UISwitch setOn(:, animated:) does not work as document

问题

As Apple's document write, UISwitch's function setOn(on: Bool, animated: Bool) does not send action. It works fine before iOS 10, but it will send action after I call it in iOS 10. I call it in "ValueChanged" event to force switch back, so I got this event action twice. is it a bug in iOS 10?

回答1:

DispatchQueue.main.async {
    sender.setOn(flag, animated: animated)
}

it works for me in Xcode 8.

but call UISwitch.setOn(_:animated:) directly on main thread doesn't work.

Update

thanks to @codiction:

UISwitch.setOn(_:animated:) can be called direclty on main thread, but can't be called directly in UISwitch ValueChanged action on iOS 10.

回答2:

The following solution resolves that issue. You should dispatch_async only if trying to call [UISwitch setOn:] within the action callback of that switch itself.

dispatch_async(dispatch_get_main_queue(), ^{

    [switch setOn:YES animated:YES];
});

回答3:

I found these solutions to partially work. However, when I used switch.setOn(false, animated: true) the onTint color would appear white in the off position. I'm assuming this is a bug but I worked around this by using this:

switch.setOn(false, animated: true)
switch.onTintColor = .clear

Don't forget to reset the onTint color when you're ready to allow the switch to be toggled on, if applicable.

switch.onTintColor = <your custom color> // Use nil to use the default onTint for UISwitch

Hopefully this helps save someone a little time.

来源：https://stackoverflow.com/questions/39566361/uiswitch-seton-animated-does-not-work-as-document