QT入门笔记--建立连接--connect()

末蓝、 2021-12-23 09:29 305阅读 0赞

**\#include <QApplication>  
\#include<QPushButton>  
  
int main(int argc, char \*argv\[\])  
\{  
QApplication myapp(argc, argv);  
QPushButton \*btn = new QPushButton("Quit");  
QObject::connect(btn,SIGNAL(clicked()),&myapp,SLOT(quit()));  
btn->show();  
  
 return myapp.exec();**   
**\}**

**运行结果：**

**![Center][]**

**解析：  
QPushButton：  
The QPushButton widget provides a push button with a text or pixmap label.  
  
  
QPushButton::QPushButton ( const char \* text, QWidget \* parent=0, const char \* name=0 )  
 Constructs a push button with a text.The parent and name arguments are sent to the QWidget constructor.  
  
  
QObject:  
The QObject class is the base class of all Qt objects that can deal with signals, slots and events.  
  
  
QMetaObject::Connection connect(const typename QtPrivate::FunctionPointer<Func1>::Object \*sender, Func1 signal,  
const typename QtPrivate::FunctionPointer<Func2>::Object \*receiver, Func2 slot,  
Qt::ConnectionType type = Qt::AutoConnection)  
Creates a connection of the given type from the signal in the sender object to the method in the receiver object.  
  
  
Tips:  
＊connect(sender,signal,receiver,slot)：  
通俗地解释就是，对象A发射信号（这里当用户单击QPushButton时，该按钮就会发射一个click()信号），  
对象B接到信号作出对于处理（这里QApplication接到按钮的clicked()信号，调用用quit()。）  
＊宏SIGNAL（）和SLOT（）是QT语法的一部分  
  
  
  
  
附：  
QT官网documentation中给出的connect()例子  
QLabel \*label = new QLabel;  
QLineEdit \*lineEdit = new QLineEdit;  
QObject::connect(lineEdit, &QLineEdit::textChanged,  
 label, &QLabel::setText);  
This example ensures that the label always displays the current line edit text.**

[Center]: /images/20211223/0273be0c0950413c9f13adf9c910a4c0.png