尝试在编辑时使带有UITextField的自定义UITableViewCell成为FirstResponder

Question

I have a UITableViewController with custom UITableViewCell s that contain a UITextField . When switching the table view into edit mode, I add a new cell to the bottom of the table and would like to make this cell becomeFirstResponder . My tableView:cellForRowAtIndexPath: method checks for this bottom cell, so I just added the line:

[cell.theTextField becomeFirstResponder];

Which I believed should work. However, when the table view is first displayed, it does not seem to be working. BUT if I select the cell (making it the first responder), then go out of edit mode (causing a resignFirstResponder within my code), I can then go back into edit mode and magically it becomes the first responder as I would expect!

Note that even if I end editing mode with a different cell selected (they all have text fields) and go out of edit mode, then back in, it still works, as long as at some point I had made the last cell becomeFirstResponder (by selecting it).

So, my guess is that when it first becomes the first responder, there is something getting set either in the table view or some place else that wasn't originally set, and from then on it makes this work.

Anyone have any ideas as to what may be going on here?

Answer 1

The first becomeFirstResponder call fails because the cell doesn't have a superview yet. The table view adds the cell as its subview after you return it from tableView:cellForRowAtIndexPath: . I suggest you make this call somewhere else. If you already have a custom UITableViewCell subclass, you could implement didMoveToWindow: and call [self becomeFirstResponder] there.