when I set rcl_top , why the height and width changed ?

[kaich]

I write code as below :

self.ivIcon=[[UIImageView alloc] initWithFrame:CGRectMake(20, 20, 80, 80)];
[self.view addSubview:self.ivIcon];
self.lblTitle=[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 200, 12)];
[self.view addSubview:self.lblTitle];
RCLAlignment(self.lblTitle)=@{
                              rcl_top: self.ivIcon.rcl_frameSignal.top,
                              };

I get the self.lblTitle frame = (0 20; 60 18). I don't know why the Height and Width changed. Could you tell me the reason. I am newer to ReactiveCocoa and The Framework. I try to debug find the reason. But I find It's so hard to find a useful information about it .
And what's the difference between RCLAlignment and RCLFrame. I can't understand it.
Hope your anwer, thanks

[jspahrsummers]

I don't know why the Height and Width changed.

Any components that are unspecified with RCLAlignment or RCLFrame will use the view's intrinsicContentSize.

And what's the difference between RCLAlignment and RCLFrame.

The former corresponds to -[UIView alignmentRectForFrame:], and the latter corresponds to UIView.frame.