核心思想：
void QComboBox::setView(QAbstractItemView *itemView)
void QComboBox::setModel(QAbstractItemModel *model)
下拉列表拉出来的那个界面可以是 QAbstractItemView ，比如QListWidget 。只要在构造函数中：
QComboBox->setModel(pListWidget->model());
QComboBox->setView(pListWidget);
设置好其他的操作就和 QListWidget 一样了。
所以 我们想要在下拉列表里加入复选框，只需要设置
QListWidgetItem *pItem = new QListWidgetItem(pListWidget);
pListWidget->addItem(pItem);
QCheckBox *pCheckBox = new QCheckBox(this);
pCheckBox->setText(value);
pListWidget->addItem(pItem);
pListWidget->setItemWidget(pItem, pCheckBox);
connect(pCheckBox, SIGNAL(stateChanged(int)), this, SLOT(Slot_StateChanged(int)));
即可。
同理，下拉列表还可以是表格形式
源码
#pragma once
#include <qcombobox.h>
#include<QListWidget>
#include<QLineEdit>
class CheckComboBox:
public QComboBox
{
Q_OBJECT
public:
CheckComboBox(QWidget * parent = nullptr);
~CheckComboBox();
void setValues(QStringList values);
void push_back(QString value);
QString text();//返回用户选择的值
protected slots:
void Slot_StateChanged(int);
private:
QListWidget *pListWidget = nullptr;
QLineEdit *pLineEdit = nullptr;
BASEINFO m_strInfo;
};
#include "CheckComboBox.h"
#include "QCheckBox"
CheckComboBox::CheckComboBox(QWidget * parent ) :QComboBox(parent)
{
pListWidget = new QListWidget(this);
pLineEdit = new QLineEdit(this);
this->setModel(pListWidget->model());
this->setView(pListWidget);
this->setLineEdit(pLineEdit);
pLineEdit->setReadOnly(true);
}
CheckComboBox::~CheckComboBox()
{
if (pListWidget)
{
delete pListWidget;
pListWidget = nullptr;
}
if (pLineEdit)
{
delete pLineEdit;
pLineEdit = nullptr;
}
}
void CheckComboBox::setValues(QStringList values)
{
for (auto value : values)
{
push_back(value);
}
}
void CheckComboBox::push_back(QString value)
{
QListWidgetItem *pItem = new QListWidgetItem(pListWidget);
pListWidget->addItem(pItem);
QCheckBox *pCheckBox = new QCheckBox(this);
pCheckBox->setText(value);
pListWidget->addItem(pItem);
pListWidget->setItemWidget(pItem, pCheckBox);
connect(pCheckBox, SIGNAL(stateChanged(int)), this, SLOT(Slot_StateChanged(int)));
pCheckBox->setChecked(true);
}
void CheckComboBox::Slot_StateChanged(int)
{
QString strSelectedData;
int nCount = pListWidget->count();
for (int i = 0; i < nCount; ++i)
{
QListWidgetItem *pItem = pListWidget->item(i);
QWidget *pWidget = pListWidget->itemWidget(pItem);
QCheckBox *pCheckBox = (QCheckBox *)pWidget;
if (pCheckBox->isChecked())
{
QString strText = pCheckBox->text();
strSelectedData.append(strText).append(";");
}
}
//避免最后一个item添加";"
if (strSelectedData.endsWith(";"))
strSelectedData.remove(strSelectedData.count() - 1, 1);
if (!strSelectedData.isEmpty())
{
pLineEdit->setText(strSelectedData);
pLineEdit->setToolTip(strSelectedData);
}
}
QString CheckComboBox::text()
{
return pLineEdit->text();
}