SPFieldLookup.IsDependentLookup property
Gets a Boolean value that indicates whether the field is a secondary lookup field that depends on a primary field for its relationship with the lookup list.
Namespace: Microsoft.SharePoint
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
Syntax
'Declaration
Public ReadOnly Property IsDependentLookup As Boolean
Get
'Usage
Dim instance As SPFieldLookup
Dim value As Boolean
value = instance.IsDependentLookup
public bool IsDependentLookup { get; }
Property value
Type: System.Boolean
true if the lookup field is a dependent lookup field; otherwise, false.
Remarks
When this property returns true, the current SPFieldLookup object represents a secondary column in a multiple column lookup. In this case, the object's PrimaryFieldId property has a value that is the string representation of a GUID that identifies the object that represents the primary column on which the secondary column depends for its relationship to the lookup list.
Examples
The following example is a console application that examines the collection of fields associated with a list, looking for SPFieldLookup objects. When it finds one, code in the application determines whether the object represents a primary or secondary column. If the object represents a secondary column, the code uses the value returned by the PrimaryFieldId property to get the display name of the primary column.
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["Complete 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);
}
}
}
}
}
}
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
End If
End If
Next
End Using
End Using
Console.Write(vbLf & "Press ENTER to continue...")
Console.ReadLine()
End Sub
End Module