How to disable/enable the sleep mode programmatically in iOS?

Question

You can disable the idle timer as follows;

In Objective-C:

[UIApplication sharedApplication].idleTimerDisabled = YES;

In Swift:

UIApplication.sharedApplication().idleTimerDisabled = true

In Swift 3.0 & Swift 4.0:

UIApplication.shared.isIdleTimerDisabled = true

Set it back to NO or false to re-enable sleep mode.

For example, if you need it until you leave the view you can set it back by overriding the viewWillDisappear:

override func viewWillDisappear(_ animated: Bool) {
    UIApplication.shared.isIdleTimerDisabled = false
}

More about UIApplication Class.