Convert VB to C#

We have this old code from an ASP website that we are moving over to ASP.NET C# - we are trying to make minimal changes to the old pages since it wasn't part of the contract but we need to swap this out to C# since all of the new stuff is in it.   I have part of it but not the loop piece.

Old code

 For a = 1 to Request.Form("propertyid").Count
strSQL = "Insert into property_assign (assigned_to, propertyid) VALUES ("
strSQL = strSQL & "'" & Request.Form("assigned_to") & "',"
strSQL = strSQL & "'" & Request.Form("propertyid")(a) & "')"

The start of my new code:

foreach (var Properties in Request("propertyid")) { 
            sql2 = "Insert into property_assign (assigned_to, propertyid) VALUES (@0, @1)";
            db.Execute(sql2, Request.Form("username"), Properties.propertyid);

I get Non-invocable member 'WebPageRenderingBase.Request' cannot be used like a method.