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）
// 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：
#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frameUIKeyboardFrameEndUserInfoKey = 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double duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];// 键盘的frameCGRect 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
@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文件中实现（重写setter 和 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有需要的同行可以直接拿来用
当你能爱的时候就不要放弃爱
