防止在Qt中触发信号 [英] Prevent Firing Signals in Qt

问题描述

我们有一个 QCheckBox 对象，当用户检查或删除检查，我们要调用一个函数，所以我们连接我们的函数 stateChanged状态）信号。另一方面，根据一些条件，我们也改变 QCheckBox 对象的状态，这会导致不需要的信号。

We have a QCheckBox object, when user checks it or removes check we want to call a function so we connect our function to stateChanged ( int state ) signal. On the other hand, according to some condition we also change the state of QCheckBox object inside code, and this causes the unwanted signal.

在某些情况下有没有办法防止触发信号？

Is there any way to prevent firing signal under some conditions?

推荐答案

http://doc.qt.nokia.com/latest/qabstractbutton.html#clicked =nofollow noreferrer> clicked 信号，因为它是只有在用户实际点击复选框时才会发生，而不是在您手动使用 setChecked 。

You can use the clicked signal because it is only emitted when the user actually clicked the check box, not when you manually check it using setChecked.

如果你不想让信号在一个具体时间，您可以使用 QObject :: blockSignals 这样：

If you just don't want the signal to be emitted at one specific time, you can use QObject::blockSignals like this:

bool oldState = checkBox->blockSignals(true);
checkBox->setChecked(true);
checkBox->blockSignals(oldState);

这种方法的缺点是，所有信号都会被阻止。但我想，在 QCheckBox 的情况下并不重要。

The downside of this approach is that all signals will be blocked. But I guess that doesn't really matter in case of a QCheckBox.

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