iOS实现聊天输入框功能

- (void)viewDidLoad {
  [super viewDidLoad];
  self.view.backgroundColor = [UIColor colorWithRed:0.92 green:0.92 blue:0.92 alpha:1.00];
  
  self.keyView = [[DKSKeyboardView alloc] initWithFrame:CGRectMake(0, K_Height - 51, K_Width, 51)];
  //设置代理方法
  self.keyView.delegate = self;
  [self.view addSubview:_keyView];
}

#import @protocol DKSKeyboardDelegate @optional //非必实现的方法
/**
 点击发送时输入框内的文案
 @param textStr 文案
 */
- (void)textViewContentText:(NSString *)textStr;
/**
 键盘的frame改变
 */
- (void)keyboardChangeFrameWithMinY:(CGFloat)minY;
@end
@interface DKSKeyboardView : UIView @property (nonatomic, weak) id delegate;
@end

//键盘将要出现
- (void)keyboardWillShow:(NSNotification *)notification {
  [self removeBottomViewFromSupview];
  NSDictionary *userInfo = notification.userInfo;
  CGRect endFrame = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
  //获取键盘的高度
  self.keyboardHeight = endFrame.size.height;
  
  //键盘的动画时长
  CGFloat duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
  [UIView animateWithDuration:duration delay:0 options:[notification.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue] animations:^{
    self.frame = CGRectMake(0, endFrame.origin.y - self.backView.height - StatusNav_Height, K_Width, self.height);
    [self changeTableViewFrame];
  } completion:nil];
}

- (void)keyboardWillHide:(NSNotification *)notification {
  //如果是弹出了底部视图时
  if (self.moreClick || self.emojiClick) {
    return;
  }
  [UIView animateWithDuration:0.25 animations:^{
    self.frame = CGRectMake(0, K_Height - StatusNav_Height - self.backView.height, K_Width, self.backView.height);
    [self changeTableViewFrame];
  }];
}

- (void)moreBtn:(UIButton *)btn {
  self.emojiClick = NO; //主要是设置表情按钮为未点击状态
  if (self.moreClick == NO) {
    self.moreClick = YES;
    //回收键盘
    [self.textView resignFirstResponder];
    [self.emojiView removeFromSuperview];
    self.emojiView = nil;
    [self addSubview:self.moreView];
    //改变更多、self的frame
    [UIView animateWithDuration:0.25 animations:^{
      self.moreView.frame = CGRectMake(0, self.backView.height, K_Width, bottomHeight);
      self.frame = CGRectMake(0, K_Height - StatusNav_Height - self.backView.height - bottomHeight, K_Width, self.backView.height + bottomHeight);
      [self changeTableViewFrame];
    }];
  } else { //再次点击更多按钮
    //键盘弹起
    [self.textView becomeFirstResponder];
  }
}

- (void)changeFrame:(CGFloat)height {
  CGRect frame = self.textView.frame;
  frame.size.height = height;
  self.textView.frame = frame; //改变输入框的frame
  //当输入框大小改变时，改变backView的frame
  self.backView.frame = CGRectMake(0, 0, K_Width, height + (viewMargin * 2));
  self.frame = CGRectMake(0, K_Height - self.backView.height - self.keyboardHeight, K_Width, self.backView.height);
  //改变更多按钮、表情按钮的位置
  self.emojiBtn.frame = CGRectMake(viewMargin, self.backView.height - viewHeight - viewMargin, viewHeight, viewHeight);
  self.moreBtn.frame = CGRectMake(self.textView.maxX + viewMargin, self.backView.height - viewHeight - viewMargin, viewHeight, viewHeight);
  //主要是为了改变VC的view的frame
  if (self.delegate && [self.delegate respondsToSelector:@selector(changeFrameWithMinY:)]) {
    [self.delegate changeFrameWithMinY:self.minY];
  }
}