键盘输入框联动效果

@interface FACommentKeyBoard()<UITextViewDelegate>
//动画时间
@property (nonatomic, assign) CGFloat animationDuration;
//键盘的偏移量
@property (nonatomic, assign) CGFloat offsetMarginY;
//设置最大行数
@property(nonatomic,assign)int maxLine;
//上下间距
@property(nonatomic,assign)CGFloat topOrBottomEdge;
//键盘的Y值
@property(nonatomic,assign)CGFloat keyboardY;
@end

@implementation FACommentKeyBoard
-(instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];
          self.maxLine = 3;
          self.topOrBottomEdge = 16;
    }
    return self;
}
-(instancetype)initCommentKeyBoard{
    self = [super init];
      if (self) {
          self.frame = [UIScreen mainScreen].bounds;
          self.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.1];
          UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(dismissCommentKeyBoard)];
          [self addGestureRecognizer:tap];
          [self addSubview:self.toolBar];
          [self.toolBar addSubview:self.textView];
          [self.toolBar addSubview:self.sendBtn];
    }
    return self;
}
-(UIView *)toolBar{
    if (!_toolBar) {
        _toolBar = [[UIView alloc]init];
        _toolBar.backgroundColor = [UIColor colorWithHexString:@"#f5f5f5"];
        _toolBar.frame = CGRectMake(0, SCREEN_HEIGHT, SCREEN_WIDTH, 66);
        [self addSubview:_toolBar];
    }
    return _toolBar;
}

-(UITextView *)textView{
    if (!_textView) {
        _textView = [[UITextView alloc]init];
        _textView.frame = CGRectMake(16, 16, SCREEN_WIDTH-32-64, 34);
        _textView.delegate = self;
        _textView.contentInset = UIEdgeInsetsMake(0, 15, 0, 15);
        _textView.text = @"差点就类似的的暗示大";
        _textView.layer.borderWidth = 0.5;
        _textView.layer.cornerRadius = 20;
        _textView.layer.borderColor = [UIColor colorWithHexString:@"#E5E5E5"].CGColor;
        _textView.textColor = [UIColor colorWithHexString:@"#000000"];
        if (@available(iOS 11.0, *)) {
         _textView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        }
        _textView.font = [UIFont systemFontOfSize:15.0];
    }
    return _textView;
}
-(UIButton *)sendBtn{
    if (!_sendBtn) {
        _sendBtn = [UIButton buttonWithType:UIButtonTypeCustom];
        _sendBtn.frame = CGRectMake(CGRectGetMaxX(self.textView.frame)+20.f, 36-8, 40, 16);
        _sendBtn.contentHorizontalAlignment = 0;
        [_sendBtn setTitle:@"发送" forState:UIControlStateNormal];
        [_sendBtn setTitleColor:[UIColor colorWithHexString:@"#999999"] forState:UIControlStateNormal];
        _sendBtn.titleLabel.font = [UIFont systemFontOfSize:16.0];
    }
    return _sendBtn;
}
#pragma mark--显示键盘
-(void)showCommentKeyBoard{
    
    UIWindow *rootWindow = [UIApplication sharedApplication].keyWindow;
    [rootWindow addSubview:self];
    [UIView animateWithDuration:0.2 animations:^{
       self.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.7];
    }];
}
#pragma mark--键盘消失
- (void)dismissCommentKeyBoard
{
    self.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.2];
    [UIView animateWithDuration:0.2
                          delay:0.0
    options:UIViewAnimationOptionCurveEaseInOut
    animations:^{
     }
    completion:^(BOOL finished){
         [self.toolBar removeFromSuperview];
         [self removeFromSuperview];
     }];
}
#pragma mark--监听键盘相应
- (void)keyboardWillChangeFrame:(NSNotification *)notification
{
     CGRect keyboardFrame = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
     CGFloat keyboardHeight = keyboardFrame.size.height;
     CGFloat keyboardAnimaitonDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
     self.animationDuration = keyboardAnimaitonDuration;
     NSInteger option = [notification.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue];
    self.keyboardY = keyboardFrame.origin.y;
    //判断键盘是否出现
     BOOL isKeyBoardHidden = SCREEN_HEIGHT == keyboardFrame.origin.y;
      self.offsetMarginY = isKeyBoardHidden ? SCREEN_HEIGHT - self.toolBar.height :SCREEN_HEIGHT - self.toolBar.height - keyboardHeight;
    //修改工具条的尺寸
    [UIView animateKeyframesWithDuration:self.animationDuration delay:0 options:option animations:^{
     self.toolBar.frame = CGRectMake(0, self.offsetMarginY, SCREEN_WIDTH, 72);
    } completion:nil];
}
#pragma mark--监听输入框发生的改变
-(void)textViewDidChange:(UITextView *)textView{
  //行间距
  NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.lineSpacing = 3;// 字体的行间距
    NSDictionary *attributes = @{NSFontAttributeName:[UIFont systemFontOfSize:15],NSParagraphStyleAttributeName:paragraphStyle};
    textView.attributedText = [[NSAttributedString alloc] initWithString:textView.text attributes:attributes];
   //计算高度
   CGFloat contentSizeH = self.textView.contentSize.height;
   CGFloat lineH = self.textView.font.lineHeight;
   CGFloat maxHeight = ceil(lineH * self.maxLine + textView.textContainerInset.top + textView.textContainerInset.bottom);
    if (contentSizeH <= maxHeight) {
           self.textView.height = contentSizeH;
       }else{
           self.textView.height = maxHeight;
     }
    //滚动到选择区域位置
    [textView scrollRangeToVisible:NSMakeRange(textView.selectedRange.location, 1)];
    //保证圆角效果
    textView.layer.cornerRadius = self.textView.height/2;
    //修改父视图
    CGFloat totalH = ceil(self.textView.height) + 2 * self.topOrBottomEdge;
    [UIView animateWithDuration:0.3 animations:^{
     self.toolBar.frame = CGRectMake(0, self.keyboardY- totalH, self.width, totalH);
    }];
}