c++ - QT Cuncurrent 带邮件客户端

Question

嗨，我已经问过我的问题了here并理解为什么它不起作用，现在我通过将 Smptp 对象移动为类变量来修改源代码，但仍然不起作用。

我需要实现的是从我选择的线程发送邮件 QtConcurrent::run()这样做但点击发送按钮后插槽没有被调用。

主窗口.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "QSettings"
#include "QFuture"
#include "QtConcurrent/QtConcurrent"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    connect(ui->sendBtn, SIGNAL(clicked()),this, SLOT(test()));
    connect(ui->exitBtn, SIGNAL(clicked()),this, SLOT(close()));
    connect(ui->browseBtn, SIGNAL(clicked()), this, SLOT(browse()));
}

void MainWindow::browse()
{
    files.clear();

    QFileDialog dialog(this);
    dialog.setDirectory(QDir::homePath());
    dialog.setFileMode(QFileDialog::ExistingFiles);

    if (dialog.exec())
        files = dialog.selectedFiles();

    QString fileListString;
    foreach(QString file, files)
        fileListString.append( "\"" + QFileInfo(file).fileName() + "\" " );

    ui->file->setText( fileListString );

}
void MainWindow::test(){


    QFuture<void> f4 = QtConcurrent::run(this,&MainWindow::sendMail); // this not work
    //sendMail(); // this works
}






void MainWindow::sendMail()
{
    smtp = new Smtp(ui->uname->text(), ui->paswd->text(), ui->server->text(), ui->port->text().toInt());
    connect(smtp, SIGNAL(status(QString)), this, SLOT(mailSent(QString)));

    if( !files.isEmpty() )
        smtp->sendMail(ui->uname->text(), ui->rcpt->text() , ui->subject->text(),ui->msg->toPlainText(), files );
    else
        smtp->sendMail(ui->uname->text(), ui->rcpt->text() , ui->subject->text(),ui->msg->toPlainText());


}

void MainWindow::mailSent(QString status)
{
    if(status == "Message sent")
        QMessageBox::warning( 0, tr( "Qt Simple SMTP client" ), tr( "Message sent!\n\n" ) );

    delete smtp;
}

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

主窗口.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "smtp.h"
#include <QtWidgets/QMessageBox>
#include <QFileDialog>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:
    void sendMail();
    void mailSent(QString);
    void browse();
    void test();

private:
    Ui::MainWindow *ui;
    QStringList files;
    Smtp* smtp ;

};

#endif // MAINWINDOW_H

如果我调用 sendMail();它直接工作，但使用 QFuture<void> f4 = QtConcurrent::run(this,&MainWindow::sendMail);它不工作，不工作意味着槽没有被调用，我该如何解决这个问题？

我指的是这里的代码 https://github.com/xcoder123/SimpleSmtp_SSL_QT5/tree/master/smtp_attachements

谢谢哈里斯

Answer 1

我已经提到的解决方案 here是使用 QThread 而不是 QtConcurrent::run。Qt 文档中包含一个详细示例:http://doc.qt.io/qt-5/qthread.html#details

以下代码使此示例适应您的用例。smtp 被移动到 workerThread。主线程和 workerThread 之间的通信是使用信号和槽完成的。请注意，您不能再在 Smtp 中调用任何 GUI 相关功能(例如显示消息框等)!这必须在主线程中完成。

用户名、密码等也应该通过信号传递给 Smtp::sendMail。

主窗口.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtWidgets/QMessageBox>
#include <QFileDialog>
#include <QThread>

namespace Ui {
class MainWindow;
}

class Smtp;

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:
    void sendMailButtonClicked();
    void mailSent(QString);
    void browse();

private:
    Ui::MainWindow *ui;
    QStringList files;
    Smtp* smtp;
    QThread workerThread;
signals:
    void sendMail(const QString &from, const QString &to, const QString &subject, const QString &body, QStringList files);

};

#endif // MAINWINDOW_H

主窗口.cpp

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

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    connect(ui->sendBtn, SIGNAL(clicked()),this, SLOT(sendMailButtonClicked()));
    connect(ui->exitBtn, SIGNAL(clicked()),this, SLOT(close()));
    connect(ui->browseBtn, SIGNAL(clicked()), this, SLOT(browse()));
    smtp = new Smtp(ui->uname->text(), ui->paswd->text(), ui->server->text(), ui->port->text().toInt());
    smtp->moveToThread(&workerThread);

    connect(this, SIGNAL(sendMail(QString,QString,QString,QString,QStringList)), smtp, SLOT(sendMail(QString,QString,QString,QString,QStringList)));
    connect(smtp, SIGNAL(status(QString)), this, SLOT(mailSent(QString)));
    workerThread.start();
}

void MainWindow::browse()
{
    files.clear();

    QFileDialog dialog(this);
    dialog.setDirectory(QDir::homePath());
    dialog.setFileMode(QFileDialog::ExistingFiles);

    if (dialog.exec())
        files = dialog.selectedFiles();

    QString fileListString;
    foreach(QString file, files)
        fileListString.append( "\"" + QFileInfo(file).fileName() + "\" " );

    ui->file->setText( fileListString );

}

void MainWindow::mailSent(QString status)
{
    if(status == "Message sent")
        QMessageBox::warning( 0, tr( "Qt Simple SMTP client" ), tr( "Message sent!\n\n" ) );
}

MainWindow::~MainWindow()
{
    workerThread.quit();
    workerThread.wait();
    delete ui;
}

void MainWindow::sendMailButtonClicked()
{
    emit sendMail(ui->uname->text(), ui->rcpt->text() , ui->subject->text(),ui->msg->toPlainText(), files );
}

在smtp.h中:设置sendMail为槽:

public slots:
    void sendMail( const QString &from, const QString &to,
                   const QString &subject, const QString &body,
                   QStringList files = QStringList());