Adding a Non-Static Class to a static List

Question

I have a Non Static class which contains a number of properties

private static List<FileClass> FileClassList = new List<FileClass>();
internal void AddFile(Alphaleonis.Win32.Filesystem.FileInfo finfo)
   {
       this.FileID = FileIDCounter;
       this.Name = finfo.Name;
       this.FullName = finfo.FullName;
       this.Attributes = GetFileAttributes(finfo);
       this.CreationTime = finfo.CreationTime;
       this.Extension = finfo.Extension;
       this.isReadOnly = finfo.IsReadOnly;
       this.LastAccessTime = finfo.LastAccessTime;
       this.LastWriteTime = finfo.LastWriteTime;
       this.Length = finfo.Length;

       Interlocked.Increment(ref FileIDCounter); // As a Static value this is shared amongst all the instances of the class
       // Interlocked.Increment is the Thread Safe way of saying FileIDCounter ++;

       FileClassList.Add(this);
       if (FileClassFileAdded != null) FileClassFileAdded(this);

   }

Although the Class is added FileClassList.Add(this); the final result is a FileClassList filled with whatever the last instance of the class contained and not the this.Properties values.

So, how do I add the current instance of the FileClass to the FileClassList so that the contents of the FileClassList contains the different instances of the FileClass.

Answer 1

Here is what your issue most likely is...

Having this:

  internal void AddFile(Alphaleonis.Win32.Filesystem.FileInfo finfo)

Somewhere you probably do:

 MyClassWhichAddsAFile cls = new MyClassWhichAddsAFile();
 cls.AddFile(fileInfo1);
 cls.AddFile(fileInfo2);
 cls.AddFile(fileInfo3);

While you need to do (under this design):

 MyClassWhichAddsAFile cls1 = new MyClassWhichAddsAFile();
 cls1.AddFile(fileInfo1);
 MyClassWhichAddsAFile cls2 = new MyClassWhichAddsAFile();
 cls2.AddFile(fileInfo2);
 ........

Again, I am not discussing your design here or how to do it right. I am telling you that your problem is probably comes out from this situation

Answer 2

I think you have your design slightly askew. I don't think that AddFile should be part of FileClassList rather. However in leiu of not having another place to hold it. I'd say do this:

   internal static void AddFile(Alphaleonis.Win32.Filesystem.FileInfo finfo, FileClass theClass)
   {
       theClass.FileID = FileIDCounter;
       theClass.Name = finfo.Name;
       theClass.FullName = finfo.FullName;
       theClass.Attributes = GetFileAttributes(finfo);
       theClass.CreationTime = finfo.CreationTime;
       theClass.Extension = finfo.Extension;
       theClass.isReadOnly = finfo.IsReadOnly;
       theClass.LastAccessTime = finfo.LastAccessTime;
       theClass.LastWriteTime = finfo.LastWriteTime;
       theClass.Length = finfo.Length;

       Interlocked.Increment(ref FileIDCounter); // As a Static value this is shared amongst all the instances of the class
       // Interlocked.Increment is the Thread Safe way of saying FileIDCounter ++;

       FileClassList.Add(theClass);
       if (FileClassFileAdded != null) FileClassFileAdded(theClass);

   }

A better approach would be to create a contrstuctor on FileClass that takes a FileInfo and fills these properties in and call it like this:

var someFileClass = new FileClass(theFileInfo);
FileClass.AddFile(someClassFile);

and AddFile would be:

   internal static void AddFile(Alphaleonis.Win32.Filesystem.FileInfo finfo, FileClass theClass)
   {

       Interlocked.Increment(ref FileIDCounter); // As a Static value this is shared amongst all the instances of the class
       // Interlocked.Increment is the Thread Safe way of saying FileIDCounter ++;

       FileClassList.Add(theClass);
       if (FileClassFileAdded != null) FileClassFileAdded(theClass);

   }

even then I think the AddFile should be a method on the the caller not the callee!