update

example/src/component/FileWatcher.cpp

@@ -0,0 +1,26 @@
+#include "FileWatcher.h"
+
+#include <qDebug>
+
+FileWatcher::FileWatcher(QObject *parent)
+    : QObject{parent}
+{
+    connect(&_watcher, &QFileSystemWatcher::fileChanged, this, [=](const QString &path){
+        Q_EMIT fileChanged();
+        clean();
+        _watcher.addPath(_path);
+    });
+    connect(this,&FileWatcher::pathChanged,this,[=](){
+        clean();
+        _watcher.addPath(_path.replace("file:///",""));
+    });
+    if(!_path.isEmpty()){
+        _watcher.addPath(_path);
+    }
+}
+
+void FileWatcher::clean(){
+    foreach (const QString &item,  _watcher.files()) {
+        _watcher.removePath(item);
+    }
+}

example/src/component/FileWatcher.h

@@ -0,0 +1,21 @@
+#ifndef FILEWATCHER_H
+#define FILEWATCHER_H
+
+#include <QObject>
+#include <QFileSystemWatcher>
+#include "src/stdafx.h"
+
+class FileWatcher : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY_AUTO(QString,path);
+public:
+    explicit FileWatcher(QObject *parent = nullptr);
+    Q_SIGNAL void fileChanged();
+private:
+    void clean();
+private:
+    QFileSystemWatcher _watcher;
+};
+
+#endif // FILEWATCHER_H