一.效果

1.点击下拉列表的复选框区域

2.点击下拉列表的非复选框区域

二.实现

QHCustomComboBox.h

#ifndef QHCUSTOMCOMBOBOX_H
#define QHCUSTOMCOMBOBOX_H

#include <QLineEdit>
#include <QListWidget>
#include <QCheckBox>
#include <QComboBox>
#include <QEvent>
#include <QKeyEvent>
#include <QWheelEvent>

class QHCustomComboBox: public QComboBox
{
    Q_OBJECT

public:
    explicit QHCustomComboBox(QWidget* parent = nullptr);

    void addItem(const QString &text, const QVariant &variant = QVariant());
    void addItems(const QStringList &texts);

    QStringList currentText();
    int count() const;
    void setPlaceHolderText(const QString