qt5之下拉列表框QComboBox

桃扇骨 2022-03-11 06:22 1229阅读 0赞

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）addItems  
　　void addItem(const QString &text, const QVariant &userData = QVariant())  
　　void addItem(const QIcon &icon, const QString &text, const QVariant &userData = QVariant())  
（2）currentText 在列表的最后一项添加一个文本内容为test选项  
　　 QString currentText() const　　返回下拉列表框中当前选中的文本  
（3）count　int count() const　返回当前列表框中选项数量  
（4）currentIndex 　int currentIndex() const　返回当前列表框中选中文本的序号

//mydialog.h
    #ifndef MYDIALOG_H
    #define MYDIALOG_H
    #include <QDialog>
    class QComboBox;
    class MyDialog : public QDialog
    {
      Q_OBJECT
    public:
      explicit MyDialog(QWidget *parent = 0);
    signals:
    public slots:
      void onChanged(int index);
    private:
      QComboBox *comboBox;
    };
    #endif

//mydialog.cpp

#include "mydialog.h"
    #include <QComboBox>
    #include <QLayout>
    #include <QDebug>
     
    MyDialog::MyDialog(QWidget *parent) :
      QDialog(parent)
    {
        combobox = new QComboBox(this);
        combobox ->setGeometry(50,50,200,300);
        combobox->addItem(tr("Circle"));
        combobox->addItem(tr("Pology"));
        
        //利用重写向combobox加入图标
        combobox->addIteam(QIcon("\home\ttang\1.png"),"circle");
        combobox->addIteam(QIcon("\home\ttang\3.png"),"Pology");
        QGridLayout *mainLayout = new QGridLayout(this);  //网络布局
        mainLayout->addWidget(combobox,0,0);
        
       connect(combobox,SIGNAL(currentIndexChanged(int)),this,SLOT(valueChanged()));
       
        qDebug() << "Now there are " << combobox->count() << "Items";
        qDebug() << "The current item is" << combobox->currentText();
    }
     
    void MyDialog::valueChanged()
    {
        int currentIndex = combo->currentIndex();
        QString currentText = combo->currentText();
        qDebug()<<currentIndex<<currentText;
    }
    
    Widget::~Widget()
    {
    }

//main.cpp
    #include <QtGui/QApplication> 
    #include "mydialog.h"
     
    int main(int argc, char *argv[]) 
    {
     
      QApplication a(argc, argv);
     
      MyDialog dialog;
     
      dialog.show();
     
      return a.exec();
     
    }