如何从FieldLookupValue Sharepoint 2013 CSOM中检索关联的列表名称

Question

I need to retrieve some information from a FieldLookupValue using CSOM SharePoint2013 library. Specifically, I have a SPList and I need to populate a Field which type is Lookup. Is there a way to know the name of associated list? I know for sure that this information is contained in the FieldLookupvalue: if I create an instance of it using LookupID of associated Item SharePoint automatically associates the lists. Infact this code works well:

        switch (field.TypeAsString)
        {
            case "Lookup":
                int id = Convert.ToInt32(info);
                FieldLookupValue lv = new FieldLookupValue() { LookupId = id };
                newItem[field.InternalName] = lv;
                break; 
            default:
                // do nothing
                break;
        }

Answer 1

FieldLookupValue class does not expose any properties for getting associated list, but you could retrieve the associated list from a Lookup field

The following example demonstrates how to retrieve associated List for Predecessors field from Tasks list:

using (var ctx = new ClientContext(webUri))
{
     var list = ctx.Web.Lists.GetByTitle("Tasks");
     var field = list.Fields.GetByInternalNameOrTitle("Predecessors");
     var lookupField = ctx.CastTo<FieldLookup>(field);
     ctx.Load(lookupField);
     ctx.ExecuteQuery();
     var lookupListId = new Guid(lookupField.LookupList); //returns associated list id
     //Retrieve associated List
     var lookupList = ctx.Web.Lists.GetById(lookupListId);
     ctx.Load(lookupList);
     ctx.ExecuteQuery();
}