【QML】QML复制文件或文件夹，显示进度，多线程复制

1. 效果

可以显示复制文件和文件夹的进度
复制文件： bool copyFileFunc(QString _from, QString _to);
复制文件夹：bool copyDirectoryFiles(const QString &_from, const QString &_to);
举例：

	//复制文件copyhelper.copyFileToDir("./test.txt", "d:/copytest/dir/test1.txt");//复制文件夹copyhelper.copyFileToDir("./copyTest", "d:/copytest/dir/copyTest1");

2. QML代码

import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.15
import QtQuick.Controls.Styles 1.4
import QtQuick.Controls 1.4Window {width: 640height: 480visible: truetitle: qsTr("copy file")Rectangle{id: _progresswidth: parent.widthheight: parent.height / 2border.color: "blue"border.width: 1property string processv: "0"ProgressBar {id: pbarwidth: 480;height: 30minimumValue:  0maximumValue:  100value: 0anchors.centerIn: parentstyle: ProgressBarStyle{id: progressStylebackground: Rectangle{color: "lightgrey"radius: 6}progress: Rectangle{color: control.value === 100 ? "#b1d946" :"#4c7aff"radius: 6}panel: Item{//通过panel属性，可以加载  progress Text background等组件//设置外边框implicitWidth: 480;implicitHeight: 15;Loader{anchors.fill:  parent;sourceComponent: background;}Loader{id: progressLoader;anchors.top: parent.top;anchors.left: parent.left;anchors.bottom:  parent.bottom;anchors.margins: 0;z: 1;width: currentProgress * (parent.width);sourceComponent: progressStyle.progress;}Text{color: "black"text: _progress.processvz: 2anchors.centerIn: parent}}}}}Button{width: 200height: 100anchors.top: _progress.bottomanchors.horizontalCenter: _progress.horizontalCenteranchors.topMargin: 20text: qsTr("开始复制")onClicked: {console.log("开始复制")//复制文件//copyhelper.copyFileToDir("./test.txt", "d:/copytest/dir/test1.txt");//复制文件夹copyhelper.copyFileToDir("./copyTest", "d:/copytest/dir/copyTest1");}}Connections{target: copyhelperfunction onQmlCopyProgress(value){pbar.value = value;_progress.processv =  value + "%";}}
}

3. main.c代码

#include <QGuiApplication>
#include <QtQml>
#include <QApplication>
#include <QQmlApplicationEngine>
#include "copyhelper.h"int main(int argc, char *argv[])
{
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endifQApplication app(argc, argv);QQmlApplicationEngine engine;engine.rootContext()->setContextProperty("copyhelper", new CopyHelper);const QUrl url(QStringLiteral("qrc:/main.qml"));QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,&app, [url](QObject *obj, const QUrl &objUrl) {if (!obj && url == objUrl)QCoreApplication::exit(-1);}, Qt::QueuedConnection);engine.load(url);return app.exec();
}

4. .pro代码

QT += quick qml widgets core# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0SOURCES += \copyfiles.cpp \copyhelper.cpp \main.cppRESOURCES += qml.qrc# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH =# Additional import path used to resolve QML modules just for Qt Quick Designer
QML_DESIGNER_IMPORT_PATH =# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += targetHEADERS += \copyfiles.h \copyhelper.h

5. C++代码

创建两个类 CopyHelper 和 CopyFiles
CopyFiles中是具体实现
CopyHelper 为了实现多线程

5.1 copyfile.h

#ifndef COPYFILES_H
#define COPYFILES_H#include <QObject>
#include <QDebug>
#include <QFile>        //文件操作
#include <QDataStream>  //数据流
#include <QThread>      //线程class CopyFiles : public QObject
{Q_OBJECT
public://只能显式构造/***  QString _srcFilePath    : 源文件路径*  QString _dstPath        : 目标路径*  QObject *parent = 0     : 父对象指针，默认为空*/explicit CopyFiles(QString _srcFilePath, QString _dstPath,QObject *parent = 0);signals:void startCopyFile(QString, QString);   //复制文件信号void startCopyDir(QString, QString);    //复制文件夹信号void copyProcess(QString);              //复制文件进度信号public slots:/*** @brief copyFileFunction : 复制文件信号处理槽* @param _from : 源文件名* @param _to   : 目标文件名* @return bool : 返回类型 成功返回true 失败返回false*/bool copyFileFunc(QString _from, QString _to);/*** @brief copyDirectoryFiles : 复制文件夹* @param _from : 源文件夹路径* @param _to   : 目标文件夹路径* @return  : 成功返回true 失败返回false*/bool copyDirectoryFiles(const QString &_from, const QString &_to);private:bool m_firstRead = true;qint64 m_total = 0;qint64 m_now = 0;private:void getDirSize(QString _dir, qint64* size);bool copyFile(QString _from, QString _to, qint64* nowSize, qint64 totalSize);
};#endif // COPYFILES_H

