Add-Type

Add a .NET Framework type to a PowerShell session. If a .NET Framework class is added to your PowerShell session with Add-Type, those objects may then be instantiated (with New-Object ), just like any .NET Framework object.
Syntax
      Add-Type -AssemblyName string[]
         [-IgnoreWarnings] [-PassThru] [CommonParameters]
    
      Add-Type [-Name] string [-MemberDefinition] string[]
         [-CodeDomProvider CodeDomProvider] [-CompilerParameters CompilerParameters]
            [-Language {CSharp | CSharpVersion3 | VisualBasic | JScript}]
               [-Namespace string] [-OutputAssembly string]
                  [-OutputType OutputAssemblyType] [-ReferencedAssemblies string[]]
                     [-UsingNamespace string[]] [-IgnoreWarnings] [-PassThru] [CommonParameters]
    
      Add-Type [-Path] string[] [-CompilerParameters CompilerParameters]
        [-OutputAssembly string]
           [-OutputType OutputAssemblyType] [-ReferencedAssemblies string[]]
              [-IgnoreWarnings] [-PassThru] [CommonParameters]
    
      Add-Type [-TypeDefinition] string [-CodeDomProvider CodeDomProvider]
         [-CompilerParameters CompilerParameters]
            [-Language {CSharp | CSharpVersion3 | VisualBasic | JScript}]
               [-OutputAssembly string] [-OutputType OutputAssemblyType]
                  [-ReferencedAssemblies string[]] [-IgnoreWarnings] 
                     [-PassThru] [CommonParameters]

key
   -AssemblyName 
      The name of an assembly that includes the types. Wildcard characters are permitted
      This parameter does not accept a path or file name. To enter the path to the assembly DLL, use -Path.

   -CodeDomProvider
      A code generator or compiler. The default is the CSharp compiler.

   -CompilerParameters
      The options for the source code compiler.
      These options are sent to the compiler without revision.
        
    -IgnoreWarnings
      Ignores compiler warnings. Dont handle compiler warnings as errors.

   -Language
      Specifies the language used in the source code.
      Valid values are "CSharp", "CSharpVersion3", "VisualBasic", and "JScript".
      "CSharp" is the default.

   -MemberDefinition 
      Specify new properties or methods for the class.

   -Name
      The name of the class to create. Required when generating a type from a member definition.

   -Namespace
      A namespace for the type. 

   -OutputAssembly
      Generate a DLL file for the assembly with the specified name in the location.
      By default, Add-Type generates the assembly only in memory.

   -OutputType 
      The output type of the output assembly. 
      Valid values are Library, ConsoleApplication, and WindowsApplication. 
      By default, no output type is specified.

   -PassThru
      Return a System.Runtime object that represents the types that were added.

   -Path
      The path to source code files or assembly DLL files that contain the types.

   -ReferencedAssemblies 
      The assemblies upon which the type depends in addition to the default references,
      System.dll and System.Management.Automation.dll

   -TypeDefinition 
      The source code that contains the type definitions. Enter the source code in a
      string or here-string, or enter a variable that contains the source code.

   -UsingNamespace
      Other namespaces that are required for the class.
      This is much like the Using keyword in C#.

   CommonParameters
       -Verbose, -Debug, -ErrorAction, -ErrorVariable, -WarningAction,
        -WarningVariable, -OutBuffer and -OutVariable
Examples
"get-help Add-Type -examples"
“If you don't have time to do it right, when will you have time to do it over?” - John Wooden