C++ QFileSystemWatcher在控制台应用程序中不发出fileChanged()
在我的文件控制台.h/.cpp中,我有一个小类,它只要求用户键入一些文本,然后再次打印文本,直到用户输入“退出”(请参见方法C++ QFileSystemWatcher在控制台应用程序中不发出fileChanged(),c++,qt,console,qfilesystemwatcher,C++,Qt,Console,Qfilesystemwatcher,在我的文件控制台.h/.cpp中,我有一个小类,它只要求用户键入一些文本,然后再次打印文本,直到用户输入“退出”(请参见方法consoleMain())。然而,在main.cpp中,我还有一个 QFileSystemWatcher它监视文件MyTextFile.txt,并在文本文件更改时调用控制台::slotFileChanged(QString)。不幸的是,QFileSystemWatcher无法工作控制台::slotFileChanged(QString)在我更改文本文件时从不执行。据我所知
consoleMain()
)。然而,在main.cpp中,我还有一个
QFileSystemWatcher
它监视文件MyTextFile.txt,并在文本文件更改时调用控制台::slotFileChanged(QString)
。不幸的是,QFileSystemWatcher
无法工作<代码>控制台::slotFileChanged(QString)在我更改文本文件时从不执行。据我所知,QFileSystemWatcher
仅在主事件循环已启动时工作,我的代码也是如此。
当我禁用main.cpp中的QTimer::singlaShot
并将其替换为emit console.signalStart()
主事件循环将不会被输入,但我在输入“退出”后会看到QFileSystemWatcher
(“文件已更改!”)的消息。
问题是:当文本文件并行更改时,是否可以让用户与控制台交互并让FileWatcher发出信号?
(我还尝试将QFileSystemWatcher
放入控制台类并在堆上创建它;不幸的是,它没有改变任何东西)
这是我的密码:
控制台.h
#ifndef CONSOLE_H
#define CONSOLE_H
#include <iostream>
#include <QObject>
#include <QFileSystemWatcher>
class Console: public QObject
{
Q_OBJECT
public:
Console(QObject *parent = 0);
~Console();
signals:
void signalStart();
void signalEnd();
public slots:
void consoleMain();
void slotFileChanged(QString text);
void slotEmit();
};
#endif // CONSOLE_H
#ifndef MYOBJECT_H
#define MYOBJECT_H
#include "console.h"
#include <QThread>
#include <QCoreApplication>
class MyObject : public QObject
{
Q_OBJECT
public:
MyObject(QObject *parent = 0);
~MyObject();
private:
QThread *thread;
Console *console;
signals:
void signalStart();
public slots:
void slotFileChanged(QString text);
void slotEnd();
};
#endif // MYOBJECT_H
\ifndef控制台\u H
#定义控制台
#包括
#包括
#包括
类控制台:公共QObject
{
Q_对象
公众:
控制台(QObject*parent=0);
~Console();
信号:
void signalStart();
void signalEnd();
公众时段:
void consoleMain();
void slotFileChanged(QString文本);
void slotEmit();
};
#endif//CONSOLE\u H
控制台.cpp
#include "console.h"
Console::Console(QObject *parent): QObject(parent)
{
}
Console::~Console()
{
}
void Console::consoleMain()
{
bool isRunning = true;
std::string in;
while (isRunning)
{
std::cout << ">" << std::flush;
std::getline(std::cin, in);
if (in.compare("quit") == 0)
isRunning = false;
else
std::cout << "You have entered: " << in << std::endl;
}
emit signalEnd();
}
void Console::slotFileChanged(QString text)
{
Q_UNUSED(text);
std::cout << "File changed!" << std::endl;
}
void Console::slotEmit()
{
emit signalStart();
}
#include "console.h"
#include <QCoreApplication>
#include <QTimer>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QFileSystemWatcher watcher(&a);
watcher.addPath("C:/MyTextFile.txt");
Console console(&a);
QObject::connect(&console, SIGNAL(signalStart()), &console, SLOT(consoleMain()));
QObject::connect(&console, SIGNAL(signalEnd()), &a, SLOT(quit()));
QObject::connect(&watcher, SIGNAL(fileChanged(QString)), &console, SLOT(slotFileChanged(QString)));
QTimer::singleShot(0, &console, SLOT(slotEmit()));
//emit console.signalStart();
std::cout << "Enter main event loop now" << std::endl;
return a.exec();
}
#include "myobject.h"
MyObject::MyObject(QObject *parent): QObject(parent)
{
console = new Console;
thread = new QThread(this);
console->moveToThread(thread);
thread->start();
connect(this, SIGNAL(signalStart()), console, SLOT(consoleMain()));
connect(console, SIGNAL(signalEnd()), this, SLOT(slotEnd()));
emit signalStart();
}
MyObject::~MyObject()
{
thread->quit();
thread->wait();
}
void MyObject::slotFileChanged(QString text)
{
console->displayChangedFileText(text);
}
void MyObject::slotEnd()
{
QCoreApplication::exit(0);
}
#include "myobject.h"
#include <QTimer>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QFileSystemWatcher *watcher = new QFileSystemWatcher(&a);
