Tableview scrolling bounces back and hides the bot

问题:

I have a view that is shown under a navigation controller. The view contains one subview at the top portion and a table view at the bottom. The table might have rows that extend beyond the visible height based on data. When I have rows that are below the last visible row, if I scroll the view up, it bounces back, it does not stay there. Is there a way to make it stay? I tried making the parent view a scroll view and that did not help. My view is from a XIB.

回答1:

Sounds like the size of your UITableView is slightly larger than the area available on the iPhone screen. This might be because the view didn't take into account the size of hte navigation bar. As a test, go into Interface Builder and make the UITableView much smaller, say half the size, so you can clearly see the top and bottom. See if you still have the same bouncing.

If the sizes are correct, UITableView does not need a UIScrollView to function as expected. In fact, there would be few reasons, that I can think of right now (other than horizontal scroll ones), that you'd want a UITableView inside a UIScrollView.

回答2:

In your top level View Controller, in the "Simulated Metrics"-settings, set Top Bar and/or Bottom Bar (depending on what's displayed in your View Controller) to "opaque". Then resize the Table View to fit beween the Navigation Bar and the Tool Bar/Tab Bar. Finally, add two constraints:

1. Top Space to Top Layout Guide
2. Bottom Space to Bottom Layout Guide

Worked very well for me, regardless of orientation.

回答3:

If you are not using Storyboard, you could try the following (swift) code:

tableView.contentInset = UIEdgeInsetsMake( (self.navigationController!.navigationBar.frame.origin.y + self.navigationController!.navigationBar.frame.size.height), 0, 0, 0)

self.view.addSubview(tableView)

If you have a toolbar or (if you are using a TabBarController), you'll need to adjust the bottom too:

tableView.contentInset = UIEdgeInsetsMake( (self.navigationController!.navigationBar.frame.origin.y + self.navigationController!.navigationBar.frame.size.height), 0, 0, 0)

self.view.addSubview(tableView)

Please note that this is a simple and 'rough' code. You can make it prettier if needed :)