通過New-Object創建新對象
如果使用構造函數創建一個指定類型的實例對象，該類型必須至少包含一個簽名相匹配的構造函數。例如可以通過字符和數字創建一個包含指定個數字符的字符串：
PS C:Powershell> New-Object String(‘*',100)
*******************************************************************************
*********************
為什么支持上面的方法，原因是String類中包含一個Void .ctor(Char, Int32) 構造函數
PS C:Powershell> [String].GetConstructors() | foreach {$_.tostring()}
Void .ctor(Char*)
Void .ctor(Char*, Int32, Int32)
Void .ctor(SByte*)
Void .ctor(SByte*, Int32, Int32)
Void .ctor(SByte*, Int32, Int32, System.Text.Encoding)
Void .ctor(Char[], Int32, Int32)
Void .ctor(Char[])
Void .ctor(Char, Int32)
通過類型轉換創建對象
通過類型轉換可以替代New-Object
PS C:Powershell> $date="1999-9-1 10:23:44"
PS C:Powershell> $date.GetType().fullName
System.String
PS C:Powershell> $date
1999-9-1 10:23:44
PS C:Powershell> [DateTime]$date="1999-9-1 10:23:44"
PS C:Powershell> $date.GetType().FullName
System.DateTime
PS C:Powershell> $date
1999年9月1日 10:23:44
如果條件允許，也可以直接將對象轉換成數組
PS C:Powershell> [char[]]"mossfly.com"
m
o
s
s
f
l
y
.
c
o
m
PS C:Powershell> [int[]][char[]]"mossfly.com"
109
111
115
115
102
108
121
46
99
111
109
加載程序集
自定義一個簡單的C#類庫編譯為Test.dll：
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
namespace Test
{
public class Student
{
public string Name { set; get; }
public int Age { set; get; }
public Student(string name, int age)
{
this.Name = name;
this.Age = age;
}
public override string ToString()
{
return string.Format("Name={0};Age={1}", this.Name,this.Age);
}
}
}
在Powershell中加載這個dll并使用其中的Student類的構造函數生成一個實例，最后調用ToString()方法。
PS C:Powershell> ls .Test.dll
目錄: C:Powershell
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 2012/1/13 10:49 4608 Test.dll
PS C:Powershell> $TestDLL=ls .Test.dll
PS C:Powershell> [reflection.assembly]::LoadFile($TestDLL.FullName)
GAC Version Location
--- ------- --------
False v2.0.50727 C:PowershellTest.dll
PS C:Powershell> $stu=New-Object Test.Student('Mosser',22)
PS C:Powershell> $stu
Name Age
---- ---
Mosser 22
PS C:Powershell> $stu.ToString()
Name=Mosser;Age=22
使用COM對象
作為.NET的補充，Powershell可以加載和訪問COM對象。
查看可用的COM對象
每一個COM對象都有存儲在注冊表中的唯一標識符，想遍歷訪問可用的COM對象，可是直接訪問注冊表。
Dir REGISTRY::HKEY_CLASSES_ROOTCLSID -include PROGID -recurse | foreach {$_.GetValue("")}
DAO.DBEngine.36
DAO.PrivateDBEngine.36
DAO.TableDef.36
DAO.Field.36
DAO.Index.36
PS C:Powershell> Dir REGISTRY::HKEY_CLASSES_ROOTCLSID -include PROGID -recurse
| foreach {$_.GetValue("")} | select -First 10
DAO.DBEngine.36
DAO.PrivateDBEngine.36
DAO.TableDef.36
DAO.Field.36
DAO.Index.36
DAO.Group.36
DAO.User.36
DAO.QueryDef.36
DAO.Relation.36
file
......
