Qt4：连接插槽和其他形式的信号 [英] Qt4: connect slot and signal from other forms

问题描述

我有一个小问题。我想从MainWindow从AnotherWindow运行功能。我不能设置 connect（）。

I have a small problem. I want run function in MainWindow from AnotherWindow. I can't set connect() for it.

Main class: MainWindow
Other form: AnotherWindow
Function in main class: setVariable(QString)
Function in other form: btnClicked()

我现在已连接按钮信号 clicked（）：

I have now connected button signal clicked():

// In AnotherWindow.cpp
connect(ui->btnOK, SIGNAL(clicked()), this, SLOT(btnOkClicked()));

// Function in same file
void interfaceWindow::btnOkClicked() {
    /* Some actions - emit signal? */
    this->close();
}

btnOkClicked（）被声明为私有时隙。

btnOkClicked() are declared as private slot.

// In MainWindow.cpp
void MainWindow::setVariable(QString _var) {
    this->var = _var;
}

setVariable（QString）

如何从AnotherForm发送变量（从 btnOkClicked（）函数）到MainWindow（ setVariable（QString） function）？如何以及在哪里必须发送信号和连接？

How I can send variable from AnotherForm (from btnOkClicked() function) to MainWindow (setVariable(QString) function) ? How and where I must send signal and make connection?

我读了有关信号和插槽，但我的代码不工作 - 我不粘贴在这里，因为它可怕的:)

I readed about signals and slots, but my code don't work - I don't paste it here because it's terrible :)

任何帮助Qt newbie？

Any help for Qt newbie?

推荐答案

需要在MainWindow中有一个AnotherWindow的引用，反之亦然。那么你需要以下的东西：

You need to have an reference of AnotherWindow in MainWindow OR vice versa. Then you need the following things:

// AnotherWindow.h
signals:
    void buttonOkClickedSignal(QString var);

// AnotherWindow.cpp
void interfaceWindow::btnOkClicked() {
    emit buttonOkClickedSignal("The button got clicked!");
    this->close();
}

下一步取决于MainWindow是否引用AnotherWindow，反之亦然。您可以：

Next step varies based on whether MainWindow has reference to AnotherWindow or vice versa. You can either:

// AnotherWindow.cpp
connect(this, SIGNAL(buttonOkClickedSignal(QString), &mainWindow, SLOT(setVariable(QString)));

或：

// MainWindow.cpp
connect(&anotherWindow, SIGNAL(buttonOkClickedSignal(QString), this, (SLOT(setVariable(QString)));

如果你是通过信号调用槽，不管它是私有的还是公共的a href =http://qt-project.org/doc/qt-4.8/signalsandslots.html =nofollow> Qt Documentation ）。
希望这有帮助。

If you are invoking the slot through signal it shouldn't matter whether it's private or public (see Qt Documentation). Hope this helps.

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