watcher->addPath("C:/MyTextFile.txt");
MyObject *object = new MyObject(&a);
QObject::connect(watcher, SIGNAL(fileChanged(QString)), object, SLOT(slotFileChanged(QString)));
std::cout << "Enter main event loop now" << std::endl;
return a.exec();
}
#包括“console.h”
控制台::控制台(QObject*父级):QObject(父级)
{
}
控制台::~Console()
{
}
void控制台::控制台main()
{
bool isRunning=true;
std::字符串输入;
同时(正在运行)
{
好的,问题解决了。我用不同的线程尝试了雅克的想法(感谢雅克的想法)。我必须引入一个名为MyObject
的QObject
的新子类。在其构造函数中,我为Console对象创建了Console
和一个新的QThread
。在main.cpp中创建了QFileSystemWatcher
。请参见下面的代码:
myobject.h
#ifndef CONSOLE_H
#define CONSOLE_H
#include <iostream>
#include <QObject>
#include <QFileSystemWatcher>
class Console: public QObject
{
Q_OBJECT
public:
Console(QObject *parent = 0);
~Console();
signals:
void signalStart();
void signalEnd();
public slots:
void consoleMain();
void slotFileChanged(QString text);
void slotEmit();
};
#endif // CONSOLE_H
#ifndef MYOBJECT_H
#define MYOBJECT_H
#include "console.h"
#include <QThread>
#include <QCoreApplication>
class MyObject : public QObject
{
Q_OBJECT
public:
MyObject(QObject *parent = 0);
~MyObject();
private:
QThread *thread;
Console *console;
signals:
void signalStart();
public slots:
void slotFileChanged(QString text);
void slotEnd();
};
#endif // MYOBJECT_H
main.cpp
#include "console.h"
Console::Console(QObject *parent): QObject(parent)
{
}
Console::~Console()
{
}
void Console::consoleMain()
{
bool isRunning = true;
std::string in;
while (isRunning)
{
std::cout << ">" << std::flush;
std::getline(std::cin, in);
if (in.compare("quit") == 0)
isRunning = false;
else
std::cout << "You have entered: " << in << std::endl;
}
emit signalEnd();
}
void Console::slotFileChanged(QString text)
{
Q_UNUSED(text);
std::cout << "File changed!" << std::endl;
}
void Console::slotEmit()
{
emit signalStart();
}
#include "console.h"
#include <QCoreApplication>
#include <QTimer>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QFileSystemWatcher watcher(&a);
watcher.addPath("C:/MyTextFile.txt");
Console console(&a);
QObject::connect(&console, SIGNAL(signalStart()), &console, SLOT(consoleMain()));
QObject::connect(&console, SIGNAL(signalEnd()), &a, SLOT(quit()));
QObject::connect(&watcher, SIGNAL(fileChanged(QString)), &console, SLOT(slotFileChanged(QString)));
QTimer::singleShot(0, &console, SLOT(slotEmit()));
//emit console.signalStart();
std::cout << "Enter main event loop now" << std::endl;
return a.exec();
}
#include "myobject.h"
MyObject::MyObject(QObject *parent): QObject(parent)
{
console = new Console;
thread = new QThread(this);
console->moveToThread(thread);
thread->start();
connect(this, SIGNAL(signalStart()), console, SLOT(consoleMain()));
connect(console, SIGNAL(signalEnd()), this, SLOT(slotEnd()));
emit signalStart();
}
MyObject::~MyObject()
{
thread->quit();
thread->wait();
}
void MyObject::slotFileChanged(QString text)
{
console->displayChangedFileText(text);
}
void MyObject::slotEnd()
{
QCoreApplication::exit(0);
}
#include "myobject.h"
#include <QTimer>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QFileSystemWatcher *watcher = new QFileSystemWatcher(&a);
watcher->addPath("C:/MyTextFile.txt");
MyObject *object = new MyObject(&a);
QObject::connect(watcher, SIGNAL(fileChanged(QString)), object, SLOT(slotFileChanged(QString)));
std::cout << "Enter main event loop now" << std::endl;
return a.exec();
}
#包括“myobject.h”
#包括
int main(int argc,char*argv[])
{
qcorea应用程序(argc、argv);
QFileSystemWatcher*watcher=新的QFileSystemWatcher(&a);
watcher->addPath(“C:/MyTextFile.txt”);
MyObject*object=新的MyObject(&a);
QObject::connect(监视程序、信号(fileChanged(QString))、对象、插槽(slotFileChanged(QString));
std::你能显式地调用控制台main
吗?直到它完成运行,它才会运行。据我所知,Qt几乎没有控制台支持。解决这个问题的最简单方法可能是让控制台上有一个线程,主事件循环在另一个线程上运行,并让控制台发送消息与ma通信在事件循环中,谷歌找到的答案似乎传递了通过消息键入的字符,而这些字符必须手动重新组合。