QComboxBox 下拉列表
1.属性:编辑，图标大小
2.插入数据(字符串，图标，自定义数据)
3.读取删除数据
4.信号事件

QComboBox新曾数据

1.void addItem(const QString &text,const QVariant &userData = QVariant());
2.void addItem(const QIcon &icon, const QString &text, const QVariant &userData = QVariant());
3.void addItem(const QStringList &texts);

QComboBox 插入数据

1.void insertItems(int index,const QStringList &list);
2.void insertItem(int index,const QString &text, const QVariant &userData = QVariant());
3.void insertItem(int index,const QIcon &icon, const QString &text,const QVariant &userData = QVariant());

QComboBox删除数据

1.void removeItem(int index)
2.[slot] void QComboBox::clearEditText()
3.[slot] void QComboBox::clear()

ui_widget.h

#ifndef UI_WIDGET_H
#define UI_WIDGET_H#include <QtCore/QVariant>
#include <QtWidgets/QApplication>
#include <QtWidgets/QComboBox>
#include <QtWidgets/QWidget>QT_BEGIN_NAMESPACEclass Ui_Widget
{
public:QComboBox *comboBox;void setupUi(QWidget *Widget){if (Widget->objectName().isEmpty())Widget->setObjectName(QString::fromUtf8("Widget"));Widget->resize(800, 600);comboBox = new QComboBox(Widget);comboBox->addItem(QString());comboBox->addItem(QString());QIcon icon;icon.addFile(QString::fromUtf8("Resources/test.png"), QSize(), QIcon::Normal, QIcon::Off);comboBox->addItem(icon, QString());comboBox->setObjectName(QString::fromUtf8("comboBox"));comboBox->setGeometry(QRect(180, 120, 441, 101));comboBox->setEditable(true);comboBox->setIconSize(QSize(50, 50));retranslateUi(Widget);QMetaObject::connectSlotsByName(Widget);} // setupUivoid retranslateUi(QWidget *Widget){Widget->setWindowTitle(QCoreApplication::translate("Widget", "Widget", nullptr));comboBox->setItemText(0, QCoreApplication::translate("Widget", "test1", nullptr));comboBox->setItemText(1, QCoreApplication::translate("Widget", "\346\265\213\350\257\2252", nullptr));comboBox->setItemText(2, QCoreApplication::translate("Widget", "test3", nullptr));} // retranslateUi};namespace Ui {class Widget: public Ui_Widget {};
} // namespace UiQT_END_NAMESPACE#endif // UI_WIDGET_H

widget.cpp

#include "widget.h"
#include "ui_widget.h"Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);ui->comboBox->clear();ui->comboBox->addItem("Item001");ui->comboBox->addItem("Item002");//图标QIcon icon("./Resources/test.png");ui->comboBox->addItem(icon,"Item003");ui->comboBox->clear();QStringList lst = {"test1","test2","test3"};ui->comboBox->addItems(lst);ui->comboBox->insertItem(1,"test");
}Widget::~Widget()
{delete ui;
}