iOS Global processing keyboard events

Transferred from: http://www.cnblogs.com/xinus/archive/2013/01/22/ios-keybord-notification.html

1. Register for notification of keyboard events
   

       [[Nsnotificationcenter Defaultcenter] addobserver:self selector: @selector (                                               Keyboardwillshow:) name:uikeyboardwillshownotification        Object:nil]; [[Nsnotificationcenter Defaultcenter] addobserver:self selector: @selector (keyb                                               Oardshow:) name:uikeyboarddidshownotification        Object:nil]; [[Nsnotificationcenter Defaultcenter] addobserver:self selector: @selector (keyb                                               Oardwillhide:) name:uikeyboardwillhidenotification        Object:nil]; [[Nsnotificationcenter Defaultcenter] addobserver:self selector: @selector (keyb        Oardhide:)                                         Name:uikeyboarddidhidenotification Object:nil];

2. In the callback that the keyboard will appear and hide, add the animation.
   

   -(void) Keyboardwillshow: (nsnotification *) Notif {if (Self.hidden = = YES) {return;    } cgrect rect = [[Notif.userinfo Objectforkey:uikeyboardframeenduserinfokey] cgrectvalue];    CGFloat y = rect.origin.y;    [UIView Beginanimations:nil Context:nil];    [UIView setanimationduration:0.25];    Nsarray *subviews = [self subviews];        For (UIView *sub in subviews) {cgfloat Maxy = Cgrectgetmaxy (sub.frame);        if (Maxy > y-2) {sub.center = Cgpointmake (Cgrectgetwidth (self.frame)/2.0, Sub.center.y-maxy + y-2); }} [UIView commitanimations];}    -(void) Keyboardshow: (nsnotification *) Notif {if (Self.hidden = = YES) {return;    }}-(void) Keyboardwillhide: (nsnotification *) Notif {if (Self.hidden = = YES) {return;    } [UIView Beginanimations:nil context:nil];    [UIView setanimationduration:0.25];    Nsarray *subviews = [self subviews]; For (UIView *sub in subviews) {if (Sub.center.y < CGREctgetheight (self.frame)/2.0) {sub.center = Cgpointmake (Cgrectgetwidth (self.frame)/2.0, CGRectGetHeight (self.f        Rame)/2.0); }} [UIView commitanimations];}    -(void) Keyboardhide: (nsnotification *) Notif {if (Self.hidden = = YES) {return; }}

iOS Global processing keyboard events