5.2 copyfile.cpp

#include "copyfiles.h"
#include "qfileinfo.h"
#include <QFile>
#include <QDir>CopyFiles::CopyFiles(QString _srcFilePath, QString _dstPath, QObject *parent)
{qDebug() << QThread::currentThreadId() << _srcFilePath << _dstPath;
}bool CopyFiles::copyFileFunc(QString _from, QString _to)
{qint64 fileSize = 0;qint64 totalCopySize = 0;//文件夹创建QFileInfo fininfo(_to);QDir path;if(!path.exists(fininfo.absolutePath())){path.mkdir(fininfo.absolutePath());}//文件对象QFile tofile;tofile.setFileName(_to);QFile fromfile;fromfile.setFileName(_from);fileSize = fromfile.size();/* 复制文件 */return copyFile(_from, _to, &totalCopySize, fileSize);
}bool CopyFiles::copyDirectoryFiles(const QString &_from, const QString &_to)
{QDir sourceDir(_from);QDir targetDir(_to);qDebug() << "copy form" <<_from << _to;/* 如果目录不存在，则创建 */if(!targetDir.exists()){if(!targetDir.mkdir(targetDir.absolutePath())){return false;}}QFileInfoList fileInfoList = sourceDir.entryInfoList();if(m_firstRead){qDebug() << "copyDirectoryFiles count:" << fileInfoList.count();/* 获取文件夹总大小 */m_total = 0;getDirSize(_from, &m_total);/* 标志位 */m_now = 0;m_firstRead = false;qDebug() << "copyDirectoryFiles: " << m_total << m_now;/* 复制完成 */if(m_now == m_total){m_firstRead = true;}}foreach(QFileInfo fileInfo, fileInfoList){if(fileInfo.fileName() == "." || fileInfo.fileName() == ".."){continue;}/* 当前为目录递归进行copy */if(fileInfo.isDir()){if(!copyDirectoryFiles(fileInfo.filePath(), targetDir.filePath(fileInfo.fileName()))){return false;}}/* 复制文件 */else{if(!copyFile(fileInfo.filePath(), targetDir.filePath(fileInfo.fileName()), &m_now, m_total)){return false;}}}return true;
}void CopyFiles::getDirSize(QString _dir, qint64* size)
{QDir sourceDir(_dir);QFileInfoList fileInfoList = sourceDir.entryInfoList();/* 遍历文件夹 */foreach(QFileInfo fileInfo, fileInfoList){if(fileInfo.isFile()){if(fileInfo.fileName() != "." && fileInfo.fileName() != ".."){*size += fileInfo.size();qDebug() << "1-----" << fileInfo.fileName() << *size;}}else if(fileInfo.isDir()){/* 递归 */if(fileInfo.fileName() != "." && fileInfo.fileName() != ".."){getDirSize(fileInfo.filePath(), size);qDebug() << "2-----" << fileInfo.fileName() <<fileInfo.filePath();}}}
}bool CopyFiles::copyFile(QString _from, QString _to, qint64* nowSize, qint64 totalSize)
{qDebug() << "子线程ID:" << QThread::currentThreadId();char * byteTemp = new char[1024*8]; //每次复制8kqint64 fileSize = 0;qint64 totalCopySize = 0;//文件夹创建QFileInfo fininfo(_to);QDir path;if(!path.exists(fininfo.absolutePath())){path.mkdir(fininfo.absolutePath());}//文件对象QFile tofile;tofile.setFileName(_to);QFile fromfile;fromfile.setFileName(_from);//文件读取判断if(!tofile.open(QIODevice::WriteOnly)){qDebug() << "无法打开目标文件1";delete[](byteTemp);return false;}if(!fromfile.open(QIODevice::ReadOnly)){qDebug() << "无法打开目标文件2";delete[](byteTemp);return false;}//文件大小QDataStream out(&tofile);//文件流out.setVersion(QDataStream::Qt_4_0);fileSize = fromfile.size();QDataStream in(&fromfile);in.setVersion(QDataStream::Qt_4_0);qDebug() << "文件总大小:" << fileSize << " / " << QString::number(totalSize);//循环复制文件while(!in.atEnd()){qint64 readSize = 0;//每次读取8kreadSize = in.readRawData(byteTemp, 1024*8);    //读取复制文件到缓存并返回读取的实际大小out.writeRawData(byteTemp, readSize);           //写到输出流totalCopySize += readSize;                      //累计已复制大小*nowSize += readSize;int tmpVal = *nowSize / (double)totalSize * 100;//复制进度计算emit copyProcess(QString::number(tmpVal));      //发射当前复制进度//qDebug() << "now:" << *nowSize;}//复制完成if(totalCopySize == fileSize){tofile.setPermissions(QFile::ExeUser);//设置文件权限tofile.close();     //关闭文件流fromfile.close();   //关闭文件流delete[](byteTemp);return true;        //返回复制结果-成功}else{delete[](byteTemp);return false;       //返回复制结果-失败}
}

