Qt C++ 子线程访问主线程数据和方法

Widget.h


class SaveThread;//前置声明
class Widget : public QWidget
{
    Q_OBJECT
signals:
    void preper_save(Widget *);
public:
    friend class SaveThread;//将SaveThread类声明为友元
private:
    SaveThread *s_thread;//声明SaveThread对象，s_thread.start()写在onUDPSocketReadyRead()函数中，收到UDP信号后发送信号，并启动线程

 　 bool savedata_excel();//用于保存数据的函数 private slots: void onUDPSocketReadyRead();//读取socket传入的数据

#include "savethread.h" //包含头文件，不然编译器会报错，没有在.h中声明，因为也会报错
Widget::Widget(QWidget *parent) :QWidget(parent),ui(new Ui::Widget)
{
    s_thread=new SaveThread();//给子线程类对象分配地址


    connect(this,SIGNAL(preper_save(Widget *)),s_thread,SLOT(getaddress(Widget *)));//传递主线程指针地址
    connect(ui->savebtn,SIGNAL(clicked()),this,SLOT(savedata_excel()));//主线程中点击按钮之后保存数据

}

void Widget::onUDPSocketReadyRead()
{
    while(udpSocket->hasPendingDatagrams())
    {
        QByteArray   datagram;
        datagram.resize(udpSocket->pendingDatagramSize());

        QHostAddress    peerAddr;
        quint16 peerPort;
        udpSocket->readDatagram(datagram.data(),datagram.size(),&peerAddr,&peerPort);
        QString str=datagram.data();

        QString peer="[From "+peerAddr.toString()+":"+QString::number(peerPort)+"] ";
        ui->plainTextEdit->appendPlainText(peer+str);

        if(str.mid(0,4)=="+PLS")
        {
            shotnum=str;
            emit preper_save(this);//UDP收到信号只有，将主线程地址传递给子线程
            s_thread->start();//子线程开始
        }
        else
            return;
    }
}

bool Widget::savedata_excel()
{
    qDebug()<<"这是主线程的保存数据";
    QString fileName = QFileDialog::getSaveFileName(this,"保存",
                        QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation),"Excel 文件(*.xls *.xlsx)");
    if(fileName!="")
    {
        QAxObject *excel = new QAxObject;
        excel->setControl("Excel.APPlication");

        excel->dynamicCall("SetVisible (bool Visible)","false");//不显示窗体
        excel->setProperty("DisplayAlerts", false);//不显示任何警告信息。如果为true那么在关闭是会出现类似“文件已修改，是否保存”的提示
        QAxObject *workbooks = excel->querySubObject("WorkBooks");//获取工作簿集合
        workbooks->dynamicCall("Add");//新建一个工作簿
        QAxObject *workbook = excel->querySubObject("ActiveWorkBook");//获取当前工作簿
        QAxObject *worksheet = workbook->querySubObject("Worksheets(int)", 1);

        if(channel1->on_off)
        {
            QVariant var=datatovariant(model1);
            int i = model1->rowCount();
            QString str="A3:C"+QString::number(2+i);
            QAxObject *range=worksheet->querySubObject("Range(const QString&)",str);
            range->setProperty("Value",var);
            range->querySubObject("Interior")->setProperty("Color", QColor(255, 255, 165));
        }

        workbook->dynamicCall("SaveAs(const QString&)",QDir::toNativeSeparators(fileName));//保存至fileName
        workbook->dynamicCall("Close()");//关闭工作簿
        excel->dynamicCall("Quit()");//关闭excel
        flagnumber=0;
        delete excel;
        excel=nullptr;
        QMessageBox::information(this,tr("提示"),tr("数据已保存"));
        return true;
    }
    else
        return false;
}

SaveThread.h


#include "widget.h"//包含Widget类的头文件
#pragma execution_character_set("utf-8")
class SaveThread : public QThread
{
    Q_OBJECT
protected:
    void  run() Q_DECL_OVERRIDE;  //线程任务
public:
    SaveThread();
private slots:
    void getaddress(Widget *);//槽函数，用于接收指针
private:
    Widget *w;
};

SaveThread.cpp


void SaveThread::run()
{
    qDebug()<<"线程开始";
    QString strpath=w->fileName;
    strpath.append(w->shotnum);
    qDebug()<<strpath;
    if(strpath!="")
    {
        //QMessageBox::information(this,tr("提示"),tr("正在保存数据，请稍等"));
        QAxObject *excel = new QAxObject;
        excel->setControl("Excel.APPlication");

        excel->dynamicCall("SetVisible (bool Visible)","false");//不显示窗体
        excel->setProperty("DisplayAlerts", false);//不显示任何警告信息。如果为true那么在关闭是会出现类似“文件已修改，是否保存”的提示
        QAxObject *workbooks = excel->querySubObject("WorkBooks");//获取工作簿集合
        workbooks->dynamicCall("Add");//新建一个工作簿
        QAxObject *workbook = excel->querySubObject("ActiveWorkBook");//获取当前工作簿
        QAxObject *worksheet = workbook->querySubObject("Worksheets(int)", 1);


        if(w->channel1->on_off)//每个通道对应的结构体中有一个值on_off来判断通道是否打开
        {
            QVariant var=w->datatovariant(w->model1);
            int i = w->model1->rowCount();
            QString str="A3:C"+QString::number(2+i);
            QAxObject *range=worksheet->querySubObject("Range(const QString&)",str);
            range->setProperty("Value",var);
            range->querySubObject("Interior")->setProperty("Color", QColor(255, 255, 165));
        }

        workbook->dynamicCall("SaveAs(const QString&)",QDir::toNativeSeparators(strpath));//保存至fileName
        workbook->dynamicCall("Close()");//关闭工作簿
        excel->dynamicCall("Quit()");//关闭excel
        w->flagnumber=0;
        delete excel;
        excel=nullptr;
     }
    this->quit(); 
    qDebug()<<"线程结束";
}

void SaveThread::getaddress(Widget *p)
{
    w=p;//此行代码就使得w有了内存，而且和主线程对象地址一样
}