std :: thread :: thread（ <unresolved overloaded function type> ）在Qt中

Question

The other answers I read on this website didn't seem relevant to my issue. Anyway, in my mainwindow.cpp file I have a function that needs access to the ui namespace:

 do
    {
        intrecv= recv(s1, buffer, 10000,0);
        if(intrecv > 0)
        {
            recvData = buffer;
            ui->textEdit->setText("Connection occurred.\n");
        }   
    }while(intrecv > 0);

Here are my preprocessor commands:

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <thread>
#include <string>
#include <QString>

In my mainwindow.h file I prototyped the receive function as such:

    class MainWindow : public QMainWindow
{
    Q_OBJECT
    void receiveFunction();

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

private slots:
    void on_pushButton_clicked();

    void on_lineEdit_returnPressed();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

Then, in mainwindow.cpp, I called that receive function in a thread in another function:

    void MainWindow::on_pushButton_clicked()
{
    connectFunction();
    std::thread t1(receiveFunction);
    t1.detach();
}

An example you could try to replicate my problem is make a pushbutton and a textEdit field. Have the pushbutton's slot call a function that edits the textEdit field.

edit: I forgot to mention: for my mini example, don't just have it edit the textEdit field, have it receive data and edit the textEdit field.

Answer 1

The error message seems to hint that there are multiple overloads of the reveiveFunction function, but that might be misleading (if the code above is correct). There are two things inherently wrong in the line:

std::thread t1(receiveFunction);

First is that you cannot take the address of a member function without providing the type qualification (and a member function does not decay to a pointer to member function). The second problem is that a non-static member function requires an object on which it will be called, which you are not providing. That statement can be fixed by doing:

std::thread t1(&MainWindow::receiveFunction, this);

That will correctly take the address of the member function, and provide the this pointer on which the function will be evaluated.