Guid.ParseExact Method (String, String)


Converts the string representation of a GUID to the equivalent Guid structure, provided that the string is in the specified format.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

Public Shared Function ParseExact (
	input As String,
	format As String
) As Guid


Type: System.String

The GUID to convert.

Type: System.String

One of the following specifiers that indicates the exact format to use when interpreting input: "N", "D", "B", "P", or "X".

Return Value

Type: System.Guid

A structure that contains the value that was parsed.

Exception Condition

input or format is null.


input is not in the format specified by format.

The ParseExact method requires the string to convert to be exactly in the format specified by the format parameter, after leading and trailing white-space characters are removed. The following table shows the accepted format specifiers for the format parameter. "0" represents a digit; hyphens ("-"), braces ("{", "}"), and parentheses ("(", ")") appear as shown.


Format of the input parameter


32 digits:



32 digits separated by hyphens:



32 digits separated by hyphens, enclosed in braces:



32 digits separated by hyphens, enclosed in parentheses:



Four hexadecimal values enclosed in braces, where the fourth value is a subset of eight hexadecimal values that is also enclosed in braces:


The following example calls the ToString(String) method with each of the supported format specifiers to generate an array of strings that represent a single GUID. These are then passed to the ParseExact method, which successfully parses only the string that conforms to the "B" format specifier.

Module Example
   Public Sub Main()
      ' Define an array of all format specifiers.
      Dim formats() As String = { "N", "D", "B", "P", "X" }
      Dim guid As Guid = Guid.NewGuid()
      ' Create an array of valid Guid string representations.
      Dim stringGuids(formats.Length - 1) As String
      For ctr As Integer = 0 To formats.Length - 1
         stringGuids(ctr) = guid.ToString(formats(ctr))

      ' Parse the strings in the array using the "B" format specifier.
      For Each stringGuid In stringGuids
            Dim newGuid As Guid = Guid.ParseExact(stringGuid, "B")
            Console.WriteLine("Successfully parsed {0}", stringGuid)
         Catch e As ArgumentNullException
            Console.WriteLine("The string to be parsed is null.")
         Catch e As FormatException
            Console.WriteLine("Bad Format: {0}", stringGuid)
         End Try   
   End Sub
End Module
' The example displays the following output:
'    Bad Format: 3351d3f0006747089ff928b5179b2051
'    Bad Format: 3351d3f0-0067-4708-9ff9-28b5179b2051
'    Successfully parsed {3351d3f0-0067-4708-9ff9-28b5179b2051}
'    Bad Format: (3351d3f0-0067-4708-9ff9-28b5179b2051)
'    Bad Format: {0x3351d3f0,0x0067,0x4708,{0x9f,0xf9,0x28,0xb5,0x17,0x9b,0x20,0x51}}

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Available since 4.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1
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