Guid.Empty Field
Microsoft Silverlight will reach end of support after October 2021. Learn more.
A read-only instance of the Guid class whose value is guaranteed to be all zeroes.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared ReadOnly Empty As Guid
public static readonly Guid Empty
Remarks
You can compare a GUID with the value of the Guid.Empty field to determine whether a GUID is non-zero. The following example uses the Equality operator to compare two GUID values with Guid.Empty to determine whether they consist exclusively of zeros.
Module Example
Public Sub Demo(outputBlock As System.Windows.Controls.TextBlock)
' Create a GUID and determine whether it consists of all zeros.
Dim guid1 As Guid = Guid.NewGuid
outputBlock.Text += guid1.ToString() + vbCrLf
outputBlock.Text += String.Format("Empty: {0}", guid1 = Guid.Empty) + vbCrLf
outputBlock.Text += vbCrLf
' Create a GUID with all zeros and compare it to Empty.
Dim bytes(15) As Byte
Dim guid2 As New Guid(bytes)
outputBlock.Text += guid2.ToString() + vbCrLf
outputBlock.Text += String.Format("Empty: {0}", guid2 = Guid.Empty) + vbCrLf
End Sub
End Module
' The example displays output like the following:
' 11c43ee8-b9d3-4e51-b73f-bd9dda66e29c
' Empty: False
'
' 00000000-0000-0000-0000-000000000000
' Empty: True
using System;
public class Example
{
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
// Create a GUID and determine whether it consists of all zeros.
Guid guid1 = Guid.NewGuid();
outputBlock.Text += guid1.ToString() + "\n";
outputBlock.Text += String.Format("Empty: {0}\n\n", guid1 == Guid.Empty);
// Create a GUID with all zeros and compare it to Empty.
Byte[] bytes = new Byte[16];
Guid guid2 = new Guid(bytes);
outputBlock.Text += guid2.ToString() + "\n";
outputBlock.Text += String.Format("Empty: {0}\n", guid2 == Guid.Empty);
}
}
// The example displays output like the following:
// 11c43ee8-b9d3-4e51-b73f-bd9dda66e29c
// Empty: False
//
// 00000000-0000-0000-0000-000000000000
// Empty: True
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0
XNA Framework
Supported in: Xbox 360, Windows Phone OS 7.0
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.