怎樣使用COM對象
一旦得到了COM對象的ProgID，就可以使用New-Object創建COM對象，只需要指定參數為-comObject。
PS C:Powershell> New-Object -ComObject DAO.Relation.36
Properties : System.__ComObject
Name :
Table :
ForeignTable :
Attributes : 0
Fields : System.__ComObject
PartialReplica :
COM對象的和.NET對象相似，任然可是使用Get-Member 得到該對象的所有熟悉和方法：
PS C:Powershell> $DBEng=New-Object -ComObject DAO.PrivateDBEngine.36
PS C:Powershell> $DBEng | Get-Member -me *method
TypeName: System.__ComObject#{00000021-0000-0010-8000-00aa006d2ea4}
Name MemberType Definition
---- ---------- ----------
BeginTrans Method void BeginTrans ()
CommitTrans Method void CommitTrans (int)
CompactDatabase Method void CompactDatabase (string, string, Variant...
CreateDatabase Method Database CreateDatabase (string, string, Vari...
CreateWorkspace Method Workspace CreateWorkspace (string, string, st...
FreeLocks Method void FreeLocks ()
Idle Method void Idle (Variant)
ISAMStats Method int ISAMStats (int, Variant)
OpenConnection Method Connection OpenConnection (string, Variant, V...
OpenDatabase Method Database OpenDatabase (string, Variant, Varia...
RegisterDatabase Method void RegisterDatabase (string, string, bool, ...
RepairDatabase Method void RepairDatabase (string)
Rollback Method void Rollback ()
SetDataAccessOption Method void SetDataAccessOption (short, Variant)
SetDefaultWorkspace Method void SetDefaultWorkspace (string, string)
SetOption Method void SetOption (int, Variant)
_30_CreateWorkspace Method Workspace _30_CreateWorkspace (string, string...
PS C:Powershell> $DBEng | Get-Member -me *property
TypeName: System.__ComObject#{00000021-0000-0010-8000-00aa006d2ea4}
Name MemberType Definition
---- ---------- ----------
DefaultPassword Property string DefaultPassword () {set}
DefaultType Property int DefaultType () {get} {set}
DefaultUser Property string DefaultUser () {set}
Errors Property Errors Errors () {get}
IniPath Property string IniPath () {get} {set}
LoginTimeout Property short LoginTimeout () {get} {set}
Properties Property Properties Properties () {get}
SystemDB Property string SystemDB () {get} {set}
Version Property string Version () {get}
Workspaces Property Workspaces Workspaces () {get}
常用的COM對象中有
WScript.Shell,
WScript.Network,
Scripting.FileSystemObject,
InternetExplorer.Application,
Word.Application,
Shell.Application
下面的例子使用WScript.shell COM對象和它的方法CreateShortcut()做桌面上創建一個Powershell快捷方式：
PS C:Powershell> $wshell=New-Object -ComObject WScript.shell
PS C:Powershell> $path=[environment]::GetFolderPath('Desktop')
PS C:Powershell> $link=$wshell.CreateShortcut("$pathPowershell.lnk")
PS C:Powershell> $link | Get-Member
TypeName: System.__ComObject#{f935dc23-1cf0-11d0-adb9-00c04fd58a0b}
Name MemberType Definition
---- ---------- ----------
Load Method void Load (string)
Save Method void Save ()
Arguments Property string Arguments () {get} {set}
Description Property string Description () {get} {set}
FullName Property string FullName () {get}
Hotkey Property string Hotkey () {get} {set}
IconLocation Property string IconLocation () {get} {set}
RelativePath Property string RelativePath () {set}
TargetPath Property string TargetPath () {get} {set}
WindowStyle Property int WindowStyle () {get} {set}
WorkingDirectory Property string WorkingDirectory () {get} {set}
PS C:Powershell> $link.TargetPath='Powershell.exe'
PS C:Powershell> $link.Description="啟動Powershell"
PS C:Powershell> $link.WorkingDirectory=$PROFILE
PS C:Powershell> $link.IconLocation='Powershell.exe'
PS C:Powershell> $link.Save()
