c++ 通过QUndoGroup实现qtreewidget和qtablewidget支持撤销与恢复功能 代码

以下是通过QUndoGroup实现QTreeWidget和QTableWidget支持撤销与恢复功能的代码示例：

#include <QtWidgets>

class TreeWidgetItem : public QTreeWidgetItem
{
public:
    explicit TreeWidgetItem(QTreeWidget *parent = nullptr)
        : QTreeWidgetItem(parent)
    {
    }

    void setData(int column, int role, const QVariant &value) override
    {
        QUndoCommand *cmd = new TreeWidgetItemDataCommand(this, column, role, text(column), value.toString());
        cmd->setText(QString("Edit %1 \"%2\" to \"%3\"").arg(parent()->objectName(), text(column), value.toString()));
        undoStack()->push(cmd);
    }

    QUndoStack *undoStack() const
    {
        return treeWidget()->property("undoStack").value<QUndoStack *>();
    }
};

class TreeWidgetItemDataCommand : public QUndoCommand
{
public:
    explicit TreeWidgetItemDataCommand(TreeWidgetItem *item, int column, int role, const QString &oldValue, const QString &newValue)
        : item(item), column(column), role(role), oldValue(oldValue), newValue(newValue)
    {
    }

    void undo() override
    {
        item->setText(column, oldValue);
    }

    void redo() override
    {
        item->setText(column, newValue);
    }

private:
    TreeWidgetItem *item;
    int column;
    int role;
    QString oldValue;
    QString newValue;
};

class TableWidgetItem : public QTableWidgetItem
{
public:
    explicit TableWidgetItem(QTableWidget *parent = nullptr)
        : QTableWidgetItem(parent)
    {
    }

    void setData(int role, const QVariant &value) override
    {
        QUndoCommand *cmd = new TableWidgetItemDataCommand(this, role, data(role), value.toString());
        cmd->setText(QString("Edit %1 \"%2\" to \"%3\"").arg(parent()->objectName(), data(Qt::DisplayRole).toString(), value.toString()));
        undoStack()->push(cmd);
    }

    QUndoStack *undoStack() const
    {
        return tableWidget()->property("undoStack").value<QUndoStack *>();
    }
};

class TableWidgetItemDataCommand : public QUndoCommand
{
public:
    explicit TableWidgetItemDataCommand(TableWidgetItem *item, int role, const QString &oldValue, const QString &newValue)
        : item(item), role(role), oldValue(oldValue), newValue(newValue)
    {
    }

    void undo() override
    {
        item->setData(role, oldValue);
    }

    void redo() override
    {
        item->setData(role, newValue);
    }

private:
    TableWidgetItem *item;
    int role;
    QString oldValue;
    QString newValue;
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QUndoGroup undoGroup;

    // 创建 QTreeWidget
    QTreeWidget treeWidget;
    treeWidget.setObjectName("TreeWidget");
    treeWidget.setProperty("undoStack", QVariant::fromValue(&undoGroup.createUndoStack()));

    // 创建 QTableWidget
    QTableWidget tableWidget;
    tableWidget.setObjectName("TableWidget");
    tableWidget.setProperty("undoStack", QVariant::fromValue(&undoGroup.createUndoStack()));
    tableWidget.setColumnCount(2);
    tableWidget.setRowCount(2);

    // 添加测试数据
    treeWidget.setHeaderLabels({"Name", "Value"});
    QTreeWidgetItem *root = new QTreeWidgetItem(&treeWidget, {"Root"});
    TreeWidgetItem *child1 = new TreeWidgetItem(root);
    child1->setText(0, "Child 1");
    child1->setText(1, "1");
    TreeWidgetItem *child2 = new TreeWidgetItem(root);
    child2->setText(0, "Child 2");
    child2->setText(1, "2");
    tableWidget.setItem(0, 0, new TableWidgetItem(&tableWidget));
    tableWidget.setItem(0, 1, new TableWidgetItem(&tableWidget));
    tableWidget.setItem(1, 0, new TableWidgetItem(&tableWidget));
    tableWidget.setItem(1, 1, new TableWidgetItem(&tableWidget));

    // 创建一个窗口并显示
    QMainWindow window;
    window.setCentralWidget(&treeWidget);
    window.setMenuBar(new QMenuBar);
    window.menuBar()->addAction(undoGroup.createUndoAction(&window));
    window.menuBar()->addAction(undoGroup.createRedoAction(&window));
    window.show();

    return app.exec();
}

在上面的代码中，我们创建了两个自定义的QTreeWidgetItem和QTableWidgetItem类，用于处理数据更改操作。这些类都继承了QUndoCommand类，以便我们可以将更改操作添加到QUndoStack中。

我们还使用QTreeWidget和QTableWidget的setProperty方法将undoStack属性设置为创建的QUndoStack对象。这使得我们可以通过使用undoStack()方法来获取当前对象的QUndoStack对象。

最后，我们创建了一个窗口并将其显示出来。我们将撤销和重做操作添加到菜单栏中，以便用户可以轻松地撤销和恢复更改操作。