如何在UIViewController中处理键盘快捷键

Question

I am trying to add a keyboard shortcut for use with an external Bluetooth Keyboard to a UIViewController with no UITextField or UITextView on it. So far I tried the following with no success

- (BOOL)canBecomeFirstResponder {
    return YES;
}

- (NSArray *)keyCommands {
    return @[
             [UIKeyCommand keyCommandWithInput:@"e" modifierFlags:UIKeyModifierCommand action:@selector(handleShortcut:)]];
}

- (void)handleShortcut:(id)sender
{
    NSLog(@"%s",__FUNCTION__);
}

I also stumbled over this post with a workaround but it didn't work for me. Any ideas how to handle shortcuts in a UIViewController with not textfields on it?

Answer 1

Make a subclass of UIView. Add methods to it:

- (BOOL)canBecomeFirstResponder {
    return YES;
}

- (NSArray<UIKeyCommand *>*)keyCommands {
    return @[
//example shortcut CTRL+Cmnd+1
             [UIKeyCommand keyCommandWithInput:@"1" modifierFlags:UIKeyModifierCommand | UIKeyModifierControl action:@selector(pressed:)]
];
        }

Add needed selector in ("pressed:" in my case)

Set your ViewController view class - your subclass.

Result - "2015-11-30 17:34:28.815 ProjectName[5204:2899520] 1"

Answer 2

A slightly old question but since Google has this link high when searching for keyboard shortcuts for a UIViewController , here's the current (Nov 2017) answer:

UIViewController now has a simple method called -addKeyCommand: so just add your command(s) to your view controller using this method and you are good to go.