How to transfer data between two QT windows?

In Qt, there are several ways to transfer data between two windows.

1. Passing data through constructors: When creating the second window, pass the necessary data as a parameter to the constructor of the second window. The second window can receive and store the passed data in its constructor.

// 第一个窗口
SecondWindow secondWindow(data);
secondWindow.show();

// 第二个窗口的构造函数
SecondWindow::SecondWindow(DataType data, QWidget *parent)
    : QWidget(parent), m_data(data)
{
    // 使用传递的数据
    // ...
}

1. Passing data through member functions: You can define a public member function in the second window and pass data by calling this function.

// 第一个窗口
SecondWindow secondWindow;
secondWindow.setData(data);
secondWindow.show();

// 第二个窗口的成员函数
void SecondWindow::setData(DataType data)
{
    m_data = data;
    // 使用传递的数据
    // ...
}

1. By using signals and slots to pass data: you can define a signal and a slot function, emit the signal and pass the data in the first window, and connect the signal to the slot function in the second window to receive the data.

// 第一个窗口
emit dataPassed(data);

// 第二个窗口的槽函数
void SecondWindow::onDataPassed(DataType data)
{
    // 使用传递的数据
    // ...
}

// 连接信号与槽
connect(firstWindow, &FirstWindow::dataPassed, secondWindow, &SecondWindow::onDataPassed);

The three common methods mentioned above can be chosen based on specific needs and circumstances.