PowerShell
PowerShellクラス

前書き

メソッドとプロパティ

class Person {
    [string] $FirstName
    [string] $LastName
    [string] Greeting() {
        return "Greetings, {0} {1}!" -f $this.FirstName, $this.LastName
    }
}

$x = [Person]::new()
$x.FirstName = "Jane"
$x.LastName = "Doe"
$greeting = $x.Greeting() # "Greetings, Jane Doe!"

クラスの利用可能なコンストラクタをリストする

PS> [DateTime]::new

OverloadDefinitions
-------------------
datetime new(long ticks)
datetime new(long ticks, System.DateTimeKind kind)
datetime new(int year, int month, int day)
datetime new(int year, int month, int day, System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second)
datetime new(int year, int month, int day, int hour, int minute, int second, System.DateTimeKind kind)
datetime new(int year, int month, int day, int hour, int minute, int second, System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond, System.DateTimeKind kind)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond,
System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond,
System.Globalization.Calendar calendar, System.DateTimeKind kind)

これは、どのメソッドのオーバーロード定義をリストするのにも使用できる同じテクニックです

> 'abc'.CompareTo

OverloadDefinitions
-------------------
int CompareTo(System.Object value)
int CompareTo(string strB)
int IComparable.CompareTo(System.Object obj)
int IComparable[string].CompareTo(string other)

以前のバージョンでは、使用可能なコンストラクタをリストする独自の関数を作成できます。

function Get-Constructor {
    [CmdletBinding()]
    param(
        [Parameter(ValueFromPipeline=$true)]
        [type]$type
    )

    Process {
        $type.GetConstructors() | 
        Format-Table -Wrap @{
            n="$($type.Name) Constructors"
            e={ ($_.GetParameters() | % { $_.ToString() }) -Join ", " }
        }
    }
}

使用法：

Get-Constructor System.DateTime    
#Or [datetime] | Get-Constructor

DateTime Constructors
---------------------
Int64 ticks
Int64 ticks, System.DateTimeKind kind
Int32 year, Int32 month, Int32 day
Int32 year, Int32 month, Int32 day, System.Globalization.Calendar calendar
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, System.DateTimeKind kind
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, System.Globalization.Calendar calendar
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond, System.DateTimeKind kind
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond, System.Globalization.Cal
endar calendar
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond, System.Globalization.Cal
endar calendar, System.DateTimeKind kind

コンストラクタのオーバーロード

class Person {
    [string] $Name
    [int] $Age

    Person([string] $Name) {
        $this.Name = $Name
    }

    Person([string] $Name, [int]$Age) {
        $this.Name = $Name
        $this.Age = $Age
    }
}

インスタンスのすべてのメンバーを取得する

PS > Get-Member -InputObject $anObjectInstance

これは、型インスタンスのすべてのメンバーを返します。以下は、Stringインスタンスのサンプル出力の一部です

   TypeName: System.String

Name             MemberType            Definition
----             ----------            ----------
Clone            Method                System.Object Clone(), System.Object ICloneable.Clone()
CompareTo        Method                int CompareTo(System.Object value), int CompareTo(string strB), i...
Contains         Method                bool Contains(string value)
CopyTo           Method                void CopyTo(int sourceIndex, char[] destination, int destinationI...
EndsWith         Method                bool EndsWith(string value), bool EndsWith(string value, System.S...
Equals           Method                bool Equals(System.Object obj), bool Equals(string value), bool E...
GetEnumerator    Method                System.CharEnumerator GetEnumerator(), System.Collections.Generic...
GetHashCode      Method                int GetHashCode()
GetType          Method                type GetType()
...

基本クラステンプレート

# Define a class
class TypeName
{
   # Property with validate set
   [ValidateSet("val1", "Val2")]
   [string] $P1

   # Static property
   static [hashtable] $P2

   # Hidden property does not show as result of Get-Member
   hidden [int] $P3

   # Constructor
   TypeName ([string] $s)
   {
       $this.P1 = $s       
   }

   # Static method
   static [void] MemberMethod1([hashtable] $h)
   {
       [TypeName]::P2 = $h
   }

   # Instance method
   [int] MemberMethod2([int] $i)
   {
       $this.P3 = $i
       return $this.P3
   }
}

親クラスから子クラスへの継承

class ParentClass
{
    [string] $Message = "Its under the Parent Class"

    [string] GetMessage()
    {
        return ("Message: {0}" -f $this.Message)
    }
}

# Bar extends Foo and inherits its members
class ChildClass : ParentClass
{

}
$Inherit = [ChildClass]::new()

そう、 $ Inherit.Messageはあなたに

「その親クラスの下に」