IOS development-listening for changes in keyboard height

IOS development-listening for changes in keyboard height

In a recent project, there is a comment forwarding function similar to that in Weibo. At the bottom of the screen, there is an input box that uses textView, when textView becomes the first responder, its Y value changes with the keyboard height, ensuring that textView is closely bound to the keyboard, but not blocked by the keyboard.

The following is my Implementation Method: (using notifications)

// Keyboard notification // the notification (location and size) issued when the frame of the keyboard changes) // notify // notification sent when the keyboard is displayed // UIKeyboardWillShowNotification // UIKeyboardDidShowNotification // notification sent when the keyboard is hidden // notify [[nsicationicationcenter defadefa] addObserver: self selector: @ selector (keyboardWillChangeFrame :) name: UIKeyboardWillChangeFrameNotification object: nil]; // register a notification here

The following is a listener notification:

# Pragma mark-listener method/*** call (display, hide, etc.) when the frame of the keyboard changes */-(void) keyboardWillChangeFrame :( NSNotification *) notification {// if (self. picking) return;/** notification. userInfo ={ // The keyboard pops up \ The Hidden frame UIKeyboardFrameEndUserInfoKey = NSRect: {0,352 },{ 320,216 }}, // keyboard pop-up \ hide time consumed UIKeyboardAnimationDurationUserInfoKey = 0.25, // keyboard pop-up \ hide the animation execution speed (Fast first, slow, uniform speed) UIKeyboardAnimationCurveUserInfoKey = 7} */NSDictio Nary * userInfo = notification. userInfo; // animation duration double duration = [userInfo [UIKeyboardAnimationDurationUserInfoKey] doubleValue]; // The frame CGRect keyboardF of the keyboard = [userInfo [UIKeyboardFrameEndUserInfoKey] CGRectValue]; // execute the animation [UIView animateWithDuration: duration animations: ^ {// Y value of the toolbar = Y value of the keyboard-height of the toolbar if (keyboardF. origin. y> self. view. height) {// The Y value of the keyboard has far exceeded the height of the controller view self. toolbar. y = self. v Iew. height-self. toolbar. height; // here, self. toolbar is my input box.} Else {self. toolbar. y = keyboardF. origin. y-self. toolbar. height;}];}

Of course, here I write a category for UIView, which is implemented as follows:

. H file Declaration

@interface UIView (Extension)@property (nonatomic, assign) CGFloat x;@property (nonatomic, assign) CGFloat y;@property (nonatomic, assign) CGFloat width;@property (nonatomic, assign) CGFloat height;@property (nonatomic, assign) CGFloat centerX;@property (nonatomic, assign) CGFloat centerY;@property (nonatomic, assign) CGSize size;@property (nonatomic, assign) CGPoint origin;@end

. M file implementation (rewrite setter and getter)

@implementation UIView (Extension)- (void)setX:(CGFloat)x{    CGRect frame = self.frame;    frame.origin.x = x;    self.frame = frame;}- (void)setY:(CGFloat)y{    CGRect frame = self.frame;    frame.origin.y = y;    self.frame = frame;}- (CGFloat)x{    return self.frame.origin.x;}- (CGFloat)y{    return self.frame.origin.y;}- (void)setCenterX:(CGFloat)centerX{    CGPoint center = self.center;    center.x = centerX;    self.center = center;}- (CGFloat)centerX{    return self.center.x;}- (void)setCenterY:(CGFloat)centerY{    CGPoint center = self.center;    center.y = centerY;    self.center = center;}- (CGFloat)centerY{    return self.center.y;}- (void)setWidth:(CGFloat)width{    CGRect frame = self.frame;    frame.size.width = width;    self.frame = frame;}- (void)setHeight:(CGFloat)height{    CGRect frame = self.frame;    frame.size.height = height;    self.frame = frame;}- (CGFloat)height{    return self.frame.size.height;}- (CGFloat)width{    return self.frame.size.width;}- (void)setSize:(CGSize)size{    CGRect frame = self.frame;    frame.size = size;    self.frame = frame;}- (CGSize)size{    return self.frame.size;}- (void)setOrigin:(CGPoint)origin{    CGRect frame = self.frame;    frame.origin = origin;    self.frame = frame;}- (CGPoint)origin{    return self.frame.origin;}@end

Can be used directly by peers in need