UIImpactFeedbackGenerator not working

Question

I'm trying to use the new UIImpactFeedbackGenerator for haptic feedback, but it isn't working.

• Testing on iPhone 7
• iOS 10.1.1
• System Haptic setting is enabled

I'm using the following code example in Objective-C

UIImpactFeedbackGenerator *myGen = [[UIImpactFeedbackGenerator alloc] init];
[myGen initWithStyle:(UIImpactFeedbackStyleMedium)];
[myGen impactOccurred];
myGen = NULL;

I'm triggering it inside a UILongPressGestureRecognizer delegate.

Any idea what the problem might be?

Answer 1

I had the same issue, it turned out that while working with real time camera input, UIImpactFeedbackGenerator will not give any haptic feedback

Answer 2

I ran into the same problem, from the documentation:

...Note that calling these methods does not play haptics directly. Instead, it informs the system of the event. The system then determines whether to play the haptics based on the device, the application’s state, the amount of battery power remaining, and other factors. For example, haptic feedback is currently played only:

• On a device with a supported Taptic Engine (iPhone 7 and iPhone 7 Plus).
• When the app is running in the foreground. When the System
• Haptics setting is enabled.

I guess you just have to trust the system to known when it should fire... I didn't like this approach for obvious reasons -so used AudioServicesPlaySystemSound and k​System​Sound​ID_Vibrate:

...On some iOS devices, you can pass the k​System​Sound​ID_Vibrate constant to invoke vibration. On other iOS devices, calling this function with that constant does nothing.

Objective-C

import AudioToolbox
AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);

Swift 3

import AudioToolbox
AudioServicesPlayAlertSound(SystemSoundID(kSystemSoundID_Vibrate))