如何在PowerShell调用Dll文件。

PowerShell中可以直接使用.NET的Dll库，通过如下语句:
[system.reflection.Assembly]::LoadFrom("dll所在绝对路径");

但是传统的非.NET生成的Dll库如何使用呢？
比较复杂,基本可以按照下列语句来使用:
$dir="C:\\curl-7.16.4\\FTCTRLPRO3.dll"
$ctor = [Runtime.InteropServices.DllImportAttribute].GetConstructor([string])
$attr = New-Object Reflection.Emit.CustomAttributeBuilder $ctor, $dir

这只能简单载入Dll，如果想使用Dll的具体的函数，可以参看如下文章:
http://www.leeholmes.com/blog/ManagingINIFilesWithPowerShell.aspx
##############################################################################
##
## Invoke-WindowsApi.ps1
##
## From PowerShell Cookbook (O'Reilly)
## by Lee Holmes (http://www.leeholmes.com/guide)
##
## Invoke a native Windows API call that takes and returns simple data types.
##
## ie:
##
## ## Prepare the parameter types and parameters for the
## CreateHardLink function
## $parameterTypes = [string], [string], [IntPtr]
## $parameters = [string] $filename, [string] $existingFilename, [IntPtr]::Zero
##
## ## Call the CreateHardLink method in the Kernel32 DLL
## $result = Invoke-WindowsApi "kernel32" ([bool]) "CreateHardLink" `
## $parameterTypes $parameters
##
##############################################################################

param(
[string] $dllName,
[Type] $returnType,
[string] $methodName,
[ Type[]] $parameterTypes,
[Object[]] $parameters
)

## Begin to build the dynamic assembly
$domain = [AppDomain]::CurrentDomain
$name = New-Object Reflection.AssemblyName 'PInvokeAssembly'
$assembly = $domain.DefineDynamicAssembly( $name, 'Run')

- Show quoted text -

$module = $assembly.DefineDynamicModule( 'PInvokeModule')
$type = $module.DefineType('PInvokeType', "Public,BeforeFieldInit")

## Go through all of the parameters passed to us. As we do this,
## we clone the user's inputs into another array that we will use for
## the P/Invoke call.
$inputParameters = @()
$refParameters = @()

for($counter = 1; $counter -le $parameterTypes.Length; $counter++)
{
## If an item is a PSReference, then the user
## wants an [out] parameter.
if($parameterTypes[$counter - 1] -eq [Ref])
{
## Remember which parameters are used for [Out] parameters
$refParameters += $counter

## On the cloned array, we replace the PSReference type with the
## .Net reference type that represents the value of the PSReference,
## and the value with the value held by the PSReference.
$parameterTypes[ $counter - 1] =
$parameters[$counter - 1 ].Value.GetType().MakeByRefType()
$inputParameters += $parameters[$counter - 1].Value
}
else
{
## Otherwise, just add their actual parameter to the
## input array.
$inputParameters += $parameters[$counter - 1]
}
}

## Define the actual P/Invoke method, adding the [Out]
## attribute for any parameters that were originally [Ref]
## parameters.
$method = $type.DefineMethod( $methodName, 'Public,HideBySig,Static,PinvokeImpl',
$returnType, $parameterTypes )
foreach($refParameter in $refParameters)
{

[void] $method.DefineParameter($refParameter, "Out", $null)
}

## Apply the P/Invoke constructor
$ctor = [Runtime.InteropServices.DllImportAttribute ].GetConstructor([string])
$attr = New-Object Reflection.Emit.CustomAttributeBuilder $ctor, $dllName
$method.SetCustomAttribute($attr)

## Create the temporary type, and invoke the method.
$realType = $type.CreateType()

$realType.InvokeMember($methodName, 'Public,Static,InvokeMethod', $null, $null,
$inputParameters)

## Finally, go through all of the reference parameters, and update the
## values of the PSReference objects that the user passed in.
foreach($refParameter in $refParameters)
{
$parameters[$refParameter - 1].Value = $inputParameters[$refParameter - 1]
}