之前：

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(42.0f,10.0f,275.0f,50.0f)];
label.text = @"XXXXXX";
memoLabel.textAlignment = UITextAlignmentLeft;
memoLabel.numberOfLines = 2;
memoLabel.lineBreakMode = UILineBreakModeTailTruncation;
memoLabel.font = [UIFont systemFontOfSize:11];
memoLabel.backgroundColor = [UIColor clearColor];

IOS 6之后：

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
paragraphStyle.alignment = NSTextAlignmentLeft;
NSAttributedString *string
    = [[NSAttributedString alloc] initWithString:text
                                  attributes:[NSDictionary
                                              dictionaryWithObjectsAndKeys:[UIFont systemFontOfSize:11],NSFontAttributeName,paragraphStyle,NSParagraphStyleAttributeName,nil]];
[paragraphStyle release];
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(42.0f,50.0f)];
label.attributedText = string;
[string relase];

我希望在显示之前和之后都一样.
如何显示多行？