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> clicked
信号,因为它仅在用户实际点击复选框,而不是使用 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
.
如果您不想在一个特定时间发出信号,可以使用 QObject :: blockSignals
如下:
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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