Question

我有我的自定义函数 f ，该函数运行一些东西，然后调用预定义的函数 Invoke-WebRequest

我想让 f 接受 Invoke-WebRequest 的所有参数，然后将这些参数传递给 Invoke-WebRequest 。 / p>

 f --UseBasicParsing -Uri https://google.com -UseBasicParsing  -Body @{'name'='user'} -ErrorOnAction Stop
 # Some processing is made
 # then, the following is executed
 Invoke-WebRequest -Uri https://google.com -UseBasicParsing -Body @{'name'='user'} -ErrorOnAction Stop

有没有一种快速的方法来实现这一目标？（而不是在 f 中声明所有可能的参数）

Answer 1

尽管它与不声明参数不同，但是您可以通过生成代理命令来生成声明：

[System.Management.Automation.ProxyCommand]::Create((Get-Command Invoke-WebRequest))

结果将如下所示：

[CmdletBinding(HelpUri='https://go.microsoft.com/fwlink/?LinkID=217035')]
param(
    [switch]
    ${UseBasicParsing},

    [Parameter(Mandatory=$true, Position=0)]
    [ValidateNotNullOrEmpty()]
    [uri]
    ${Uri},

    [Microsoft.PowerShell.Commands.WebRequestSession]
    ${WebSession},

    [Alias('SV')]
    [string]
    ${SessionVariable},

    [pscredential]
    [System.Management.Automation.CredentialAttribute()]
    ${Credential},

    [switch]
    ${UseDefaultCredentials},

    [ValidateNotNullOrEmpty()]
    [string]
    ${CertificateThumbprint},

    [ValidateNotNull()]
    [X509Certificate]
    ${Certificate},

    [string]
    ${UserAgent},

    [switch]
    ${DisableKeepAlive},

    [ValidateRange(0, 2147483647)]
    [int]
    ${TimeoutSec},

    [System.Collections.IDictionary]
    ${Headers},

    [ValidateRange(0, 2147483647)]
    [int]
    ${MaximumRedirection},

    [Microsoft.PowerShell.Commands.WebRequestMethod]
    ${Method},

    [uri]
    ${Proxy},

    [pscredential]
    [System.Management.Automation.CredentialAttribute()]
    ${ProxyCredential},

    [switch]
    ${ProxyUseDefaultCredentials},

    [Parameter(ValueFromPipeline=$true)]
    [System.Object]
    ${Body},

    [string]
    ${ContentType},

    [ValidateSet('chunked','compress','deflate','gzip','identity')]
    [string]
    ${TransferEncoding},

    [string]
    ${InFile},

    [string]
    ${OutFile},

    [switch]
    ${PassThru})

begin
{
    try {
        $outBuffer = $null
        if ($PSBoundParameters.TryGetValue('OutBuffer', [ref]$outBuffer))
        {
            $PSBoundParameters['OutBuffer'] = 1
        }
        $wrappedCmd = $ExecutionContext.InvokeCommand.GetCommand('Microsoft.PowerShell.Utility\Invoke-WebRequest', [System.Management.Automation.CommandTypes]::Cmdlet)
        $scriptCmd = {& $wrappedCmd @PSBoundParameters }
        $steppablePipeline = $scriptCmd.GetSteppablePipeline($myInvocation.CommandOrigin)
        $steppablePipeline.Begin($PSCmdlet)
    } catch {
        throw
    }
}

process
{
    try {
        $steppablePipeline.Process($_)
    } catch {
        throw
    }
}

end
{
    try {
        $steppablePipeline.End()
    } catch {
        throw
    }
}
<#

.ForwardHelpTargetName Microsoft.PowerShell.Utility\Invoke-WebRequest
.ForwardHelpCategory Cmdlet

#>

Answer 2

如果您不需要预先验证参数，最简单的方法是将所有参数（反映在自动变量$Args中）通过splatting传递，即作为@Args ：

function f { Invoke-WebRequest @Args }

请注意此方法的局限性：

您的函数不能为advanced (cmdlet-like) function，因为此类函数拒绝接受未绑定到声明的参数的参数。
虽然可以在声明参数的同时仍使函数不高级（以便声明特定于f的参数，这些参数不应反映在$Args中），{{ 3}}，即使没有显式的[CmdletBinding([...])]属性。

如果您确实需要提高功能，最好的选择是创建一个代理功能，如use of a [Parameter(...)] attribute implicitly makes your function an advanced one中所述，该代理功能通过自动将绑定到声明的参数的值传递给$PSBoundParameters变量。

在Powershell中实现装饰器模式

2 个答案: