New in .NET 10.0 (29): Check IP addresses with IPAddress.IsValid()

There is a class for checking IP addresses System.Net.IPAddress the static method has been around since the .NET Framework 2.0 TryParse()which extracts an IP address from a string.

Since .NET Core 2.1 the extraction is also from the type ReadOnlySpan possible. The return value is a boolvalue and the extracted IP address is in the form of an instance of the class IPAddress as out-Parameters supplied. If you just want to check whether the IP address is correct, you write IPAddress.TryParse(eingabe, out _).

In .NET 10.0, Microsoft now provides in the static method IsValid() another test variant with less internal effort. The following code compares IsValid() with TryParse():

/// 

/// IsValid mit ReadOnlySpan oder ReadOnlySpan als Alternative zu IPAddress.TryParse(span, out _)
/// 
public void Run()
{
 CUI.Demo("IPAddress.IsValid()");

 string IP1 = "192.168.1.0"; // gültige IPv4-Adresse
 CUI.H2(IP1);

 // --- Alt
 var valid1 = IPAddress.TryParse(IP1, out _);
 Console.WriteLine("TryParse: " + valid1); // true

 // --- Neu
 System.Console.WriteLine("IsValid: " + System.Net.IPAddress.IsValid(IP1)); // true

 string IP2 = "192.168.256.1"; // ungültige IPv4-Adresse
 CUI.H2(IP2);

 // --- Alt
 var valid2 = IPAddress.TryParse(IP2, out _);
 Console.WriteLine("TryParse: " + valid2); // false

 // --- Neu
 System.Console.WriteLine("IsValid: " + System.Net.IPAddress.IsValid(IP2)); // false
}

To do this, Microsoft is now simply returning a previously internal method TargetHostNameHelper.IsValidAddress() to the outside world, as can be seen from the issue on GitHub.

(rme)