如何将标签变成滚动标签？

Question

We have a view that we want to have "grow" to be larger after it is tapped. If it is too large to fit on the screen that area should be in a UIScrollView. The UIScrollView does not scroll. My guess is that I have my constraints wrong. I'm not sure what debug tricks I should use to provide more information here for help.

The main view has an image that takes up about 2/3 of the screen, a view at the bottom, and then a view that has its bottom aligned with the top of the view at the bottom, so that it overlays the bottom area of the image (alpha transparency set at .5). This view has a scrollview, and that scroll view has a label. That label shows two lines of text. That is all laid out fine (and we don't want the scroll view to scroll at this point. I didnt code to prevent that; its just not scrolling).

There is a tap gesture to that last view. When its tapped, the text label is changed from two lines to 0 lines. There's a height constraint using >= on the label. There is a height constraint so that the view does not expand up into the navigation bar. The views all grow to the right size. Now if that text is so large that we are running into those limiting height constraints, we want that text to scroll.

Why won't the text scroll? Scrolling is enabled. I dont know if I need to do something with the content size of the UIScrollView since the number of lines has changed.

Answer 1

Without seeing your code, I can only speculate. But a common omission is failing to set the contentSize property of your UIScrollView after its content have changed or moved.