SPFieldLookup.LookupList property
Gets or sets the string representation of the GUID that identifies 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 LookupList As String
Get
Set
'Usage
Dim instance As SPFieldLookup
Dim value As String
value = instance.LookupList
instance.LookupList = value
public string LookupList { get; set; }
Property value
Type: System.String
The string representation of the GUID that identifies the list that is the source of information for the field. An empty string is returned if the field does not point to a list.
Exceptions
| Exception | Condition |
|---|---|
| SPException | The property has already been set. You cannot change the lookup list after the LookupList property is set. |
Remarks
This property returns the string representation of the source list's ID property. The LookupList property is set automatically when you create an SPFieldLookup object by calling the AddLookup or AddDependentLookup method of the SPFieldCollection object that represents the field collection for the list where you want to add the lookup column.
Important
Once a lookup column is established, the target list cannot be changed.
Examples
The following example is a console application that enumerates the fields associated with a list, looking for fields of type SPFieldLookup. When it finds a field of that type, the application uses the value of the LookupList property to get a reference to the list that the lookup field points to and then the value of the LookupField property to get the field in the target list that the lookup field points to.
using System;
using Microsoft.SharePoint;
namespace ConsoleApp
{
class Program
{
static void Main(string[] args)
{
using (SPSite siteCollection = new SPSite("https://localhost"))
{
using (SPWeb site = siteCollection.OpenWeb())
{
SPList list = site.Lists["Pending 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("https://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
Microsoft.SharePoint namespace