Differences between contentsize, contentoffset, and contentinset

Contentsize is an attribute in scrollview. It represents the display area in scrollview. If there is a scrollview, its frame is (320,480, 320,960), and its contentsize is ). that is to say, the size of the entire scrollview is (320,960). You need to slide scrollview up and down to view the content after (320,480.

ContentoffsetIt is the offset of the vertex in the current display area of scrollview relative to the frame vertex. For example, if you pull to the bottom of the last example, contentoffset is (0,480), that is, y offset is 480.

Contentinset is the relationship between contentview. Frame. Origin and scrollview. Frame. Origin in scrollview. For example, if the frame of contentview is (320,480,), contentinset is (0, 30 ),