using object to load dropdown error is "It must be either an IListSource, IEnumerable, or IDataSource."

            project objProj = new project();
            objProj.LoadAll();

            DropDownList ddTemp = new DropDownList();
            
            ddTemp.DataSource = objProj;
            ddTemp.DataValueField = "idProject";
            ddTemp.DataTextField = "projectName";
            ddTemp.DataBind();

error is "It must be either an IListSource, IEnumerable, or IDataSource".