Represents the error that occurs when an argument passed to a method is invalid because it is null . [Edit]

See Also: ArgumentNullException Members

System.Object
     System.Exception
          System.SystemException
               System.ArgumentException
                    System.ArgumentNullException

[System.Runtime.InteropServices.ComVisible(true)] public class ArgumentNullException : ArgumentException

Thread Safety

All public static members of this type are safe for multithreaded operations. No instance members are guaranteed to be thread safe.

Remarks

Note:

ArgumentNullException is thrown when a method is invoked and at least one of the passed arguments is null and should never be null .

ArgumentNullException behaves identically to ArgumentException. It is provided so that application code can differentiate between exceptions caused by null arguments and exceptions caused by non-null arguments. For errors caused by non-null arguments, see ArgumentOutOfRangeException .

[Edit]

Example

The following example demonstrates an error that causes the string class to throw a ArgumentNullException exception.

C# Example

using System; class ArgumentNullTest { public static void Main() { String[] s = null; String sep = " "; try { String j = String.Join(sep,s); } catch (ArgumentNullException e) { Console.WriteLine("Error: {0}",e); } } }

The output is

Error: System.ArgumentNullException: Value cannot be null.
Parameter name: value
at System.String.Join(String separator, String[] value)
at ArgumentNullTest.Main()

Requirements

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0