UITextField,UITextView字数限制

主要是使用他们的两个代理方法

//标题限制在 30个字以内 - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{        if (range.location>=30)        {            UIAlertView *alertNums = [[UIAlertView alloc]initWithTitle:@"输入提示" message:@"标题字数限制在30字以内！" delegate:self cancelButtonTitle:nil otherButtonTitles:@"确定", nil];            [alertNums show];            return  NO;        }        else        {            return YES;        }   }//内容限制在100个字以内;- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{    if (range.location>=100)    {        UIAlertView *alertNums = [[UIAlertView alloc]initWithTitle:@"输入提示" message:@"内容限制在100字以内！" delegate:self cancelButtonTitle:nil otherButtonTitles:@"确定", nil];        [alertNums show];        return  NO;    }    else    {        return YES;    }}