NSString isEqualToString 明明相等，比较失败的原因。

  NSString *messageType = [messageTypesArray objectAtIndex:1];

 if([messageType isEqualToString:@"06"]) //回复位置

         {

             NSString *additionalMessage =[messageTypesArray objectAtIndex:5];

             additionalMessage = [additionalMessage   stringByTrimmingCharactersInSet:[NSCharacterSetwhitespaceAndNewlineCharacterSet]];

      NSLog(@"additionalMessage is:%@",additionalMessage);

            if([additionalMessage  isEqualToString:@"Fail"])

            { 

              NSLog(@"TRUE");

           }

}
  NSString *messageType = [messageTypesArra