I am using this method to ask user for the calendar permission requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error) but what i want is that when user clicks on Button named as GrantPermission, then the permission should be granted without showing the alertView which is of IOS builtin, is there any way to do this?
I want to do this because when user clicks on Dont Allow then i show a alertView which says that user have to manually turn on permission from settings and when user manually turns on this permission then the app crashes.
There is no way to grant permission without displaying the native alert view, as it provides an added level of security (without it developers would just be programatically granting permission to everything).
If you want to mitigate against getting into the situation where the user needs to manually grant permission from the Settings app you could display a "pre-permission" alert where you offer the user some information as to why they might want to allow it, followed by actually asking the system for permission which will in turn display the built in alert.
FWIW This isn't my idea, nor is it that new. This TechCrunch article goes into a lot more detail about the UX of asking for permissions on iOS.
Note that you could still end up in the situation where the user needs to manually grant permission - if they "accept" your alert but deny the actual system alert. In this case you will need to figure out why your app is crashing, maybe post another question regarding that.