IPAddress.Parse Method (String)

 

Converts an IP address string to an IPAddress instance.

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

Public Shared Function Parse (
	ipString As String
) As IPAddress

Parameters

ipString
Type: System.String

A string that contains an IP address in dotted-quad notation for IPv4 and in colon-hexadecimal notation for IPv6.

Return Value

Type: System.Net.IPAddress

An IPAddress instance.

Exception Condition
ArgumentNullException

ipString is null.

FormatException

ipString is not a valid IP address.

The static Parse method creates an IPAddress instance from an IP address expressed in dotted-quad notation for IPv4 and in colon-hexadecimal notation for IPv6.

The number of parts (each part is separated by a period) in ipString determines how the IP address is constructed. A one part address is stored directly in the network address. A two part address, convenient for specifying a class A address, puts the leading part in the first byte and the trailing part in the right-most three bytes of the network address. A three part address, convenient for specifying a class B address, puts the first part in the first byte, the second part in the second byte, and the final part in the right-most two bytes of the network address. For example:

Number of parts and example ipString

IPv4 address for IPAddress

1 -- "65536"

0.0.255.255

2 -- "20.2"

20.0.0.2

2 -- "20.65535"

20.0.255.255

3 -- "128.1.2"

128.1.0.2

The following code converts a string that contains an IP address, in dotted-quad notation for IPv4 or in colon-hexadecimal notation for IPv6, into an instance of the IPAddress class. Then it uses the overloaded ToString method to display the address in standard notation.

Imports System
Imports System.Net



Class ParseAddress

   'Entry point which delegates to C-style main Private Function
   Public Overloads Shared Sub Main()
      Main(System.Environment.GetCommandLineArgs())
   End Sub


   Overloads Private Shared Sub Main(args() As String)
      Dim IPaddress As String

      If args.Length = 1 Then
         Console.WriteLine("Please enter an IP address.")
         Console.WriteLine("Usage:   >cs_parse any IPv4 or IPv6 address.")
         Console.WriteLine("Example: >cs_parse 127.0.0.1")
         Console.WriteLine("Example: >cs_parse 0:0:0:0:0:0:0:1")
         Return
      Else
         IPaddress = args(1)
      End If 
      ' Get the list of the IPv6 addresses associated with the requested host.
      parse(IPaddress)
   End Sub 'Main


   ' This method calls the IPAddress.Parse method to check the ipAddress 
   ' input string. If the ipAddress argument represents a syntatical correct IPv4 or
   ' IPv6 address, the method displays the Parse output into quad-notation or
   ' colon-hexadecimal notation, respectively. Otherwise, it displays an 
   ' error message.
   Private Shared Sub parse(ipAddr As String)
      Try
         ' Create an instance of IPAddress for the specified address string (in 
         ' dotted-quad, or colon-hexadecimal notation).
         Dim address As IPAddress = IPAddress.Parse(ipAddr)

         ' Display the address in standard notation.
         Console.WriteLine(("Parsing your input string: " + """" + ipAddr + """" + " produces this address (shown in its standard notation): " + address.ToString()))

      Catch e As ArgumentNullException
         Console.WriteLine("ArgumentNullException caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))

      Catch e As FormatException
         Console.WriteLine("FormatException caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))

      Catch e As Exception
         Console.WriteLine("Exception caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))
      End Try
   End Sub 'parse 
End Class 'ParseAddress

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.1
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