[PowerShell]用PowerShell設定proxy

參考網址：https://github.com/majkinetor/posh/blob/master/MM_Network/Update-Proxy.ps1

# Author: Miodrag Milic <miodrag.milic@gmail.com>
# Last Change: 14-Aug-2015.

#requires -version 2.0

<#
.SYNOPSIS
    Get or set system proxy properties.
.DESCRIPTION
    This function implements unified method to set proxy system wide settings.
    It sets both WinINET ("Internet Options" proxy) and WinHTTP proxy.
    Without any arguments function will return the current proxy properties.
    To change a proxy property pass adequate argument to the function.
.EXAMPLE
    Update-Proxy -Server "myproxy.mydomain.com:8080" -Override "" -ShowGUI
    Set proxy server, clear overrides and show IE GUI.
.EXAMPLE
    Update-Proxy | Export-CSV proxy;  Import-CSV proxy | Update-Proxy -Verbose
    Save and restore proxy properties
.EXAMPLE
    $p = Update-Proxy; $p.Override += $p.Override += "*.domain.com" ; $p | proxy
    Add "*.domain.com" to the proxy override list
.NOTES
    The format of the parameters is the same as seen in Internet Options GUI.
    To bypass proxy for a local network specify keyword ";<local>" at the end
    of the Overide values.
    Setting the winhttp proxy requires administrative prvilegies.
.OUTPUTS
    [HashTable]
#>
function Update-Proxy() {
    [CmdletBinding()]
    param(
        # Proxy:Port
        [Parameter(ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true)]
        [string] $Server,
        # Semicollon delimited list of exlusions
        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [string] $Override,
        # 0 to disable, anything else to enable proxy
        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [string] $Enable,
        # Show Internet Options GUI
        [switch] $ShowGUI
    )
    $key  = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings"
    $r = gp $key
    Write-Verbose "Reading proxy data from the registry"
    $proxy=@{
            Server   = if ($PSBoundParameters.Keys -contains 'Server')   {$Server}   else { $r.ProxyServer }
            Override = if ($PSBoundParameters.Keys -contains 'Override') {$Override} else { $r.ProxyOverride }
            Enable   = if ($PSBoundParameters.Keys -contains 'Enable')   {$Enable}   else { $r.ProxyEnable }
    }

    $set  = "Server","Override","Enable" | ? {$PSBoundParameters.Keys -contains $_ }
    if ($set) {
        #if (!(test-admin)) { throw "Setting proxy requires admin privileges" }

        Write-Verbose "Saving proxy data to registry"

        sp $key ProxyServer   $proxy.Server
        sp $key ProxyOverride $proxy.Override
        sp $key ProxyEnable   $proxy.Enable
        if (!(refresh-system)) { Write-Warning "Can not force system refresh after proxy change" }

        Write-Verbose "Importing winhttp proxy from IE settings"
        $OFS = "`n"
        [string]$res = netsh.exe winhttp import proxy source=ie
        if ($res -match 'Access is denied') {Write-Warning $res}
        else { Write-Verbose $res.Trim()}
    }

    New-Object PSCustomObject -Property $proxy
    if ($ShowGUI) { start control "inetcpl.cpl,,4" }
}

# The registry changes aren't seen until system is notified about it.
# Without this function you need to open Internet Settings window for changes to take effect. See http://goo.gl/OIQ4W4
function refresh-system() {
    $signature = @'
[DllImport("wininet.dll", SetLastError = true, CharSet=CharSet.Auto)]
public static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int dwBufferLength);
'@

    $INTERNET_OPTION_SETTINGS_CHANGED   = 39
    $INTERNET_OPTION_REFRESH            = 37
    $type = Add-Type -MemberDefinition $signature -Name wininet -Namespace pinvoke -PassThru
    $a = $type::InternetSetOption(0, $INTERNET_OPTION_SETTINGS_CHANGED, 0, 0)
    $b = $type::InternetSetOption(0, $INTERNET_OPTION_REFRESH, 0, 0)
    return $a -and $b
}

Set-Alias proxy Update-Proxy