《C++ GUI Programming with Qt 4, Second Edition》讀書筆記2

Chapter 1 Getting Started / Making Connections

 

signal/slot機制

本小節講述的是QT特有的signal/slot機制。

代碼如下：

   1:  #include <QApplication>

   2:  #include <QPushButton>

   3:   

   4:  int main(int argc, char *argv[])

   5:  {

   6:      QApplication app(argc, argv);

   7:  //    QPushButton *button = new QPushButton("Quit");

   8:  //    QObject::connect(button, SIGNAL(clicked()), &app, SLOT(quit()));

   9:  //    button->show();

  10:   

  11:      QPushButton button("Quit");

  12:      QObject::connect(&button, SIGNAL(clicked()), &app, SLOT(quit()));

  13:      button.show();

  14:   

  15:      return app.exec();

  16:  }

其中，第12行是事件綁定和處理的核心代碼。

QPushButton提供的signal

Class	SIGNAL	說明
QPushButton	沒有
QAbstractButton	clicked pressed released toggled	點擊鼠標或者按下快捷鍵 按鈕被按下 按鈕被鬆開 按鈕狀態變化
QWidget	customContextMenuRequested
QObject	destroyed

 

QApplication提供的SLOT

Class	SLOT	說明
QApplication	aboutQt autoMaximizeThreshold autoSipEnabled closeAllWindows setAutoautoMaximizeThreshold setAutoSipEnabled setStyleSheet	only for Windows CE only for Windows CE only for Windows CE only for Windows CE
QCoreApplication	quit
QObject	deleteLater

 

後續工作

寫個例子來使用pressed/released/toggled信號