下面的代码运行完美，但是我需要新字段位于第 5 位，而不是表单的末尾。
知道怎么做吗？
private void UpdateDossierContentType(SPWeb parentWeb)
{
SPList productList = parentWeb.Site.RootWeb.Lists["Product"];
SPFieldLookup lookup = CreateLookupField("ProductNameLookup", "CustomGroup",
false, false, parentWeb.Site.RootWeb,
parentWeb.Site.RootWeb.Lists["Product"],
productList.Fields["Product Name"].InternalName);
LinkFieldToContentType(parentWeb.Site.RootWeb, "Dossier", (SPField)lookup);
//SPContentType dossierCT = productList.ContentTypes["Dossier"];
//dossierCT.DeleteFieldRefFromContentType(parentWeb.Fields["Product"]);
//dossierCT.Update();
}
public static void LinkFieldToContentType(SPWeb web, string contentType, SPField field)
{
SPContentType ct = web.ContentTypes[contentType];
ct.FieldLinks.Add(new SPFieldLink(field));
ct.Update(true);
}
public static SPFieldLookup CreateLookupField(string fieldName, string group, bool required, bool allowMultipleValues, SPWeb w, SPList lookupList, string lookupField)
{
w.Fields.AddLookup(fieldName, lookupList.ID, lookupList.ParentWeb.Site.RootWeb.ID, required);
SPFieldLookup lookup = (SPFieldLookup)w.Fields[fieldName];
lookup.AllowMultipleValues = allowMultipleValues;
lookup.LookupField = lookupField;
lookup.Group = group;
lookup.Update(true);
return lookup;
}