Add-Type
Adds a Microsoft .NET class to a PowerShell session.
Syntax
Add-Type
[-CodeDomProvider <CodeDomProvider>]
[-CompilerParameters <CompilerParameters>]
[-TypeDefinition] <String>
[-Language <Language>]
[-ReferencedAssemblies <String[]>]
[-OutputAssembly <String>]
[-OutputType <OutputAssemblyType>]
[-PassThru]
[-IgnoreWarnings]
[<CommonParameters>]
Add-Type
[-CodeDomProvider <CodeDomProvider>]
[-CompilerParameters <CompilerParameters>]
[-Name] <String>
[-MemberDefinition] <String[]>
[-Namespace <String>]
[-UsingNamespace <String[]>]
[-Language <Language>]
[-ReferencedAssemblies <String[]>]
[-OutputAssembly <String>]
[-OutputType <OutputAssemblyType>]
[-PassThru]
[-IgnoreWarnings]
[<CommonParameters>]
Add-Type
[-CompilerParameters <CompilerParameters>]
[-Path] <String[]>
[-ReferencedAssemblies <String[]>]
[-OutputAssembly <String>]
[-OutputType <OutputAssemblyType>]
[-PassThru]
[-IgnoreWarnings]
[<CommonParameters>]
Add-Type
[-CompilerParameters <CompilerParameters>]
-LiteralPath <String[]>
[-ReferencedAssemblies <String[]>]
[-OutputAssembly <String>]
[-OutputType <OutputAssemblyType>]
[-PassThru]
[-IgnoreWarnings]
[<CommonParameters>]
Add-Type
-AssemblyName <String[]>
[-PassThru]
[-IgnoreWarnings]
[<CommonParameters>]
Description
The Add-Type
cmdlet lets you define a Microsoft .NET Framework class in your PowerShell session.
You can then instantiate objects, by using the New-Object
cmdlet, and use the objects just as you
would use any .NET Framework object. If you add an Add-Type
command to your PowerShell profile,
the class is available in all PowerShell sessions.
You can specify the type by specifying an existing assembly or source code files, or you can specify
the source code inline or saved in a variable. You can even specify only a method and Add-Type
will define and generate the class. On Windows, you can use this feature to make Platform Invoke
(P/Invoke) calls to unmanaged functions in PowerShell. If you specify source code, Add-Type
compiles the specified source code and generates an in-memory assembly that contains the new .NET
Framework types.
You can use the parameters of Add-Type
to specify an alternate language and compiler, C# is the
default, compiler options, assembly dependencies, the class namespace, the names of the type, and
the resulting assembly.
Examples
Example 1: Add a .NET type to a session
This example adds the BasicTest class to the session by specifying source code that is stored in a variable. The BasicTest class is used to add integers, create an object, and multiply integers.
$Source = @"
public class BasicTest
{
public static int Add(int a, int b)
{
return (a + b);
}
public int Multiply(int a, int b)
{
return (a * b);
}
}
"@
Add-Type -TypeDefinition $Source
[BasicTest]::Add(4, 3)
$BasicTestObject = New-Object BasicTest
$BasicTestObject.Multiply(5, 2)
The $Source
variable stores the source code for the class. The type has a static method called
Add
and a non-static method called Multiply
.
The Add-Type
cmdlet adds the class to the session. Because it's using inline source code, the
command uses the TypeDefinition parameter to specify the code in the $Source
variable.
The Add
static method of the BasicTest class uses the double-colon characters (::
) to
specify a static member of the class. The integers are added and the sum is displayed.
The New-Object
cmdlet instantiates an instance of the BasicTest class. It saves the new object
in the $BasicTestObject
variable.
$BasicTestObject
uses the Multiply
method. The integers are multiplied and the product is
displayed.
Example 2: Examine an added type
This example uses the Get-Member
cmdlet to examine the objects that the Add-Type
and
New-Object
cmdlets created in Example 1.
[BasicTest] | Get-Member
TypeName: System.RuntimeType
Name MemberType Definition
---- ---------- ----------
AsType Method type AsType()
Clone Method System.Object Clone(), System.Object ICloneable.Clone()
Equals Method bool Equals(System.Object obj), bool Equals(type o)
FindInterfaces Method type[] FindInterfaces(System.Reflection.TypeFilter filter...
...
