Sorting a List by creation date C#

Question

Using this example off MSDN:

using System.Collections.Generic;  
using System.IO;  

namespace CollectionTest  
{  
    public class ListSort  
    {  
        static void Main(string[] args)  
        {  
            List<FileInfo> files = new List<FileInfo>();  
            files.Add(new FileInfo("d(1)"));  
            files.Add(new FileInfo("d"));              
            files.Add(new FileInfo("d(2)"));  

            files.Sort(new CompareFileInfoEntries());  
        }           

    }  

    public class CompareFileInfoEntries : IComparer<FileInfo> 
    {  
        public int Compare(FileInfo f1, FileInfo f2)  
        {  
            return (string.Compare(f1.Name, f2.Name));  
        }  
    }  

}

How would I compare the date of creation.

F1 has a property "creation" date which is a FileSystemInfo.Datetime, yet when I try this:

  public class CompareFileInfoEntries : IComparer<FileInfo>
  {
      public int Compare(FileInfo f1, FileInfo f2)
      {

          return (DateTime.Compare(DateTime.Parse(f1.CreationTime), f2.CreationTime));
      }
  }  
}

I get overload method matches for String. compare(string,string) Note: Ive used two methods in the above script to attempt returning the creation time. Neither have worked - they would both be the same in my actual script.

CLosest I can get is:

return (DateTime.Compare(DateTime.Parse(f1.CreationTime.ToString()), DateTime.Parse(f2.CreationTime.ToString() )));

score 25 · Accepted Answer · answered Jan 25 '12 at 11:00

25

Description

You can simple use LINQ (namespace System.Linq) for that.

Language Integrated Query (LINQ, pronounced "link") is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages

Sample

List<FileInfo> orderedList = files.OrderBy(x => x.CreationTime).ToList();

More Information

answered Jan 25 '12 at 11:00

dknaack

60,192
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Damn. Forgot I could use LINQ. One downside of using intellisense when you haven't called the LINQ namespace! Thanks – JustAnotherDeveloper Jan 25 '12 at 11:06

score 4 · Answer 2 · answered Jan 25 '12 at 11:00

4

Umm what about using linq

files.OrderBy(f=>f.CreationTime)

answered Jan 25 '12 at 11:00

undefined

33,537
22
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198

score 0 · Answer 3 · edited Apr 25 '13 at 13:12

Dim filePath as string = "c:\\"

This command get directory file list ordered by ASC

Dim orderedFiles = New System.IO.DirectoryInfo(filePath).GetFiles("*.xml")
                                                        .OrderBy(Function(x) x.CreationTime)

This command get directory file list ordered by DESC

Dim orderedFiles = New System.IO.DirectoryInfo(filePath).GetFiles("*.xml")
                                                        .OrderByDescending(Function(x) x.CreationTime)

score -2 · Answer 4 · answered Jan 25 '12 at 11:08

-2

Try this:

public class CompareFileInfoEntries : IComparer<FileInfo> 
    { 
        public int Compare(FileInfo f1, FileInfo f2) 
        {
            return (string.Compare(f1.CreationTime.ToString(), f2.CreationTime.ToString())); 
        } 
    }

answered Jan 25 '12 at 11:08

Tapas Mahata

343
6
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That is almost guaranteed to fail to work properly, though it might *purely accidentally* work on some Cultures. – Andrew Barber Jan 25 '12 at 16:26
@Barber - Even if the cultures changes, both of the fileinfo creation time will be changed against that culture and if both of them are changed accordingly then it should work fine.. I am confused !!! – Tapas Mahata Jan 27 '12 at 05:14
In en-us, the date would outpit like this: *1/28/2012 12:28:30pm* compared to *5/15/1972 5:34:10pm* The sorting would be *wrong*. You are converting to a string which does *not* sort the same way as a date. – Andrew Barber Jan 27 '12 at 05:30

Sorting a List by creation date C#

4 Answers4

Description

Sample

More Information

Linked