QT控件之QComboBox（下拉框相关）

QComboBox提供了下拉列表框的控件。下面简单介绍几个的方法和属性。（1）addItemsvoid addItem(const QString &text, const QVariant &userData = QVariant())void addItem(const QIcon &icon, const QString &text, const QVariant &userData = QVariant())在列表的最后一项添加一个文本内容为test选项（2）currentTextQString currentText() const返回下拉列表框中当前选中的文本（3）countint count() const返回当前列表框中选项数量（4）currentIndexint currentIndex() const返回当前列表框中选中文本的序号简单的案例：#include "widget.h"#include <QComboBox>#include <QLayout>#include <QDebug>Widget::Widget(QWidget *parent): QWidget(parent){QComboBox *combobox = new QComboBox(this);combobox->addItem(tr("Circle"));combobox->addItem(tr("Pology"));QGridLayout *mainLayout = new QGridLayout(this);mainLayout->addWidget(combobox,0,0);qDebug() << "Now there are " << combobox->count() << "Items";qDebug() << "The current item is" << combobox->currentText();}Widget::~Widget(){}

结果：

程序输出：

Now there are 2 ItemsThe current item is "Circle"

代码2：

//不带图标写法ui->comboBox->addItem("A1");ui->comboBox->addItem("A2");ui->comboBox->addItem("A3");ui->comboBox->addItem("A4");ui->comboBox->addItem("A5");ui->comboBox->addItem("A6");//带图标写法ui->comboBox->addItem(icon,QString::asprintf("Item %d",i)); //可以使用QStringList 一次写入多个数据QStringList strList;strList<<"A1"<<"A2"<<"A3"<<"A4"<<"A5"<<"A6";ui->comboBox->addItems(strList);

ui->comboBox->setCurrentIndex(2);

获取ComboBox控件总索引数//索引为1-6int intc = ui->comboBox->count();QString StrIntN=QString::number(intc);QMessageBox::information(this, "comboBox", StrIntN, QMessageBox::Ok);

获取ComboBox控件当前选中索引：//索引为0-5int index = ui->comboBox->currentIndex();//获得索引QString StrIntN=QString::number(index);QMessageBox::information(this, "comboBox", StrIntN, QMessageBox::Ok);

获取当前内容：QMessageBox::information(this, "comboBox", ui->comboBox->currentText(), QMessageBox::Ok);

ui->comboBox->clear(); //清除列表