[BasicTest] | Get-Member -Static
TypeName: BasicTest
Name MemberType Definition
---- ---------- ----------
Add Method static int Add(int a, int b)
Equals Method static bool Equals(System.Object objA, System.Object objB)
new Method BasicTest new()
ReferenceEquals Method static bool ReferenceEquals(System.Object objA, System.Object objB)
$BasicTestObject | Get-Member
TypeName: BasicTest
Name MemberType Definition
---- ---------- ----------
Equals Method bool Equals(System.Object obj)
GetHashCode Method int GetHashCode()
GetType Method type GetType()
Multiply Method int Multiply(int a, int b)
ToString Method string ToString()
The Get-Member
cmdlet gets the type and members of the BasicTest class that Add-Type
added
to the session. The Get-Member
command reveals that it's a System.RuntimeType object, which is
derived from the System.Object class.
The Get-Member
Static parameter gets the static properties and methods of the BasicTest
class. The output shows that the Add
method is included.
The Get-Member
cmdlet gets the members of the object stored in the $BasicTestObject
variable.
$BasicTestObject
was created by using the New-Object
cmdlet with the BasicTest class. The
output reveals that the value of the $BasicTestObject
variable is an instance of the BasicTest
class and that it includes a member called Multiply
.
Example 3: Add types from an assembly
This example adds the classes from the Accessibility.dll
assembly to the current session.
$AccType = Add-Type -AssemblyName "accessib*" -PassThru
The $AccType
variable stores an object created with the Add-Type
cmdlet. Add-Type
uses the
AssemblyName parameter to specify the name of the assembly. The asterisk (*
) wildcard
character allows you to get the correct assembly even when you aren't sure of the name or its
spelling. The PassThru parameter generates objects that represent the classes that are added to
the session.
Example 4: Call native Windows APIs
This example demonstrates how to call native Windows APIs in PowerShell. Add-Type
uses the
Platform Invoke (P/Invoke) mechanism to call a function in User32.dll
from PowerShell. This
example only works on computers running the Windows operating system.
$Signature = @"
[DllImport("user32.dll")]public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
"@
$addTypeSplat = @{
MemberDefinition = $Signature
Name = "Win32ShowWindowAsync"
Namespace = 'Win32Functions'
PassThru = $true
}
$ShowWindowAsync = Add-Type @addTypeSplat
# Minimize the PowerShell console
$ShowWindowAsync::ShowWindowAsync((Get-Process -Id $pid).MainWindowHandle, 2)
# Restore the PowerShell console
$ShowWindowAsync::ShowWindowAsync((Get-Process -Id $Pid).MainWindowHandle, 4)
The $Signature
variable stores the C# signature of the ShowWindowAsync
function. To ensure that
the resulting method is visible in a PowerShell session, the public
keyword was added to the
standard signature. For more information, see
ShowWindowAsync function.
The $ShowWindowAsync
variable stores the object created by the Add-Type
PassThru parameter.
The Add-Type
cmdlet adds the ShowWindowAsync
function to the PowerShell session as a static
method. The command uses the MemberDefinition parameter to specify the method definition saved
in the $Signature
variable. The command uses the Name and Namespace parameters to specify
a name and namespace for the class. The PassThru parameter generates an object that represents
the types.
The new ShowWindowAsync
static method is used in the commands to minimize and restore the
PowerShell console. The method takes two parameters: the window handle, and an integer that
specifies how the window is displayed.
To minimize the PowerShell console, ShowWindowAsync
uses the Get-Process
cmdlet with the $PID
automatic variable to get the process that is hosting the current PowerShell session. Then it uses
the MainWindowHandle property of the current process and a value of 2
, which represents the
SW_MINIMIZE
value.
To restore the window, ShowWindowAsync
uses a value of 4
for the window position, which
represents the SW_RESTORE
value.
To maximize the window, use the value of 3
that represents SW_MAXIMIZE
.
Example 5: Add a type from a Visual Basic file
This example uses the Add-Type
cmdlet to add the VBFromFile class that's defined in the
Hello.vb
file to the current session. The text of the Hello.vb
file is shown in the command
output.
Add-Type -Path "C:\PS-Test\Hello.vb"
[VBFromFile]::SayHello(", World")
# From Hello.vb
Public Class VBFromFile
Public Shared Function SayHello(sourceName As String) As String
Dim myValue As String = "Hello"
return myValue + sourceName
End Function
End Class
Hello, World
Add-Type
uses the Path parameter to specify the source file, Hello.vb
, and adds the type
defined in the file. The SayHello
function is called as a static method of the VBFromFile
class.
Example 6: Add a class with JScript.NET
This example uses JScript.NET to create a new class, FRectangle, in your PowerShell session.
Add-Type @'
class FRectangle {
var Length : double;
var Height : double;
function Perimeter() : double {
return (Length + Height) * 2; }
function Area() : double {
return Length * Height; } }
'@ -Language JScript
$rect = [FRectangle]::new()
$rect
Length Height
------ ------
0 0
Example 7: Add an F# compiler
This example shows how to use the Add-Type
cmdlet to add an F# code compiler to your PowerShell
session. To run this example in PowerShell, you must have the FSharp.Compiler.CodeDom.dll
that is
installed with the F# language.
