How can I set the content type during itemadding event

Question

I am trying to set the content type programmatically using an itemadding eventreceiver so that when the user adds a document to a library the content type is pre-selected. I have two content types: Project Document and Document. I determine through code which type to use and set the column values. My problem is that I can't get the content type to switch to Project Document. Here is my code:

   SPContentTypeId ctId = properties.Web.ParentWeb.ContentTypes["Project Document"].Id;
    properties.AfterProperties["Content Type ID"] = ctId;
    properties.AfterProperties["Content Type"] = properties.Web.ParentWeb.ContentTypes[ctId].Name;

    properties.AfterProperties["ProjectID"] = "example id";
    properties.AfterProperties["Title"] = "random document";
    properties.AfterProperties["ProjName"] = "My Project";
    base.ItemAdding(properties);

When the properties form opens up the default content type (Document) is showing. When I switch to Project Document the values I added are there.

So my question is: How do I get it to change to the Project Document content type before the properties box opens?

Answer 1

Try setting "ContentType" and "ContentTypeId":

properties.AfterProperties["ContentTypeID"] = ctId;
properties.AfterProperties["ContentType"] = properties.Web.ParentWeb.ContentTypes[ctId].Name;