Hide keyboard in iOS for any view?

Question

There are similar questions but they are all about cases when they know which view is editing.

In my case I have a local notification and I want to hide keyboard when app becomes active with it.

In the same time I have a complex navigation which involves MMDrawerController and modal views. So I can't just take topmost view controller and iterate its subviews.

So could you explain how to hide keyboard if I don't know the view currently viewing?

Answer 1

Add a category to UIResponder: Get the current first responder without using a private API

static __weak id currentFirstResponder;

@implementation UIResponder (FirstResponder)

+(id)currentFirstResponder {
    currentFirstResponder = nil;
    [[UIApplication sharedApplication] sendAction:@selector(findFirstResponder:) to:nil from:nil forEvent:nil];
    return currentFirstResponder;
}

-(void)findFirstResponder:(id)sender {
    currentFirstResponder = self;
}

+(void)hideKeyboard {
    id firstResponder = [UIResponder currentFirstResponder];
    if([firstResponder respondsToSelector:@selector(endEditing:)]) {
        [firstResponder endEditing:YES];
    }
}

@end

Import the category and do below in your action to hide keyboard:

if([[UIResponder currentFirstResponder] respondsToSelector:@selector(endEditing:)]) {
    [[UIResponder currentFirstResponder] endEditing:YES];
} 

By this solution, you do not need to know the view currently viewing. Just get the current first responder and call endEdition:. For when editable view become editing, it will become first responder.

EDIT:

With Vyachaslav Gerchicov's suggestion, I add hideKeyboard method in the category. And just call [UIResponder hideKeyboard];.