Guid.Empty Field
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
A read-only instance of the Guid class whose value is guaranteed to be all zeroes.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
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
Windows Phone OS
Supported in: 8.1, 8.0, 7.1, 7.0
Platforms
Windows Phone