Qt制作定时关机小程序

引言

一般定时关机采用命令行模式，还需要我们计算在多久后关机，我们可以做一个小程序来定时关机

完成效果图

ui界面

<?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>330</width>
    <height>240</height>
   </rect>
  </property>
  <property name="minimumSize">
   <size>
    <width>330</width>
    <height>240</height>
   </size>
  </property>
  <property name="maximumSize">
   <size>
    <width>330</width>
    <height>240</height>
   </size>
  </property>
  <property name="font">
   <font>
    <pointsize>10</pointsize>
   </font>
  </property>
  <widget class="QWidget" name="centralwidget">
   <layout class="QGridLayout" name="gridLayout_2">
    <item row="3" column="1">
     <widget class="QWidget" name="widget" native="true">
      <layout class="QGridLayout" name="gridLayout">
       <item row="2" column="0">
        <layout class="QHBoxLayout" name="horizontalLayout_2">
         <item>
          <widget class="QPushButton" name="shutdownButton">
           <property name="text">
            <string>关机</string>
           </property>
          </widget>
         </item>
         <item>
          <widget class="QPushButton" name="cancelShutdownButton">
           <property name="text">
            <string>取消</string>
           </property>
          </widget>
         </item>
        </layout>
       </item>
       <item row="0" column="0">
        <layout class="QHBoxLayout" name="horizontalLayout">
         <item>
          <widget class="QComboBox" name="hourComboBox">
           <property name="minimumSize">
            <size>
             <width>62</width>
             <height>22</height>
            </size>
           </property>
           <property name="maximumSize">
            <size>
             <width>62</width>
             <height>22</height>
            </size>
           </property>
           <property name="editable">
            <bool>false</bool>
           </property>
          </widget>
         </item>
         <item>
          <widget class="QLabel" name="hourLabel">
           <property name="minimumSize">
            <size>
             <width>0</width>
             <height>0</height>
            </size>
           </property>
           <property name="text">
            <string>时</string>
           </property>
          </widget>
         </item>
         <item>
          <spacer name="horizontalSpacer_3">
           <property name="orientation">
            <enum>Qt::Horizontal</enum>
           </property>
           <property name="sizeHint" stdset="0">
            <size>
             <width>40</width>
             <height>20</height>
            </size>
           </property>
          </spacer>
         </item>
         <item>
          <widget class="QComboBox" name="minuteComboBox">
           <property name="minimumSize">
            <size>
             <width>62</width>
             <height>22</height>
            </size>
           </property>
           <property name="maximumSize">
            <size>
             <width>62</width>
             <height>22</height>
            </size>
           </property>
           <property name="editable">
            <bool>false</bool>
           </property>
          </widget>
         </item>
         <item>
          <widget class="QLabel" name="minuteLabel">
           <property name="text">
            <string>分</string>
           </property>
          </widget>
         </item>
        </layout>
       </item>
       <item row="1" column="0">
        <spacer name="verticalSpacer_4">
         <property name="orientation">
          <enum>Qt::Vertical</enum>
         </property>
         <property name="sizeHint" stdset="0">
          <size>
           <width>20</width>
           <height>30</height>
          </size>
         </property>
        </spacer>
       </item>
      </layout>
     </widget>
    </item>
    <item row="3" column="0">
     <spacer name="horizontalSpacer">
      <property name="orientation">
       <enum>Qt::Horizontal</enum>
      </property>
      <property name="sizeHint" stdset="0">
       <size>
        <width>40</width>
        <height>20</height>
       </size>
      </property>
     </spacer>
    </item>
    <item row="0" column="1">
     <spacer name="verticalSpacer_2">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
      </property>
      <property name="sizeHint" stdset="0">
       <size>
        <width>20</width>
        <height>40</height>
       </size>
      </property>
     </spacer>
    </item>
    <item row="4" column="1">
     <spacer name="verticalSpacer">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
      </property>
      <property name="sizeHint" stdset="0">
       <size>
        <width>20</width>
        <height>40</height>
       </size>
      </property>
     </spacer>
    </item>
    <item row="3" column="2">
     <spacer name="horizontalSpacer_2">
      <property name="orientation">
       <enum>Qt::Horizontal</enum>
      </property>
      <property name="sizeHint" stdset="0">
       <size>
        <width>40</width>
        <height>20</height>
       </size>
      </property>
     </spacer>
    </item>
    <item row="1" column="1">
     <widget class="QLabel" name="label">
      <property name="minimumSize">
       <size>
        <width>186</width>
        <height>30</height>
       </size>
      </property>
      <property name="maximumSize">
       <size>
        <width>186</width>
        <height>30</height>
       </size>
      </property>
      <property name="text">
       <string>                   设置关机时间</string>
      </property>
     </widget>
    </item>
    <item row="2" column="1">
     <spacer name="verticalSpacer_3">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
      </property>
      <property name="sizeHint" stdset="0">
       <size>
        <width>20</width>
        <height>30</height>
       </size>
      </property>
     </spacer>
    </item>
   </layout>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

