QStandardItem通过setCheckable添加复选框后无法再次通过setCheckable取消复选框的问题

前言

如题所示，通过setCheckable添加复选框后，想要通过setCheckable(false)取消复选框，你会发现根本没有作用的。

问题复现

#include "widget.h"
#include "ui_widget.h"
#include <QList>Widget::Widget(QWidget *parent) :QWidget(parent),ui(new Ui::Widget)
{ui->setupUi(this);m_model = new QStandardItemModel(this);m_model->setHorizontalHeaderLabels(QStringList() << QStringLiteral("班级/名称") << QStringLiteral("性别") << QStringLiteral("学号"));QStandardItem *class_1 = new QStandardItem(QStringLiteral("班级1"));QStandardItem *st1_name = new QStandardItem(QStringLiteral("小明"));//这个item添加复选框st1_name->setCheckable(true);QStandardItem *st1_sex = new QStandardItem(QStringLiteral("男"));QStandardItem *st1_number = new QStandardItem(QStringLiteral("1"));QStandardItem *st2_name = new QStandardItem(QStringLiteral("老王"));st2_name->setCheckable(true);QStandardItem *st2_sex = new QStandardItem(QStringLiteral("男"));QStandardItem *st2_number = new QStandardItem(QStringLiteral("2"));class_1->appendRow(QList<QStandardItem*>() << st1_name << st1_sex << st1_number);class_1->appendRow(QList<QStandardItem*>() << st2_name << st2_sex << st2_number);QStandardItem *class_2 = new QStandardItem(QStringLiteral("班级2"));QStandardItem *st3_name = new QStandardItem(QStringLiteral("小翠"));st3_name->setCheckable(true);QStandardItem *st3_sex = new QStandardItem(QStringLiteral("女"));QStandardItem *st3_number = new QStandardItem(QStringLiteral("3"));QStandardItem *st4_name = new QStandardItem(QStringLiteral("小红"));st4_name->setCheckable(true);QStandardItem *st4_sex = new QStandardItem(QStringLiteral("女"));QStandardItem *st4_number = new QStandardItem(QStringLiteral("4"));class_2->appendRow(QList<QStandardItem*>() << st3_name << st3_sex << st3_number);class_2->appendRow(QList<QStandardItem*>() << st4_name << st4_sex << st4_number);m_model->appendRow(class_1);m_model->appendRow(class_2);ui->treeView->setModel(m_model);
}Widget::~Widget()
{delete ui;
}

效果如下
在这里插入图片描述

通过 setCheckable(false) 取消复选框的设置

void Widget::on_pushButton_clicked()
{QStandardItem *item = m_model->item(0, 0)->child(0, 0);qDebug() << item->text();item->setCheckable(false);
}
经过测试发现根本没有效果。

正确的姿势

void Widget::on_pushButton_clicked()
{QStandardItem *item = m_model->item(0, 0)->child(0, 0);qDebug() << item->text();item->setData(QVariant(), Qt::CheckStateRole);
}

通过源码我们可以看到 setCheckable(true)是进行了如下操作

/*!Sets whether the item is user-checkable. If \a checkable is true, theitem can be checked by the user; otherwise, the user cannot checkthe item.The item delegate will render a checkable item with a check box next to theitem's text.\sa isCheckable(), setCheckState(), setUserTristate(), setAutoTristate()
*/
void QStandardItem::setCheckable(bool checkable)
{Q_D(QStandardItem);if (checkable && !isCheckable()) {// make sure there's data for the checkstate roleif (!data(Qt::CheckStateRole).isValid())setData(Qt::Unchecked, Qt::CheckStateRole);}d->changeFlags(checkable, Qt::ItemIsUserCheckable);
}