Guid.Empty Campo

Definição

Namespace:

System

Assembly:

System.Runtime.dll

Origem:

Guid.cs

Uma instância somente leitura da estrutura Guid cujo valor é zero.

public: static initonly Guid Empty;

public static readonly Guid Empty;

 staticval mutable Empty : Guid

Public Shared ReadOnly Empty As Guid 

Valor do campo

Guid

Comentários

Você pode comparar um GUID com o valor do Guid.Empty campo para determinar se um GUID não é zero. O exemplo a seguir usa o Equality operador para comparar dois valores guid com Guid.Empty para determinar se eles consistem exclusivamente em zeros.

// Create a GUID and determine whether it consists of all zeros.
Guid guid1 = Guid.NewGuid();
Console.WriteLine(guid1);
Console.WriteLine($"Empty: {guid1 == Guid.Empty}\n");

// Create a GUID with all zeros and compare it to Empty.
var bytes = new Byte[16];
var guid2 = new Guid(bytes);
Console.WriteLine(guid2);
Console.WriteLine($"Empty: {guid2 == Guid.Empty}");

// The example displays output like the following:
//       11c43ee8-b9d3-4e51-b73f-bd9dda66e29c
//       Empty: False
//
//       00000000-0000-0000-0000-000000000000
//       Empty: True

open System

// Create a GUID and determine whether it consists of all zeros.
let guid1 = Guid.NewGuid()
printfn $"{guid1}"
printfn $"Empty: {guid1 = Guid.Empty}\n"

// Create a GUID with all zeros and compare it to Empty.
let bytes = Array.zeroCreate<byte> 16
let guid2 = Guid bytes
printfn $"{guid2}"
printfn $"Empty: {guid2 = Guid.Empty}"

// The example displays output like the following:
//       11c43ee8-b9d3-4e51-b73f-bd9dda66e29c
//       Empty: False
//
//       00000000-0000-0000-0000-000000000000
//       Empty: True

Module Example
   Public Sub Main()
      ' Create a GUID and determine whether it consists of all zeros.
      Dim guid1 As Guid = Guid.NewGuid
      Console.WriteLine(guid1)
      Console.WriteLine("Empty: {0}", guid1 = Guid.Empty)
      Console.WriteLine()
      
      ' Create a GUID with all zeros and compare it to Empty.
      Dim bytes(15) As Byte
      Dim guid2 As New Guid(bytes)
      Console.WriteLine(guid2)
      Console.WriteLine("Empty: {0}", guid2 = Guid.Empty)
   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