Since 1.11 it is possible to obtain extended data about the dragged files. It is possible to work with data through the IDataObject instance. To turn this feature on, you should set the Chromium switch "--enable-com-in-drag-drop" to enable COM object transfer.


The following sample code demonstrates how to handle OnDragEnterEvent and work with the bound IDataObject instance:

C#

private void OnDragEnterEvent(object sender, DragDropEventArgs e)
{
    string[] filenames = null;
    //Check if the source COM object present
    if (e.DataObject != null)
    {
        //Create System.Windows.DataObject for source COM IDataObject
        DataObject dataObject = new DataObject(e.DataObject);

        //Create Outlook wrapper
        OutlookDataObject dataObject = new OutlookDataObject(dataObject);

        //Get needed data
        filenames = (string[])dataObject.GetData("FileGroupDescriptorW");
    }
}

VB.NET

Private Sub OnDragEnterEvent(ByVal sender As Object, ByVal e As DragDropEventArgs)
    Dim filenames As String() = Nothing
    'Check if the source COM object present
    If e.DataObject IsNot Nothing Then

        'Create System.Windows.DataObject for source COM IDataObject
        Dim dataObject As DataObject = New DataObject(e.DataObject)

        'Create Outlook wrapper
        Dim dataObject As OutlookDataObject = New OutlookDataObject(dataObject)

        'Get needed data
        filenames = CType(dataObject.GetData("FileGroupDescriptorW"), String())
    End If
End Sub


Note: The IDataObject instance exists only in the scope of the DragEnterEvent handler. For the DropEvent and  DragExitEvent the e.DataObject property is expected to return null.