IOS TextFiled与TextView 键盘的收起以及处理键盘遮挡

- (void)viewDidLoad { 
  [super viewDidLoad]; 
 
  [self setUpForDismissKeyboard];   
} 

#pragma mark - 回收任何空白区域键盘事件 
- (void)setUpForDismissKeyboard { 
  NSNotificationCenter *nc = [NSNotificationCenter defaultCenter]; 
  UITapGestureRecognizer *singleTapGR = 
  [[UITapGestureRecognizer alloc] initWithTarget:self 
                      action:@selector(tapAnywhereToDismissKeyboard:)]; 
  NSOperationQueue *mainQuene =[NSOperationQueue mainQueue]; 
  [nc addObserverForName:UIKeyboardWillShowNotification 
          object:nil 
           queue:mainQuene 
        usingBlock:^(NSNotification *note){ 
          [self.view addGestureRecognizer:singleTapGR]; 
        }]; 
  [nc addObserverForName:UIKeyboardWillHideNotification 
          object:nil 
           queue:mainQuene 
        usingBlock:^(NSNotification *note){ 
          [self.view removeGestureRecognizer:singleTapGR]; 
        }]; 
} 
 
- (void)tapAnywhereToDismissKeyboard:(UIGestureRecognizer *)gestureRecognizer { 
  //此method会将self.view里所有的subview的first responder都resign掉 
  [self.view endEditing:YES]; 
} 

#pragma mark - TextView 代理方法 
 
-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text 
{ 
  if ([text isEqualToString:@"\n"]) { 
     
    [self.workLogTextView resignFirstResponder]; 
     
    return NO; 
  } 
   
  return YES; 
} 

#pragma mark 键盘遮挡 
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView { 
  if (self.userInfo.isPhone4) { 
    CGFloat offset_y = 0.f; 
    if (textView.tag == CALL_CONTENT_TEXTFIRLD) { 
      offset_y = 100.f; 
    } 
    CGPoint point = self.BackScrollView.contentOffset; 
    point = CGPointMake(point.x, offset_y); 
    [UIView animateWithDuration:0.25 animations:^{ 
      self.BackScrollView.contentOffset = point; 
    }]; 
  } 
  return YES; 
} 
 
 
- (BOOL)textViewShouldEndEditing:(UITextView *)textView{ 
  if (self.userInfo.isPhone4) { 
    CGFloat offset_y = 0.f; 
    if (textView.tag == CALL_CONTENT_TEXTFIRLD) { 
      offset_y = 100.f; 
    } 
    CGPoint point = self.BackScrollView.contentOffset; 
    point = CGPointMake(point.x, 0); 
    [UIView animateWithDuration:0.25 animations:^{ 
      self.BackScrollView.contentOffset = point; 
    }]; 
  } 
  return YES; 
}