防止在 Qt 中触发信号

Prevent Firing Signals in Qt(防止在 Qt 中触发信号)

问题描述

我们有一个 QCheckBox 对象，当用户检查它或删除检查时，我们想要调用一个函数，因此我们将我们的函数连接到 stateChanged ( int state ) 信号.另一方面，根据某些情况，我们也在代码中改变了 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.

在某些情况下有什么办法可以防止发射信号吗?

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

推荐答案

您可以使用 clicked 信号，因为它仅在用户实际单击复选框时发出，而不是在您使用 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.

如果您只是不想在某个特定时间发出信号，可以使用 QObject::blockSignals 像这样:

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将被阻塞.但我想这在 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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