在早期开发的软件中，尤其是初学者入门者写的软件，软件运行久了，难免遇到意外崩溃的时候，可是大部分的运行设备可能在现场客户那，需要记住每一次从软件启动后到软件意外关闭前的运行时间，需要记录的信息包括：编号+开始时间+结束时间+已运行时间，每次完整的运行过程只产生一条记录，每次运行时间改变以后更新当前这条记录即可。这样就可以确切的了解到软件在现场的真实运行情况是否糟糕，如果没有这个记录（当然可以选择记录存储到数据库），程序又重启恢复了，也不知道到底每次运行了多久，从几点到几点。

为了写的简单点，不干扰原有的数据库文件，我一般选择输出到文本文件。

完整代码下载： 

完整代码：

#ifndef SAVERUNTIME_H#define SAVERUNTIME_H#include 
     
      #include 
      
       class QTimer;#ifdef quc#if (QT_VERSION < QT_VERSION_CHECK(5,7,0))#include 
       
        #else#include 
        
         #endifclass QDESIGNER_WIDGET_EXPORT SaveRunTime : public QObject#elseclass SaveRunTime : public QObject#endif{    Q_OBJECTpublic:    static SaveRunTime *Instance();    explicit SaveRunTime(QObject *parent = 0);private:    static QScopedPointer
         
           self;    QString path;       //日志文件路径    QString name;       //日志文件名称    int lastID;    int saveInterval;    QDateTime startTime;    QString logFile;    QTimer *timerSave;private:    void getDiffValue(const QDateTime &startTime, const QDateTime &endTime, int &day, int &hour, int &minute);signals:public slots:    void start();       //启动服务    void stop();        //停止服务    void initLog();     //初始化日志文件    void appendLog();   //追加一条记录到日志文件    void saveLog();     //保存运行时间到日志文件    void setPath(const QString &path);    void setName(const QString &name);    void setSaveInterval(int saveInterval);};#endif // SAVERUNTIME_H#include "saveruntime.h"#include "qmutex.h"#include "qapplication.h"#include "qtimer.h"#include "qfile.h"#include "qtextstream.h"#include "qstringlist.h"#include "qdebug.h"#ifdef Q_OS_WIN#define NEWLINE "\r\n"#else#define NEWLINE "\n"#endifQScopedPointer
          
            SaveRunTime::self;SaveRunTime *SaveRunTime::Instance(){ if (self.isNull()) { QMutex mutex; QMutexLocker locker(&mutex); if (self.isNull()) { self.reset(new SaveRunTime); } } return self.data();}SaveRunTime::SaveRunTime(QObject *parent) : QObject(parent){ path = qApp->applicationDirPath(); QString str = qApp->applicationFilePath(); QStringList list = str.split("/"); name = list.at(list.count() - 1).split(".").at(0); saveInterval = 1 * 60 * 1000; startTime = QDateTime::currentDateTime(); timerSave = new QTimer(this); timerSave->setInterval(saveInterval); connect(timerSave, SIGNAL(timeout()), this, SLOT(saveLog()));}void SaveRunTime::start(){ timerSave->start(); initLog(); appendLog(); saveLog();}void SaveRunTime::stop(){ timerSave->stop();}void SaveRunTime::getDiffValue(const QDateTime &startTime, const QDateTime &endTime, int &day, int &hour, int &minute){ qint64 sec = startTime.secsTo(endTime); day = hour = minute = 0; int seconds = 0; while (sec > 0) { seconds++; if (seconds == 60) { minute++; seconds = 0; } if (minute == 60) { hour++; minute = 0; } if (hour == 24) { day++; hour = 0; } sec--; }}void SaveRunTime::initLog(){ //判断当前年份的记事本文件是否存在,不存在则新建并且写入标题 //存在则自动读取最后一行的id号 记事本文件格式内容 //编号 开始时间 结束时间 已运行时间 //1 2016-01-01 12:33:33 2016-02-05 12:12:12 day: 0 hour: 0 minute: 0 logFile = QString("%1/%2_runtime_%3.txt").arg(path).arg(name).arg(QDate::currentDate().year()); QFile file(logFile); if (file.size() == 0) { if (file.open(QFile::WriteOnly | QFile::Text)) { QString strID = QString("%1\t").arg("编号"); QString strStartTime = QString("%1\t\t").arg("开始时间"); QString strEndTime = QString("%1\t\t").arg("结束时间"); QString strRunTime = QString("%1").arg("已运行时间"); QString line = strID + strStartTime + strEndTime + strRunTime; QTextStream stream(&file); stream << line << NEWLINE; file.close(); lastID = 0; } } else { if (file.open(QFile::ReadOnly)) { QString lastLine; while (!file.atEnd()) { lastLine = file.readLine(); } file.close(); QStringList list = lastLine.split("\t"); lastID = list.at(0).toInt(); } } lastID++;}void SaveRunTime::appendLog(){ logFile = QString("%1/%2_runtime_%3.txt").arg(path).arg(name).arg(QDate::currentDate().year()); QFile file(logFile); //写入当前首次运行时间 if (file.open(QFile::WriteOnly | QFile::Append | QFile::Text)) { QString strID = QString("%1\t").arg(lastID); QString strStartTime = QString("%1\t").arg(startTime.toString("yyyy-MM-dd HH:mm:ss")); QString strEndTime = QString("%1\t").arg(QDateTime::currentDateTime().toString("yyyy-MM-dd HH:mm:ss")); int day, hour, minute; getDiffValue(startTime, QDateTime::currentDateTime(), day, hour, minute); QString strRunTime = QString("%1 天 %2 时 %3 分").arg(day).arg(hour).arg(minute); QString line = strID + strStartTime + strEndTime + strRunTime; QTextStream stream(&file); stream << line << NEWLINE; file.close(); }}void SaveRunTime::saveLog(){ //每次保存都是将之前的所有文本读取出来,然后替换最后一行即可 logFile = QString("%1/%2_runtime_%3.txt").arg(path).arg(name).arg(QDate::currentDate().year()); QFile file(logFile); //如果日志文件不存在,则初始化一个日志文件 if (file.size() == 0) { initLog(); appendLog(); return; } if (file.open(QFile::ReadWrite)) { //一行行读取到链表 QStringList content; while (!file.atEnd()) { content.append(file.readLine()); } //重新清空文件 file.resize(0); //如果行数小于2则返回 if (content.count() < 2) { file.close(); return; } QString lastLine = content.last(); QStringList list = lastLine.split("\t"); //计算已运行时间 int day, hour, minute; getDiffValue(startTime, QDateTime::currentDateTime(), day, hour, minute); QString strRunTime = QString("%1 天 %2 时 %3 分").arg(day).arg(hour).arg(minute); //重新拼接最后一行 list[2] = QDateTime::currentDateTime().toString("yyyy-MM-dd HH:mm:ss"); list[3] = strRunTime; lastLine = list.join("\t"); //重新替换最后一行并写入新的数据 content[content.count() - 1] = lastLine; QTextStream stream(&file); stream << content.join("") << NEWLINE; file.close(); }}void SaveRunTime::setPath(const QString &path){ if (this->path != path) { this->path = path; }}void SaveRunTime::setName(const QString &name){ if (this->name != name) { this->name = name; }}void SaveRunTime::setSaveInterval(int saveInterval){ if (this->saveInterval != saveInterval) { this->saveInterval = saveInterval; timerSave->setInterval(saveInterval); }}