UITableView的可重用池如何查看内容

Question

I was trying to deep dive into how the UITableView works internally. I've already read multiple posts regarding that like,

https://www.mikeash.com/pyblog/friday-qa-2013-02-22-lets-build-uitableview.html

I want to know if there is any way we can look into the content of the reusable pool , ie how many and what all UITableViewCell types are available inside it at a moment.

I already know that we'll have the cells as per the screen size and the cell height . But I'm trying to figure out what happens if the tableView accepts different types of cells at different indexPaths .

Answer 1

Well, you can dig down into the objects in debug...

I set a breakpoint in didSelectRowAt and looked into the Variables View pane:

I had one row (index path [0,3] that used TestCellB and 90 rows that used TestCell , and the table was scrolled to row 21 (so row [0,3] was well off-screen.

As you can see, there is an internal Dictionary named _reusableTableCells which, in my example, currently contains 1 TestCellB and 2 TestCell s.

---

EDIT

I just gave this a try - might give you some additional info:

    var reusableCells = tableView.value(forKey: "_reusableTableCells")
    print(reusableCells)

Output:

Optional({
    TestCellB =     (
        "<TranslateTest.TestCellB: 0x7f87b206aa00; baseClass = UITableViewCell; frame = (0 1612; 414 37); clipsToBounds = YES; hidden = YES; autoresize = W; layer = <CALayer: 0x600003a66380>>"
    );
    TestCellC =     (
        "<TranslateTest.TestCellC: 0x7f87b2894800; baseClass = UITableViewCell; frame = (0 205; 414 93); clipsToBounds = YES; hidden = YES; autoresize = W; layer = <CALayer: 0x600003a586e0>>",
        "<TranslateTest.TestCellC: 0x7f87b3000e00; baseClass = UITableViewCell; frame = (0 298; 414 93); clipsToBounds = YES; hidden = YES; autoresize = W; layer = <CALayer: 0x600003a5fe40>>"
    );
})