SPFieldLookup.LookupWebId property

Gets or sets the ID of the Web site that contains the list that is the source of this field's value.

Namespace:  Microsoft.SharePoint
Assembly:  Microsoft.SharePoint (in Microsoft.SharePoint.dll)

Syntax

'Declaration
Public Property LookupWebId As Guid
    Get
    Set
'Usage
Dim instance As SPFieldLookup
Dim value As Guid

value = instance.LookupWebId

instance.LookupWebId = value
public Guid LookupWebId { get; set; }

Property value

Type: System.Guid
The value of the ID property for the Web site.

Exceptions

Exception Condition
NotSupportedException

The list that the field belongs to is an external list

SPException

Once set, the value of the property cannot be changed.

Remarks

You must have SPBasePermissions.Open permissions to set this property.

Examples

The following example is a console application that queries a list's collection of fields for lookup fields. For each lookup field that is found, the application prints the name of the field, the title of the list that the lookup field points to, the field in the target list that is the source of the lookup field's value, and the name of the Web site where the source list is located.

using System;
using Microsoft.SharePoint;

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            using (SPSite siteCollection = new SPSite("http://localhost"))
            {
                using (SPWeb site = siteCollection.OpenWeb())
                {
                    SPList list = site.Lists["Completed Orders"];

                    foreach (SPField item in list.Fields)
                    {
                        if (item is SPFieldLookup)
                        {
                            SPFieldLookup field = (SPFieldLookup)item;

                            if (!String.IsNullOrEmpty(field.LookupList) && !String.IsNullOrEmpty(field.LookupField))
                            {
                                // Is this the primary or secondary field for a list relationship?
                                string strRelationship = field.IsRelationship ? "Primary":"Secondary";

                                // Print the display name of the field.
                                Console.WriteLine("\nField: {0} ({1} Field)", field.Title, strRelationship);

                                // Is this a secondary field in a list relationship?
                                if (field.IsDependentLookup)
                                {
                                    SPField primaryField = list.Fields[new Guid(field.PrimaryFieldId)];
                                    Console.WriteLine("Primary Field: {0}", primaryField.Title);
                                }

                                // Get the site where the target list is located.
                                using (SPWeb targetSite = siteCollection.AllWebs[field.LookupWebId])
                                {
                                    // Get the name of the list where this field gets information.
                                    SPList targetList = targetSite.Lists[new Guid(field.LookupList)];
                                    Console.WriteLine("Related list: {0}", targetList.Title);

                                    // Get the name of the field where this field gets information.
                                    SPField targetField = targetList.Fields.GetFieldByInternalName(field.LookupField);
                                    Console.WriteLine("Related field: {0}", targetField.Title);
                                }
                            }
                        }
                    }
                }
            }
            Console.Write("\nPress ENTER to continue...");
            Console.ReadLine();
        }
    }
}
Imports System
Imports Microsoft.SharePoint

Module ConsoleApp

    Sub Main()
        Using siteCollection As New SPSite("http://localhost")
            Using site As SPWeb = siteCollection.OpenWeb()
                Dim list As SPList = site.Lists("Pending Orders")

                For Each item As SPField In list.Fields
                    If TypeOf item Is SPFieldLookup Then
                        Dim field As SPFieldLookup = DirectCast(item, SPFieldLookup)

                        If Not String.IsNullOrEmpty(field.LookupList) AndAlso Not String.IsNullOrEmpty(field.LookupField) Then
                            ' Is this the primary or secondary field for a list relationship?
                            Dim strRelationship As String = If(field.IsRelationship, "Primary", "Secondary")

                            ' Print the display name of the field.
                            Console.WriteLine(vbLf & "Field: {0} ({1} Field)", field.Title, strRelationship)

                            ' Is this a secondary field in a list relationship?
                            If field.IsDependentLookup Then
                                Dim primaryField As SPField = list.Fields(New Guid(field.PrimaryFieldId))
                                Console.WriteLine("Primary Field: {0}", primaryField.Title)
                            End If

                            ' Get the site where the target list is located.
                            Using targetSite As SPWeb = siteCollection.AllWebs(field.LookupWebId)
                                ' Get the name of the list where this field gets information.
                                Dim targetList As SPList = targetSite.Lists(New Guid(field.LookupList))
                                Console.WriteLine("Related list: {0}", targetList.Title)

                                ' Get the name of the field where this field gets information.
                                Dim targetField As SPField = targetList.Fields.GetFieldByInternalName(field.LookupField)
                                Console.WriteLine("Related field: {0}", targetField.Title)
                            End Using
                        End If
                    End If
                Next
            End Using
        End Using
        Console.Write(vbLf & "Press ENTER to continue...")
        Console.ReadLine()
    End Sub
End Module

See also

Reference

SPFieldLookup class

SPFieldLookup members

Microsoft.SharePoint namespace

LookupList

LookupField