IContentAsyncEtag Property

string Etag { get; }

ReadOnly Property Etag As String
	Get

property String^ Etag {
	String^ get ();
}

abstract Etag : string with get

Property Value

This property shall return different value if content changes. Typically you will return either file content cheksum or hash or counter which increases with every modification. Change ETag every time a file content is updated in WriteAsync(Stream, String, Int64, Int64) method, together with a modification date. Do NOT change ETag when locking/unlocking a file.

Return null to indicate that server doesn't support ETags. Note that many client applications, including Microsoft Office, require ETag for correct functioning.

More information about ETags could be found here: http://en.wikipedia.org/wiki/HTTP_ETag.

The code below is part of 'WebDAVServer.FileSystemStorage.AspNet' C# & VB samples provided with the SDK.

public string Etag
{
    get { return string.Format("{0}-{1}", Modified.ToBinary(), this.serialNumber); }
}

Public ReadOnly Property Etag As String Implements IContentAsync.Etag
    Get
        Return String.Format("{0}-{1}", Modified.ToBinary(), Me.serialNumber)
    End Get
End Property

Reference