ios – OBJ-C：如何释放从方法返回的对象？

-(void)returnHeaderView
{
  self.headerView=[[UIView alloc]init];
  headerView.frame=CGRectMake(0, 0, 955, 45);


  UILabel *fromLabel=[self returnLabel];
  fromLabel.frame=CGRectMake(400, 5, 200, 44);
  fromLabel.text=@"Open Time";
  [headerView addSubview:fromLabel];
  [fromLabel release];(in correct decrement of the reference count of an object that is not owned at this point by the caller)

 [self.headerView addSubview:fromLabel];
 [self.view addSubview:self.headerView];
 [self.headerView release];

}

-(UILabel *)returnLabel
{
UILabel *label= [[UILabel alloc] init] ;
label.textColor = [UIColor blackColor];
label.font = FONT_TITLE;
label.numberOfLines=1;
label.textAlignment=UITextAlignmentLeft;
label.lineBreakMode=UILineBreakModeWordWrap;
label.backgroundColor=[UIColor clearColor];

return label;

}

这是我的两种方法.
1 .-(无效)returnHeaderView.
2 .-(UILabel *)returnLabel.

-returnLabel返回标签,方法返回的UILabel对象的引用传递给returnHeaderView方法的fromLabel UILabel对象.
然后我从Label对象中释放.

但它给出了记忆警告(
正确减少调用者此时不拥有的对象的引用计数.

所以任何人都建议我这个代码有什么问题.
以及如何释放方法返回的对象.

谢谢.

-(void)returnHeaderView
{
  self.headerView=[[[UIView alloc]init] autorelease];
  headerView.frame=CGRectMake(0, 0, 955, 45);

  UILabel *fromLabel = [[self returnLabel] retain];
  fromLabel.frame    = CGRectMake(400, 5, 200, 44);
  fromLabel.text     = @"Open Time";
  [headerView addSubview:fromLabel];
  [self.headerView addSubview:fromLabel];
  [self.view addSubview:self.headerView];
  //[self.headerView release];
}

-(UILabel *)returnLabel
{
  UILabel *label= [[UILabel alloc] init] ;
  label.textColor = [UIColor blackColor];
  label.font = FONT_TITLE;
  label.numberOfLines=1;
  label.textAlignment=UITextAlignmentLeft;
  label.lineBreakMode=UILineBreakModeWordWrap;
  label.backgroundColor=[UIColor clearColor];
  return [label autorelease];
}