Qt-Qt之使用QEventLoop说明

相关资料：

 https://download.csdn.net/download/zhujianqiangqq/86727773      CSDN代码包下载

实例代码：

.pro

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++11

# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    mainwindow.cpp

HEADERS += \
    mainwindow.h

FORMS += \
    mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

main.cpp

#include "mainwindow.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTimer>
#include <QEventLoop>
#include <QDialog>
#include <windows.h>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_pushButton_clicked();

    void on_pushButton_2_clicked();

    void on_pushButton_3_clicked();

    void on_pushButton_4_clicked();

    void on_pushButton_5_clicked();

    void on_pushButton_6_clicked();

private:
    Ui::MainWindow *ui;
    QEventLoop loop;//定义一个事件循环
};
#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    setWindowTitle(QStringLiteral("Qt之使用QEventLoop说明"));
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_pushButton_clicked()
{
    loop.exec();
    ui->textEdit->append(QStringLiteral("loop exec OK!"));
}

void MainWindow::on_pushButton_2_clicked()
{
    loop.quit();
    ui->textEdit->append(QStringLiteral("loop quit OK!"));
}

void MainWindow::on_pushButton_3_clicked()
{
    ui->textEdit->append(QStringLiteral("Sleep 1 OK!"));
    Sleep(3000);
    ui->textEdit->append(QStringLiteral("Sleep 3000 OK!"));
}

void MainWindow::on_pushButton_4_clicked()
{
    ui->textEdit->append(QStringLiteral("QEventLoop 1 OK!"));
    QEventLoop eventloop;
    QTimer::singleShot(3000, &eventloop, SLOT(quit()));
    eventloop.exec();
    ui->textEdit->append(QStringLiteral("QEventLoop 3000 OK!"));
}

void MainWindow::on_pushButton_5_clicked()
{
    QDialog dlg;
    dlg.show();
    ui->textEdit->append(QStringLiteral("QDialog OK!"));
}

void MainWindow::on_pushButton_6_clicked()
{
    QDialog dlg;
    dlg.show();
    ui->textEdit->append(QStringLiteral("QDialog QEventLoop OK!"));
    QEventLoop loop;
    connect(&dlg, SIGNAL(finished(int)), &loop, SLOT(quit()));
    loop.exec(QEventLoop::ExcludeUserInputEvents);
}

mainwindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>699</width>
    <height>221</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <layout class="QVBoxLayout" name="verticalLayout_2">
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout" stretch="2,3">
      <item>
       <widget class="QTextEdit" name="textEdit"/>
      </item>
      <item>
       <layout class="QVBoxLayout" name="verticalLayout">
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_3">
          <item>
           <widget class="QPushButton" name="pushButton_5">
            <property name="text">
             <string>QDialog 直接弹</string>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QPushButton" name="pushButton_6">
            <property name="text">
             <string>QDialog QEventLoop</string>
            </property>
           </widget>
          </item>
         </layout>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_2">
          <item>
           <widget class="QPushButton" name="pushButton">
            <property name="text">
             <string>loop.exec()</string>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QPushButton" name="pushButton_2">
            <property name="text">
             <string>loop.quit()</string>
            </property>
           </widget>
          </item>
         </layout>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_4">
          <item>
           <widget class="QPushButton" name="pushButton_3">
            <property name="text">
             <string>Sleep(3000)</string>
            </property>
           </widget>
          </item>
          <item>
           <widget class="QPushButton" name="pushButton_4">
            <property name="text">
             <string>QEventLoop(3000)</string>
            </property>
           </widget>
          </item>
         </layout>
        </item>
       </layout>
      </item>
     </layout>
    </item>
   </layout>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

 

 

 

 

 

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