除了上次修改的文件之外，如何检查每个ListView组中的所有文件？ C＃

Question

How to check checkboxes of all files in each ListView Group except the Last Modified File?

I've programmatically created a list of 500 files in multi-column ListView1 in C#:

File Name , Author , Last Modified Date (Total 3 Columns)

Group 1: (All files with John as Author)
--------
File1.txt, John, 17-01-2019 8:09:21 PM
File4.jpg, John, 20-01-2019 5:04:21 PM
File6.docx, John,25-12-2014 3:02:40 AM

Group 2: (All files with Muller as Author)
--------
File2.txt, Muller, 13-07-2013 2:02:21 AM
File3.jpg, Muller, 10-04-2012 4:04:21 AM
File5.docx, Muller, 15-10-2016 8:04:40 PM
File7.png, Muller, 20-03-2019 4:15:20 PM
File8.xml, Muller, 10-06-2015 8:40:00 AM

Group 3:
...............
and the list goes on...

I want to programmatically check-up checkboxes of all files in each group except the Last Modified File. I tried for several hours with different codes with no luck.

Your help is really appreciated..

foreach (ListViewGroup grp in listFiles.Groups)
    {
      bool FirstItem = false;
        foreach (ListViewItem item in grp.Items)
        {
            if (!FirstItem)
            {
                item.Checked = false;
                FirstItem = true;
            }
            else
            {
                item.Checked = true;
            }
        }
    }

Answer 1

Keep two variables, last and curr, initially null. For each item, set curr = item, if curr's last modified date is later than prev's last modified date, or if last is null, set last = curr. At the end of this loop, last is the item which has the latest last modified date. Do another loop and check everything except last.

You could do this in one loop, but I'll leave it as an exercise.