ui样图

main函数

#include "mainwindow.h"

#include <QApplication>

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

窗口文件

核心逻辑
采用信号和槽，完成事件链接

 QProcess::startDetached("shutdown", QStringList() << "/s" << "/t" << QString::number(timeSeconds));

 QProcess::execute("shutdown", QStringList() << "/a");

头文件

// mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTimer>
#include <QDateTime>
#include <QProcess>
#include <QMessageBox>
#include <QString>
#include <QDebug>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
private slots:
    void onShutdownButtonClicked();
    void onCancelShutdownButtonClicked();

private:
    Ui::MainWindow *ui;
    QTimer *shutdownTimer;

};

#endif // MAINWINDOW_H

cpp文件

// mainwindow.cpp

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

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

    // 获取当前时间
    QTime currentTime = QTime::currentTime();


    // 设置小时下拉框
    ui->hourComboBox->setEditable(false);
    for (int i = 0; i < 24; ++i) {
        // 比较当前时间与选项时间
    if (currentTime.hour() <= i) {
            ui->hourComboBox->addItem(QString::number(i));
        }
    }
        // 选择当前小时作为已选中项
    ui->hourComboBox->setCurrentIndex(ui->hourComboBox->findText(QString::number(currentTime.hour())));

        // 设置分钟下拉框
    ui->minuteComboBox->setEditable(false);
    for (int i = 0; i < 60; ++i) {
        // 比较当前时间与选项时间
    if (currentTime.minute() <= i) {
            ui->minuteComboBox->addItem(QString::number(i));
        }
    }
        // 选择当前分钟作为已选中项
    ui->minuteComboBox->setCurrentIndex(ui->minuteComboBox->findText(QString::number(currentTime.minute())));

    // 连接按钮点击事件到槽函数
    connect(ui->shutdownButton, &QPushButton::clicked, this, &MainWindow::onShutdownButtonClicked);
    connect(ui->cancelShutdownButton, &QPushButton::clicked, this, &MainWindow::onCancelShutdownButtonClicked);
}

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

void MainWindow::onShutdownButtonClicked()
{
    // 获取用户选择的小时和分钟
    int selectedHour = ui->hourComboBox->currentText().toInt();
    int selectedMinute = ui->minuteComboBox->currentText().toInt();

    // 获取当前时间
    QDateTime currentTime = QDateTime::currentDateTime();

    // 获取用户选择的时间
    QDateTime shutdownTime = QDateTime(currentTime.date(), QTime(selectedHour, selectedMinute));

    // 计算时间差
    qint64 timeDifference = currentTime.msecsTo(shutdownTime);

    int timeSeconds=int(timeDifference/1000);
    // 设置定时器的超时时间
    //shutdownTimer->start(timeDifference);

    QProcess::startDetached("shutdown", QStringList() << "/s" << "/t" << QString::number(timeSeconds));
    // 提示用户关机已设置
    QMessageBox::information(this, "关机设置", "关机已设置，将在选择的时间执行！");
}

void MainWindow::onCancelShutdownButtonClicked()
{
    // 取消关机
    QProcess::execute("shutdown", QStringList() << "/a");
    QMessageBox::information(this, "取消关机", "已取消关机操作！");
}