QT练习4:编写一个查找对话框

分为3个文件:

finddialog.h:

  
    

   
     #ifndef FINDDIALOG_H

   
     #define
   
      FINDDIALOG_H
   
     

#include 
   
     <
   
     QDialog
   
     >
   
     


   
     class
   
      QCheckBox;

   
     class
   
      QLabel;

   
     class
   
      QLineEdit;

   
     class
   
      QPushButton;


   
     //
   
     自定义类,继承于QDialog
   
     

   
     class
   
      FindDialog:
   
     public
   
      QDialog
{
 Q_OBJECT

   
     public
   
     :
 FindDialog(QWidget 
   
     *
   
     parent
   
     =
   
     0
   
     );
   
     //
   
     构造函数
   
     

   
     
signals:
 
   
     void
   
      findNext(
   
     const
   
      QString 
   
     &
   
     str,
   
     bool
   
      caseSensitive);
 
   
     void
   
      findPrev(
   
     const
   
      QString 
   
     &
   
     str,
   
     bool
   
      caseSensitive);

   
     private
   
      slots:
   
     //
   
     私有槽
   
     

   
      
   
     void
   
      findClicked();
 
   
     void
   
      enableFindButton(
   
     const
   
      QString 
   
     &
   
     text);


   
     private
   
     :
 
   
     //
   
     声明窗口要使用到的部件
   
     

   
      QLabel 
   
     *
   
     label;
 QLineEdit 
   
     *
   
     lineEdit;
 QCheckBox 
   
     *
   
     caseCheckBox;
 QCheckBox 
   
     *
   
     backwardCheckBox;
 QPushButton 
   
     *
   
     findButton;
 QPushButton 
   
     *
   
     closeButton;

};


   
     #endif
   
      
   
     //
   
      FINDDIALOG_H
  
    

finddialog.cpp

  
    

   
     #include 
   
     <
   
     QCheckBox
   
     >
   
     
#include 
   
     <
   
     QLabel
   
     >
   
     
#include 
   
     <
   
     QLayout
   
     >
   
     
#include 
   
     <
   
     QLineEdit
   
     >
   
     
#include 
   
     <
   
     QPushButton
   
     >
   
     

#include 
   
     "
   
     finddialog.h
   
     "
   
     

FindDialog::FindDialog(QWidget 
   
     *
   
     parent)
 :QDialog(parent)
   
     //
   
     对父类进行构造
   
     

   
     {
 label 
   
     =
   
      
   
     new
   
      QLabel(tr(
   
     "
   
     Find &what:
   
     "
   
     ),
   
     this
   
     );
 lineEdit 
   
     =
   
      
   
     new
   
      QLineEdit(
   
     "
   
     wenhao
   
     "
   
     ,
   
     this
   
     );
 label
   
     ->
   
     setBuddy(lineEdit);
   
     //
   
     label,lineEdit是伙伴关系.按label的快捷键进入lineEdit中
   
     

   
     

 caseCheckBox 
   
     =
   
      
   
     new
   
      QCheckBox(tr(
   
     "
   
     Match &case
   
     "
   
     ),
   
     this
   
     );
 backwardCheckBox 
   
     =
   
      
   
     new
   
      QCheckBox(tr(
   
     "
   
     Search &backward
   
     "
   
     ),
   
     this
   
     );

 findButton 
   
     =
   
      
   
     new
   
      QPushButton(tr(
   
     "
   
     &Find
   
     "
   
     ),
   
     this
   
     );
 findButton
   
     ->
   
     setDefault(
   
     true
   
     );
   
     //
   
     接回车键相当于按下findButton键
   
     

   
      findButton
   
     ->
   
     setEnabled(
   
     false
   
     );
   
     //
   
     这个设置让其默认是不可以点击的.
   
     

   
     
 closeButton 
   
     =
   
      
   
     new
   
      QPushButton(tr(
   
     "
   
     Close
   
     "
   
     ),
   
     this
   
     );
 connect(lineEdit,SIGNAL(textChanged(
   
     const
   
      QString 
   
     &
   
     )),
 
   
     this
   
     ,SLOT(enableFindButton(
   
     const
   
      QString 
   
     &
   
     )));
 connect(findButton,SIGNAL(clicked()),
   
     this
   
     ,SLOT(findClicked()));
 connect(closeButton,SIGNAL(clicked()),
   
     this
   
     ,SLOT(close()));

 QHBoxLayout 
   
     *
   
     topLeftLayout 
   
     =
   
      
   
     new
   
      QHBoxLayout;
 topLeftLayout
   
     ->
   
     addWidget(label);
 topLeftLayout
   
     ->
   
     addWidget(lineEdit);

 QVBoxLayout 
   
     *
   
     leftLayout 
   
     =
   
      
   
     new
   
      QVBoxLayout;
 leftLayout
   
     ->
   
     addLayout(topLeftLayout);
 leftLayout
   
     ->
   
     addWidget(caseCheckBox);
 leftLayout
   
     ->
   
     addWidget(backwardCheckBox);

 QVBoxLayout 
   
     *
   
     rightLayout 
   
     =
   
      
   
     new
   
      QVBoxLayout;
 rightLayout
   
     ->
   
     addWidget(findButton);
 rightLayout
   
     ->
   
     addWidget(closeButton);
 rightLayout
   
     ->
   
     addStretch(
   
     1
   
     );
   
     //

   
     
 QHBoxLayout 
   
     *
   
     mainLayout 
   
     =
   
      
   
     new
   
      QHBoxLayout(
   
     this
   
     );
 mainLayout
   
     ->
   
     setMargin(
   
     11
   
     );
 mainLayout
   
     ->
   
     setSpacing(
   
     4
   
     );
 mainLayout
   
     ->
   
     addLayout(leftLayout);
 mainLayout
   
     ->
   
     addLayout(rightLayout);
 setLayout(mainLayout);

 setWindowTitle(tr(
   
     "
   
     Find...
   
     "
   
     ));
}



   
     void
   
      FindDialog::findClicked()
{
 QString text 
   
     =
   
      lineEdit
   
     ->
   
     text();
 
   
     bool
   
      caseSensitive 
   
     =
   
      caseCheckBox
   
     ->
   
     isChecked();

 
   
     if
   
     (backwardCheckBox
   
     ->
   
     isChecked())
 emit findPrev(text,caseSensitive);
 
   
     else
   
     
 emit findNext(text,caseSensitive);
}


   
     void
   
      FindDialog::enableFindButton(
   
     const
   
      QString 
   
     &
   
     text)
{
 findButton
   
     ->
   
     setEnabled(
   
     !
   
     text.isEmpty());
}
  
    

main.cpp

  
    

   
     #include 
   
     <
   
     QApplication
   
     >
   
     
#include 
   
     <
   
     QPushButton
   
     >
   
     
#include 
   
     <
   
     QHBoxLayout
   
     >
   
     
#include 
   
     <
   
     QWidget
   
     >
   
     
#include 
   
     "
   
     finddialog.h
   
     "
   
     

   
     int
   
      main(
   
     int
   
      argc, 
   
     char
   
      
   
     *
   
     argv[])
{
 QApplication app(argc,argv);
 FindDialog 
   
     *
   
     dialog 
   
     =
   
      
   
     new
   
      FindDialog;
 dialog
   
     ->
   
     show();
 
   
     return
   
      app.exec();
}
  
    

效果图: