如何在使用MethodForm.Post ASP.NET MVC上载文件时获取表单元素的值?

<%using (Html.BeginForm("Upload", "Photos", new { id = Model.Gallery.GalleryID }, FormMethod.Post, new { @enctype = "multipart/form-data" }))
          {%>
        <p>
            <span class="bold block">Photo 1:</span>
            <input type="file" name="File1" class="block" />
            <span class="bold block">File Name:</span>
            <input type="text" class="txt-base width50" id="txtFile1" />
            <span class="bold block">Description</span>
            <input type="text" class="txt-base width80" id="txtCaption1" />

        </p>            
        <p>
            <input type="submit" class="btn-admin cursorPointer" value="Upload" />
        </p>
        <%}%>

我需要获取txtFile(I)和txtCaption(I)的值。。。

 for (int i = 0; i < Request.Files.Count ; i++)
            {
                var hpf = Request.Files[i];
                var strFileName = Request.Form["txtFile" + (i + 1)];
                var strCaption = Request.Form["txtCaption" + (i + 1)];
                ...
                ...

但是由于being方法是“FormMethod.Post”,我无法使用Request.Form[“txtFile1”]获取值;