关于Windows：如何从shell32.dll中获取图标？

#Windows PowerShell Code###########################################################################
# http://gallery.technet.microsoft.com/scriptcenter/Icon-Exporter-e372fe70
#
# AUTHOR: John Grenfell
#
###########################################################################

<#
.SYNOPSIS
   Exports an ico and bmp file from a given source to a given destination
.Description
   You need to set the Source and Destination locations. First version of a script, I found other examples but all I wanted to do as grab and ico file from an exe but found getting a bmp useful. Others might find useful
   No error checking I'm afraid so make sure your source and destination locations exist!
.EXAMPLE
    .\\Icon_Exporter.ps1
.Notes
        Version HISTORY:
        1.1 2012.03.8
#>
Param ( [parameter(Mandatory = $true)][string] $SourceEXEFilePath,
        [parameter(Mandatory = $true)][string] $TargetIconFilePath
)
CLS
#"shell32.dll" 238
If ($SourceEXEFilePath.ToLower().Contains(".dll")) {
    $IconIndexNo = Read-Host"Enter the icon index:"
    $Icon = [System.IconExtractor]::Extract($SourceEXEFilePath, $IconIndexNo, $true)    
} Else {
    [void][Reflection.Assembly]::LoadWithPartialName("System.Drawing")
    [void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
    $image = [System.Drawing.Icon]::ExtractAssociatedIcon("$($SourceEXEFilePath)").ToBitmap()
    $bitmap = new-object System.Drawing.Bitmap $image
    $bitmap.SetResolution(72,72)
    $icon = [System.Drawing.Icon]::FromHandle($bitmap.GetHicon())
}
$stream = [System.IO.File]::OpenWrite("$($TargetIconFilePath)")
$icon.save($stream)
$stream.close()
Write-Host"Icon file can be found at $TargetIconFilePath"

    <#
.SYNOPSIS
    Exports an ico and bmp file from a given source to a given destination
.Description
    You need to set the Source and Destination locations. First version of a script, I found other examples
    but all I wanted to do as grab and ico file from an exe but found getting a bmp useful. Others might find useful
.EXAMPLE
    This will run but will nag you for input
    .\\Icon_Exporter.ps1
.EXAMPLE
    this will default to shell32.dll automatically for -SourceEXEFilePath
    .\\Icon_Exporter.ps1 -TargetIconFilePath 'C:\\temp\\Myicon.ico' -IconIndexNo 238
.EXAMPLE
    This will give you a green tree icon (press F5 for windows to refresh Windows explorer)
    .\\Icon_Exporter.ps1 -SourceEXEFilePath 'C:/Windows/system32/shell32.dll' -TargetIconFilePath 'C:\\temp\\Myicon.ico' -IconIndexNo 41

.Notes
    Based on http://stackoverflow.com/questions/8435/how-do-you-get-the-icons-out-of-shell32-dll Version 1.1 2012.03.8
    New version: Version 1.2 2015.11.20 (Added missing custom assembly and some error checking for novices)
#>
Param (
    [parameter(Mandatory = $true)]
    [string] $SourceEXEFilePath = 'C:/Windows/system32/shell32.dll',
    [parameter(Mandatory = $true)]
    [string] $TargetIconFilePath,
    [parameter(Mandatory = $False)]
    [Int32]$IconIndexNo = 0
)

#https://social.technet.microsoft.com/Forums/windowsserver/en-US/16444c7a-ad61-44a7-8c6f-b8d619381a27/using-icons-in-powershell-scripts?forum=winserverpowershell
$code = @"
using System;
using System.Drawing;
using System.Runtime.InteropServices;

namespace System
{
    public class IconExtractor
    {

     public static Icon Extract(string file, int number, bool largeIcon)
     {
      IntPtr large;
      IntPtr small;
      ExtractIconEx(file, number, out large, out small, 1);
      try
      {
       return Icon.FromHandle(largeIcon ? large : small);
      }
      catch
      {
       return null;
      }

     }
     [DllImport("Shell32.dll", EntryPoint ="ExtractIconExW", CharSet = CharSet.Unicode, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
     private static extern int ExtractIconEx(string sFile, int iIndex, out IntPtr piLargeVersion, out IntPtr piSmallVersion, int amountIcons);

    }
}
"@

If  (-not (Test-path -Path $SourceEXEFilePath -ErrorAction SilentlyContinue ) ) {
    Throw"Source file [$SourceEXEFilePath] does not exist!"
}

[String]$TargetIconFilefolder = [System.IO.Path]::GetDirectoryName($TargetIconFilePath)
If  (-not (Test-path -Path $TargetIconFilefolder -ErrorAction SilentlyContinue ) ) {
    Throw"Target folder [$TargetIconFilefolder] does not exist!"
}

Try {
    If ($SourceEXEFilePath.ToLower().Contains(".dll")) {
        Add-Type -TypeDefinition $code -ReferencedAssemblies System.Drawing
        $form = New-Object System.Windows.Forms.Form
        $Icon = [System.IconExtractor]::Extract($SourceEXEFilePath, $IconIndexNo, $true)    
    } Else {
        [void][Reflection.Assembly]::LoadWithPartialName("System.Drawing")
        [void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
        $image = [System.Drawing.Icon]::ExtractAssociatedIcon("$($SourceEXEFilePath)").ToBitmap()
        $bitmap = new-object System.Drawing.Bitmap $image
        $bitmap.SetResolution(72,72)
        $icon = [System.Drawing.Icon]::FromHandle($bitmap.GetHicon())
    }
} Catch {
    Throw"Error extracting ICO file"
}

Try {
    $stream = [System.IO.File]::OpenWrite("$($TargetIconFilePath)")
    $icon.save($stream)
    $stream.close()
} Catch {
    Throw"Error saving ICO file [$TargetIconFilePath]"
}
Write-Host"Icon file can be found at [$TargetIconFilePath]"