Add-Type -Path "FSharp.Compiler.CodeDom.dll"
$Provider = New-Object Microsoft.FSharp.Compiler.CodeDom.FSharpCodeProvider
$FSharpCode = @"
let rec loop n =if n <= 0 then () else beginprint_endline (string_of_int n);loop (n-1)end
"@
$FSharpType = Add-Type -TypeDefinition $FSharpCode -CodeDomProvider $Provider -PassThru |
Where-Object { $_.IsPublic }
$FSharpType::loop(4)
4
3
2
1
Add-Type
uses the Path parameter to specify an assembly and gets the types in the assembly.
New-Object
creates an instance of the F# code provider and saves the result in the $Provider
variable. The $FSharpCode
variable saves the F# code that defines the Loop method.
The $FSharpType
variable stores the results of the Add-Type
cmdlet that saves the public
types defined in $FSharpCode
. The TypeDefinition parameter specifies the source code that
defines the types. The CodeDomProvider parameter specifies the source code compiler. The
PassThru parameter directs Add-Type
to return a Runtime object that represents the types.
The objects are sent down the pipeline to the Where-Object
cmdlet, which returns only the public
types. The Where-Object
cmdlet is used because the F# provider generates non-public types to
support the resulting public type.
The Loop method is called as a static method of the type stored in the $FSharpType
variable.
Parameters
-AssemblyName
Specifies the name of an assembly that includes the types. Add-Type
takes the types from the
specified assembly. This parameter is required when you're creating types based on an assembly name.
Enter the full or simple name, also known as the partial name, of an assembly. Wildcard characters
are permitted in the assembly name. If you enter a simple or partial name, Add-Type
resolves it to
the full name, and then uses the full name to load the assembly.
Using the Path or LiteralPath parameters guarantees that you are loading the assembly that
you intended to load. When you use the AssemblyName parameter, PowerShell asks .NET to resolve
the assembly name using the standard .NET assembly resolution process. Since .NET searches the
application folder first, Add-Type
might load an assembly from $PSHOME
instead of the version in
the current folder. For more information, see
Assembly location.
If .NET fails to resolve the name, PowerShell then looks in the current location to find the assembly. When you use wildcards in the AssemblyName parameter, the .NET assembly resolution process fails causing PowerShell to look in the current location.
Type: | String[] |
Aliases: | AN |
Position: | Named |
Default value: | None |
Required: | True |
Accept pipeline input: | False |
Accept wildcard characters: | True |
-CodeDomProvider
Specifies a code generator or compiler. Add-Type
uses the specified compiler to compile the source
code. The default is the C# compiler. Use this parameter if you're using a language that can't be
specified by using the Language parameter. The CodeDomProvider that you specify must be able
to generate assemblies from source code.
Type: | CodeDomProvider |
Aliases: | Provider |
Position: | Named |
Default value: | C# compiler |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-CompilerParameters
Specifies the options for the source code compiler. These options are sent to the compiler without revision.
This parameter allows you to direct the compiler to generate an executable file, embed resources, or
set command-line options, such as the /unsafe
option. This parameter implements the
CompilerParameters class, System.CodeDom.Compiler.CompilerParameters.
You can't use the CompilerParameters and ReferencedAssemblies parameters in the same command.
Type: | CompilerParameters |
Aliases: | CP |
Position: | Named |
Default value: | None |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-IgnoreWarnings
Ignores compiler warnings. Use this parameter to prevent Add-Type
from handling compiler warnings
as errors.
Type: | SwitchParameter |
Position: | Named |
Default value: | False |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-Language
Specifies the language that is used in the source code. The Add-Type
cmdlet uses the value of this
parameter to select the appropriate CodeDomProvider. CSharp is the default value. The acceptable
values for this parameter are as follows:
CSharp
CSharpVersion2
CSharpVersion3
JScript
VisualBasic
Type: | Language |
Accepted values: | CSharp, CSharpVersion2, CSharpVersion3, JScript, VisualBasic |
Position: | Named |
Default value: | CSharp |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-LiteralPath
Specifies the path to source code files or assembly DLL files that contain the types. Unlike Path, the value of the LiteralPath parameter is used exactly as it's typed. No characters are interpreted as wildcards. If the path includes escape characters, enclose it in single quotation marks. Single quotation marks tell PowerShell not to interpret any characters as escape sequences.
Using the Path or LiteralPath parameters guarantees that you are loading the assembly that you intended to load.
