        self.setCentralWidget(self.table)

if __name__ == '__main__':
    app = QtWidgets.QApplication()
    win = MainWindow()
    win.show()
    app.exec_()