When item added event receiver fires if we upload file using explorer?

Question

I have a document library in which I have attached two event receivers.

1. Item Added.
2. Item Updated.

My event receiver definition is:

<Receiver>
    <Name>ReceiverItemAdded</Name>
    <Type>ItemAdded</Type>
    <Assembly>XXX</Assembly>
    <Class>XXX</Class>
    <SequenceNumber>10000</SequenceNumber>
    <Synchronization>Synchronous</Synchronization>
</Receiver>

The event receivers simply copies the item and metadata to other document library.

The event receivers work fine if I upload the document from SharePoint. But the Item Added event receiver does not work if I upload multiple files using explorer. The destination file shows the 0 KB size, but the metadata is copied successfully.

The code which copies the file is as below:

// Copy File                            
SPFile newFile = destLibrary.RootFolder.Files.Add(addedItem.File.Name, addedItem.File.OpenBinary());
SPListItem newItem = newFile.Item;
newItem[FieldNames.ImagesId] = addedItem[SPBuiltInFieldId.ID];
newItem.Update();

It is must to solve the issue as users would use the explorer to upload the file. Where is the point that to be caught in the code which will trigger Item Added event receiver if file is uploaded using explorer.

Please help.

Answer 1

You problem is similar to the following issue : https://stackoverflow.com/questions/6528623/sharepoint-itemadded-and-spfile-openbinary-zero-bytes

So you can just try to add some delay before uploading the file. This is not a solution for your problem, but can be a workaround for your solution.

You can try following check in your code:

if (properties.ListItem.File.Length == 0)
             {

               System.Threading.Thread.Sleep(2000);

               //Since our item exists, run the GetItemById to instantiate a new  and updated SPListItem object 
               var spFile = properties.List.GetItemById(properties.ListItemId);

               //SharePoint places an Exclusive lock on the file while the data is being loaded into the file
               while (spFile.File.LockType != SPFile.SPLockType.None)
                     {
                       System.Threading.Thread.Sleep(2000);
                       spFile = properties.List.GetItemById(properties.ListItemId);

                       //We need to check if the file exists, otherwise it will loop forever if someone decides to cancel the upload
                       if (!spFile.File.Exists)
                        return;
                     }

                //If someone thought it was a good idea to actually load a 0 byte file, don't do anything else
                if (spFile.File.Length == 0)
                       return;

              }