foreach (string file in Request.Files)
{
   HttpPostedFile hpf = Request.Files[file] as HttpPostedFile;
   if (hpf.ContentLength == 0)
      continue;
   string savedFileName = Path.Combine(
      AppDomain.CurrentDomain.BaseDirectory,Path.GetFileName(hpf.FileName));
   hpf.SaveAs(savedFileName);
}

我把它转换成VB.NET：

For Each file As String In Request.Files
    Dim hpf As HttpPostedFile = TryCast(Request.Files(file),HttpPostedFile)
    If hpf.ContentLength = 0 Then
        Continue For
    End If
    Dim savedFileName As String = Path.Combine(AppDomain.CurrentDomain.BaseDirectory,Path.GetFileName(hpf.FileName))
    hpf.SaveAs(savedFileName)
Next

但是我从编译器得到一个无效的转换异常：

Value of type 'System.Web.HttpPostedFileBase' cannot be converted to 'System.Web.HttpPostedFile'.

汉斯曼在2008-06-27发布了他的例子,我认为它在当时工作. MSDN没有任何类似的例子,所以给出了什么？