5.3 copyhelper.h

#ifndef COPYHELPER_H
#define COPYHELPER_H#include <QObject>class CopyHelper : public QObject
{Q_OBJECT
public:explicit CopyHelper(QObject *parent = 0);public:/*** @brief copyFileToDir 复制文件到目录* @return QString 返回字符串*/Q_INVOKABLE QString copyFileToDir(QString _from, QString _to);signals:/*** @brief qmlCopyProgress 供qml使用的复制文件进度信号* @param value*/void  qmlCopyProgress(QString value);private :/*** @brief testReadFile 测试读取文件*/void testReadFile();private slots:/*** @brief reciveCopyProgress 接收文件进度槽*/void reciveCopyProgress(QString);
};#endif // COPYHELPER_H

5.4 copyhelper.cpp

#include "copyhelper.h"
#include <QDebug>
#include <QFile>
#include <QDataStream>
#include <QThread>
#include <QFileInfo>
#include "copyfiles.h"CopyHelper::CopyHelper(QObject *parent) : QObject(parent)
{qDebug() << "文件复制助手线程ID:" <<QThread::currentThreadId();
}//复制文件到目录
QString CopyHelper::copyFileToDir(QString _from, QString _to)
{//构造复制文件类CopyFiles * m_pCopyFile = new CopyFiles(_from, _to);//复制文件子线程QThread * m_pCopyFilethread =  new QThread();m_pCopyFile->moveToThread(m_pCopyFilethread); //子线程中执行文件复制//连接文件复制信号connect(m_pCopyFile,SIGNAL(startCopyFile(QString,QString)),m_pCopyFile,SLOT(copyFileFunc(QString,QString)));connect(m_pCopyFile,SIGNAL(startCopyDir(QString,QString)),m_pCopyFile,SLOT(copyDirectoryFiles(QString,QString)));connect(m_pCopyFile,SIGNAL(copyProcess(QString)),this,SLOT(reciveCopyProgress(QString)));//链接线程完成信号connect(m_pCopyFilethread, SIGNAL(finished()), m_pCopyFilethread, SLOT(deleteLater()));connect(m_pCopyFilethread, &QThread::finished, m_pCopyFilethread, &QObject::deleteLater);//启动复制线程m_pCopyFilethread->start();//判断文件还是文件夹QFileInfo fileInfo(_from);if(fileInfo.isDir()){//发射文件夹复制开始信号emit m_pCopyFile->startCopyDir(_from, _to);}else{//发射文件复制开始信号emit m_pCopyFile->startCopyFile(_from, _to);}return "复制成功";
}//测试读取文件
void CopyHelper::testReadFile()
{//测试复制文件QString strFileName = "d:/test.rar";if (!QFile::exists(strFileName)){return;} //文件不存在QFile file(strFileName);if (!file.open(QFile::ReadOnly)){return;}//文件无法打开QDataStream in(&file);      //数据流int nFileSize = file.size();//文件大小int p = 0;                  //当前复制位置while (!in.atEnd()) {char buffer [8192];int readsize = 0;readsize = in.readRawData(buffer,8192);p = file.pos();qDebug() <<"文件总大小:"<<nFileSize<<"读取大小"<<readsize<<" 当前复制进度"<<QString::number(p);}
}//接收文件进度
void CopyHelper::reciveCopyProgress(QString value)
{emit qmlCopyProgress(value);//发射接收文件进度
}