Sharepoint自定义上载域和附件?

我开发了一个自定义的sharepoint字段,它将文件上载到特定的文档库中,并在将其保存为该字段的值后存储该文件的url。

如何避免将文件保存为附件?

谢谢您

编辑: 代码如下:

public override void UpdateFieldValueInItem()
        {

            string name="";

            if(fileUploader.PostedFile.FileName!="")
            {
            //method to store the posted file in a certain library
            string x= UploadFile(this.Web, fileUploader.PostedFile.FileName,fileUploader.FileName,out name);

            //Stores The URL and the name of the file
            SPFieldUrlValue urlValue = new SPFieldUrlValue() { 
                Description=name,
                Url=x
            };

            this.Value = urlValue;
            this.ItemFieldValue = urlValue;
            }
}

UploadFile方法

string UploadFile(SPWeb web,string path,string fileName,out string name)
        {
            UploadField uf = (UploadField)base.Field;



            SPList docsList = web.Lists[uf.StoreList];
            SPFolder folder = web.GetFolder(docsList.RootFolder.UniqueId);
            byte[] contents = File.ReadAllBytes(path);


            SPFile file= folder.Files.Add(folder.Url + "/" + fileName, contents);
            //folder.Update();
            SPListItem item = docsList.Items[file.UniqueId];

            name = item["Name"].ToString();
            return getItemURL(item);

        }