TextField and TextView limit the length of input words

TextField and TextView limit the input length of the specific implementation method, for your reference, the specific content is as follows

TextField's restricted proxy method
You just need to have code like code in this proxy method and 16 is the length you can set yourself

 - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
 NSInteger existedLength = textField.text.length;
 NSInteger selectedLength = range.length;
 NSInteger replaceLength = string.length;
 NSInteger pointLength = existedLength - selectedLength + replaceLength;
 // More than 16 position   I can't type it in 
 if (pointLength > 16) {
  return NO;
 }else{
  return YES;
 }
 
} 

TextView's restricted proxy method

 -(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString*)text
{
 // This judgment is equivalent to textfield The click return Proxy method of 
 if ([text isEqualToString:@"\n"]) {
  [textView resignFirstResponder];
  return NO;
 }
 
 // During the input process   Determine the character input   Whether the word limit is exceeded 
 NSString *str = [NSString stringWithFormat:@"%@%@", textView.text, text];
 if (str.length > 500)
 {
  textView.text = [textView.text substringToIndex:500];
  return NO;
 }
 return YES;
}