UILabel auto height

.h

 @interface ViewController : UIViewController {

    IBOutlet UILabel *label;

   }

.m

 - (void)viewDidLoad {
   [super viewDidLoad];

 //  UILabel *label = [[UILabel alloc] init];
   label.backgroundColor = [UIColor lightGrayColor];

   NSString *lorum = @"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Nam liber te conscient to factor tum poen legum odioque civiuda.";

   //for use labrect with UITextView you set the font of UITextView:
   //label.font = [UIFont systemFontOfSize:17];      

   CGSize maxSize = CGSizeMake(320, 410);
   CGRect labrect = [lorum boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:label.font} context:Nil];

   label.text = lorum;
   //for use UITextView you should comment the line under
   label.numberOfLines = 0;
   label.frame = CGRectMake(0, 30, 320, labrect.size.height);

 //  [self.view addSubview:label];

  };