问题
I'm trying to move storyboard items in my viewcontroller layout, but the when ran in the simulator, they won't budge. It seems that they are sticking to the orange dotted lines above where I placed them. What are those orange lines and why can't I move my items?
Here's what it looks like in the simulator:
回答1:
Those orange dotted lines show that the frames of the views don't match their constraints.
In this example, I placed a label, pinned it's leading and top space, then moved the label. Moving the label changes it's frame, so now the frame doesn't agree with the leading and top space constraints.
Note that next to View Controller Scene, there's now a yellow warning icon. Clicking on this icon brings up this:
Clicking on the yellow triangle icon gives a few options for fixing the problem. In this case, since I wanted to move the label to a new position, I choose Update Constraints to make the constraints match the new frame.
来源：https://stackoverflow.com/questions/19085869/ios7-storyboard-items-wont-move