不错的判断 UITextView 内容不超过20个字符串的方法

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{

if ([text isEqualToString:@"\n"]){
[self onSendBarrage:nil];
return YES;
}
NSMutableAttributedString *attrM = [[NSMutableAttributedString alloc]initWithAttributedString:textView.attributedText];
if (textView == self.textFieldBarrage)
{
if (attrM.length > MAX_INPUT_LEN) {
NSRange range = NSMakeRange(0, MAX_INPUT_LEN);
textView.attributedText = [attrM attributedSubstringFromRange:range];
}
[self fixChatButtonStateWithTextViewLength:attrM.length];
}
return YES;
}