iOS开发之监听键盘高度的变化分类： ios技术 2015-04-21 12:04 233人阅读评论(0) 收藏

最近做的项目中，有一个类似微博中的评论转发功能，屏幕底端有一个输入框用textView来做，当textView成为第一响应者的时候它的Y值随着键盘高度的改变而改变，保证textView紧贴着键盘，但又不会被键盘挡住。

下面是我实现的方法：（利用通知）

123456789101112 // 键盘通知 // 键盘的frame发生改变时发出的通知（位置和尺寸） // UIKeyboardWillChangeFrameNotification // UIKeyboardDidChangeFrameNotification // 键盘显示时发出的通知 // UIKeyboardWillShowNotification // UIKeyboardDidShowNotification // 键盘隐藏时发出的通知 // UIKeyboardWillHideNotification // UIKeyboardDidHideNotification [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];//在这里注册通知

下面是监听通知：

12345678910111213141516171819202122232425262728293031323334353637 #pragma mark - 监听方法/** * 键盘的frame发生改变时调用（显示、隐藏等） */- (void)keyboardWillChangeFrame:(NSNotification *)notification{ // if (self.picking) return; /** notification.userInfo = @{ // 键盘弹出\隐藏后的frame UIKeyboardFrameEndUserInfoKey = NSRect: {{0, 352}, {320, 216}}, // 键盘弹出\隐藏所耗费的时间 UIKeyboardAnimationDurationUserInfoKey = 0.25, // 键盘弹出\隐藏动画的执行节奏（先快后慢，匀速） UIKeyboardAnimationCurveUserInfoKey = 7 } */ NSDictionary *userInfo = notification.userInfo; // 动画的持续时间 doubleduration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]; // 键盘的frame CGRect keyboardF = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue]; // 执行动画 [UIView animateWithDuration:duration animations:^{ // 工具条的Y值 == 键盘的Y值 - 工具条的高度 if(keyboardF.origin.y > self.view.height) {// 键盘的Y值已经远远超过了控制器view的高度 self.toolbar.y = self.view.height - self.toolbar.height;//这里的<span style="background-color: rgb(240, 240, 240);">self.toolbar就是我的输入框。</span> }else{ self.toolbar.y = keyboardF.origin.y - self.toolbar.height; } }];}

当然，这里我为UIView写了一个类别，实现如下：

.h文件中声明

12345678910 @interfaceUIView (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文件中实现（重写setter 和 getter）

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798 @implementationUIView (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{ returnself.frame.origin.x;} - (CGFloat)y{ returnself.frame.origin.y;} - (void)setCenterX:(CGFloat)centerX{ CGPoint center = self.center; center.x = centerX; self.center = center;} - (CGFloat)centerX{ returnself.center.x;} - (void)setCenterY:(CGFloat)centerY{ CGPoint center = self.center; center.y = centerY; self.center = center;} - (CGFloat)centerY{ returnself.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{ returnself.frame.size.height;} - (CGFloat)width{ returnself.frame.size.width;} - (void)setSize:(CGSize)size{ CGRect frame = self.frame; frame.size = size; self.frame = frame;} - (CGSize)size{ returnself.frame.size;} - (void)setOrigin:(CGPoint)origin{ CGRect frame = self.frame; frame.origin = origin; self.frame = frame;} - (CGPoint)origin{ returnself.frame.origin;}@end

有需要的朋友可以直接用

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