Type: | String[] |
Aliases: | PSPath |
Position: | Named |
Default value: | None |
Required: | True |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-MemberDefinition
Specifies new properties or methods for the class. Add-Type
generates the template code that is
required to support the properties or methods.
On Windows, you can use this feature to make Platform Invoke (P/Invoke) calls to unmanaged functions in PowerShell.
Type: | String[] |
Position: | 1 |
Default value: | None |
Required: | True |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-Name
Specifies the name of the class to create. This parameter is required when generating a type from a member definition.
The type name and namespace must be unique within a session. You can't unload a type or change it. To change the code for a type, you must change the name or start a new PowerShell session. Otherwise, the command fails.
Type: | String |
Position: | 0 |
Default value: | None |
Required: | True |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-Namespace
Specifies a namespace for the type.
If this parameter isn't included in the command, the type is created in the
Microsoft.PowerShell.Commands.AddType.AutoGeneratedTypes namespace. If the parameter is included
in the command with an empty string value or a value of $Null
, the type is generated in the global
namespace.
Type: | String |
Aliases: | NS |
Position: | Named |
Default value: | None |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-OutputAssembly
Generates a DLL file for the assembly with the specified name in the location. Enter an optional
path and filename. Wildcard characters are permitted. By default, Add-Type
generates the assembly
only in memory.
Type: | String |
Aliases: | OA |
Position: | Named |
Default value: | None |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | True |
-OutputType
Specifies the output type of the output assembly. By default, no output type is specified. This parameter is valid only when an output assembly is specified in the command. For more information about the values, see OutputAssemblyType Enumeration.
The acceptable values for this parameter are as follows:
ConsoleApplication
Library
WindowsApplication
Type: | OutputAssemblyType |
Aliases: | OT |
Accepted values: | ConsoleApplication, Library, WindowsApplication |
Position: | Named |
Default value: | None |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-PassThru
Returns a System.Runtime object that represents the types that were added. By default, this cmdlet doesn't generate any output.
Type: | SwitchParameter |
Position: | Named |
Default value: | False |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-Path
Specifies the path to source code files or assembly DLL files that contain the types.
If you submit source code files, Add-Type
compiles the code in the files and creates an in-memory
assembly of the types. The file extension specified in the value of Path determines the compiler
that Add-Type
uses.
If you submit an assembly file, Add-Type
takes the types from the assembly. To specify an
in-memory assembly or the global assembly cache, use the AssemblyName parameter.
Type: | String[] |
Position: | 0 |
Default value: | None |
Required: | True |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-ReferencedAssemblies
Specifies the assemblies upon which the type depends. By default, Add-Type
references System.dll
and System.Management.Automation.dll
. The assemblies that you specify by using this parameter are
referenced in addition to the default assemblies.
You can't use the CompilerParameters and ReferencedAssemblies parameters in the same command.
Type: | String[] |
Aliases: | RA |
Position: | Named |
Default value: | None |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-TypeDefinition
Specifies 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. For more information about here-strings, see about_Quoting_Rules.
Include a namespace declaration in your type definition. If you omit the namespace declaration, your type might have the same name as another type or the shortcut for another type, causing an unintentional overwrite. For example, if you define a type called Exception, scripts that use Exception as the shortcut for System.Exception will fail.
Type: | String |
Position: | 0 |
Default value: | None |
Required: | True |
Accept pipeline input: | False |
Accept wildcard characters: | False |
-UsingNamespace
Specifies other namespaces that are required for the class. This is much like the C# keyword,
Using
.
By default, Add-Type
references the System namespace. When the MemberDefinition parameter
is used, Add-Type
also references the System.Runtime.InteropServices namespace by default. The
namespaces that you add by using the UsingNamespace parameter are referenced in addition to the
default namespaces.
Type: | String[] |
Aliases: | Using |
Position: | Named |
Default value: | System namespace |
Required: | False |
Accept pipeline input: | False |
Accept wildcard characters: | False |
Inputs
None
You can't pipe objects to this cmdlet.
Outputs
None
By default, this cmdlet returns no output.
When you use the PassThru parameter, this cmdlet returns a System.Type object representing the new type.
Notes
The types that you add exist only in the current session. To use the types in all sessions, add them to your PowerShell profile. For more information about the profile, see about_Profiles.
Type names and namespaces must be unique within a session. You can't unload a type or change it. If you need to change the code for a type, you must change the name or start a new PowerShell session. Otherwise, the command fails.
The CodeDomProvider class for some languages, such as IronPython and J#, doesn't generate
output. As a result, types written in these languages can't be used with Add-Type
.
This cmdlet is based on the Microsoft .NET Framework CodeDomProvider Class.
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