界面关闭的事件响应
最近使用了窗口关闭事件：void QWidget::closeEvent ( QCloseEvent * event ) [virtual protected]
当用鼠标点击关闭按钮或者在任务栏上右击关闭，都会触发这一事件，实现效果如下：
附上实现代码：
这是主界面的关闭事件（CallTrace为主界面）
1 void CallTrace::closeEvent(QCloseEvent *e) 2 { 3 closeDialog = new CloseDialog; 4 closeDialog->move((QApplication::desktop()->width() - closeDialog->width())/2, 5 (QApplication::desktop()->height() - closeDialog->height())/2); 6 closeDialog->exec(); 7 if (closeDialog->m_flag)//先判断没有出错 8 { 9 if (closeDialog->m_flag == 3)//窗口不关闭 10 { 11 e->ignore(); 12 } 13 else if (closeDialog->m_flag == 2)//立即关闭 14 { 15 //关闭线程 16 pTaskInstance->m_CDR.StopCdr(); 17 emit mysig(); //发射信号，记录窗口及线程状态 18 } 19 else if (closeDialog->m_flag == 1)//隐藏到后台 20 { 21 //什么都不用做 22 } 23 } 24 }
1 CloseDialog::CloseDialog() 2 { 3 m_flag = 0;//窗口关闭选项的初始化 4 QGroupBox *closeSelection = new QGroupBox(tr("关闭选项")); 5 hide = new QRadioButton(tr("隐藏到后台")); 6 hide->setChecked(true); 7 holdOn = new QRadioButton(tr("立即关闭")); 8 9 QVBoxLayout *vLayout1 = new QVBoxLayout; 10 vLayout1->addWidget(hide); 11 vLayout1->addWidget(holdOn); 12 closeSelection->setLayout(vLayout1); 13 14 QHBoxLayout *hLayout1 = new QHBoxLayout; 15 okBtn = new QPushButton(tr("确定")); 16 cancelBtn = new QPushButton(tr("取消")); 17 hLayout1->addStretch(); 18 hLayout1->addWidget(okBtn); 19 hLayout1->addSpacing(10); 20 hLayout1->addWidget(cancelBtn); 21 hLayout1->addStretch(); 22 23 QHBoxLayout *hLayout2 = new QHBoxLayout; 24 closeCbox = new QCheckBox; 25 closeCbox->setText(tr("默认此选项，以后不再提示")); 26 hLayout2->addWidget(closeCbox); 27 28 QVBoxLayout *mainLayout = new QVBoxLayout; 29 mainLayout->addWidget(closeSelection); 30 mainLayout->addLayout(hLayout2); 31 mainLayout->addLayout(hLayout1); 32 33 setLayout(mainLayout); 34 setWindowTitle(tr("提示")); 35 this->resize(400,200); 36 37 connect(okBtn,SIGNAL(clicked()),this,SLOT(ok_PushButton_Clicked())); 38 connect(cancelBtn,SIGNAL(clicked()),this,SLOT(cancel_PushButton_Clicked())); 39 }
1 //弹出小窗口关闭 2 void CloseDialog::closeEvent(QCloseEvent *e) 3 { 4 if (!m_flag)//若直接关闭对话框，m_flag置3 5 { 6 m_flag = 3;//保持原状态，不关闭 7 } 8 }
//确定按钮
1 void CloseDialog::ok_PushButton_Clicked() 2 { 3 if (hide->isChecked()) 4 { 5 m_flag = 1;//隐藏到后台 6 } 7 else if (holdOn->isChecked()) 8 { 9 m_flag = 2;//立即关闭 10 } 11 this->close(); 12 } 13 14 //取消按钮 15 void CloseDialog::cancel_PushButton_Clicked() 16 { 17 m_flag = 3;//保持原状态，不关闭 18 this->close(); 19 }
//.h文件
1 class CloseDialog : public QDialog 2 { 3 Q_OBJECT 4 public: 5 CloseDialog(); 6 ~CloseDialog(); 7 8 public: 9 QRadioButton *hide; 10 QRadioButton *holdOn; 11 QPushButton *okBtn; 12 QPushButton *cancelBtn; 13 QCheckBox *closeCbox; 14 int m_flag; //标志，记录隐藏窗口还是关闭 1隐藏到后台，2立即关闭，3不改变，0错误 15 16 protected: 17 void closeEvent(QCloseEvent *e);//窗口关闭时调用 18 public slots: 19 void ok_PushButton_Clicked(); 20 void cancel_PushButton_Clicked(); 21 };
主要就是 closeEvent(QCloseEvent *e)和ignore()函数的使用
另外，当用户关闭一个主窗口时，默认行为是隐藏它，所以它还会保留在内存中。
当我们确定需要调用窗口类的析构时，需要在构造函数中对 Qt::WA_DeleteOnClose的属性进行设置
1 MainWindow::MainWindow() 2 { 3 ... 4 setAttribute(Qt::WA_DeleteOnClose); 5 ... 6 }
这样做就会告诉Qt在关闭窗口时将其删除
