CODEWITHSUNDEEP
c#.net-2.0.net
JL.
JL.

Reputation: 81262

How to sort an array of FileInfo[]

I have the following code

DirectoryInfo taskDirectory = new DirectoryInfo(this.taskDirectoryPath);
FileInfo[] taskFiles = taskDirectory.GetFiles("*" + blah + "*.xml");

I would like to sort the list by filename.

How is this done, as quickly and easily as possible using .net v2.

Upvotes: 21

Views: 38566

Answers (4)

RV.
RV.

Reputation: 2842

    public class FileComparer : IComparer
        {
            public enum CompareBy
            {
                Name /* a-z */,
                LastWriteTime /* oldest to newest */,
                CreationTime  /* oldest to newest */,
                LastAccessTime /* oldest to newest */,
                FileSize /* smallest first */,

            }
            // default comparison
            int _CompareBy = (int)CompareBy.Name;
            public FileComparer()
            {
            }

            public FileComparer(CompareBy compareBy)
            {
                _CompareBy = (int)compareBy;
            }
            int IComparer.Compare( object x, object y )
            {
                int output = 0;
                DirectoryInfo file1 = new DirectoryInfo(x.ToString());
                DirectoryInfo file2 = new DirectoryInfo(y.ToString());
                switch(_CompareBy)
                {
                    case (int)CompareBy.LastWriteTime:
                        output = DateTime.Compare(file1.LastWriteTime, file2.LastWriteTime);
                        break;
                    case (int)CompareBy.CreationTime:
                        output = DateTime.Compare(file1.CreationTime, file2.CreationTime);
                        break;
                    case (int)CompareBy.LastAccessTime:
                        output = DateTime.Compare(file1.LastAccessTime, file2.LastAccessTime);
                        break;
    //              case (int)CompareBy.FileSize:
    //                  output = Convert.ToInt32(file1.Length - file2.Length);
    //                  break;
                    case (int)CompareBy.Name:
                    default:
                        output = (new CaseInsensitiveComparer()).Compare( file1.Name, file2.Name );
                        break;
                }
                return output;
            }
        }

///////////////////////////////////
ArrayList list=new ArrayList();         
            string folder = @"D:\DVRData\ICICI\Transaction\21-Dec-08\08_51_23_2231";
            string[] files = Directory.GetFiles(folder);            
            IComparer comp = new FileComparer(FileComparer.CompareBy.CreationTime);
            Array.Sort(files, comp);
            foreach(string file in files)
            {
                list.Add(file);
            }

Upvotes: 1

Marc Gravell
Marc Gravell

Reputation: 1062502

Array.Sort(taskFiles, delegate (FileInfo x, FileInfo y) {
    return string.Compare(x.Name,y.Name);
});

Upvotes: 9

Jon Skeet
Jon Skeet

Reputation: 1499770

Call Array.Sort, passing in a comparison delegate:

Array.Sort(taskFiles, delegate(FileInfo f1, FileInfo f2) {
    return f1.Name.CompareTo(f2.Name);
});

In C# 3 this becomes slightly simpler:

Array.Sort(taskFiles, (f1, f2) => f1.Name.CompareTo(f2.Name));

Or you can use a StringComparer if you want to use a case-insensitive sort order:

Array.Sort(taskFiles,
           (x, y) => StringComparer.OrdinalIgnoreCase.Compare(x.Name, y.Name));

(or use string.Compare(x.Name, y.Name, true), or any of the many other ways of comparing strings :)

Upvotes: 41

Thomas Levesque
Thomas Levesque

Reputation: 292345

Comparison<FileInfo> comparison = new Comparison<FileInfo>(delegate(FileInfo a, FileInfo b)
{
    return String.Compare(a.Name, b.Name);
});

Array.Sort(taskFiles, comparison);

But anyway I think the result of GetFiles is already sorted by name...

Upvotes: 0

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