编写 C# cmdlet 时接收文件作为参数的正确方法是什么？ 到目前为止，我只有一个属性 LiteralPath （与它们的参数命名约定一致），它是一个字符串。这是一个问题，因为你只能得到在控制台中输入的任何内容；这可以是完整路径，也可以是相对路径。
使用 Path.GetFullPath(string) 不起作用。它认为我目前处于〜，但我不是。 如果我将属性从字符串更改为 FileInfo，也会出现同样的问题。
编辑：对于任何感兴趣的人，此解决方法对我有用：
SessionState ss = new SessionState();
Directory.SetCurrentDirectory(ss.Path.CurrentFileSystemLocation.Path);
LiteralPath = Path.GetFullPath(LiteralPath);
LiteralPath 是字符串参数。 我仍然有兴趣了解处理作为参数传递的文件路径的推荐方法。
EDIT2：这样更好，这样你就不会弄乱用户当前目录，你应该将其设置回来。
string current = Directory.GetCurrentDirectory();
Directory.SetCurrentDirectory(ss.Path.CurrentFileSystemLocation.Path);
LiteralPath = Path.GetFullPath(LiteralPath);
Directory.SetCurrentDirectory(current);
这是一个极其复杂的领域，但我在这里有丰富的经验。简而言之，有一些 cmdlet 直接从 System.IO API 接受 win32 路径，并且这些 cmdlet 通常使用 -FilePath 参数。如果您想编写一个行为良好的“powershelly”cmdlet，则需要 -Path 和 -LiteralPath，以接受管道输入并使用相对和绝对提供程序路径。这是我不久前写的博客文章的摘录：
PowerShell 中的路径[一开始很难理解。] PowerShell 路径 - 或 PSPaths，不要与 Win32 路径混淆 - 在其绝对形式中，它们有两种不同的风格：
FileSystem::c:\temp\foo.txtc:\temp\foo.txt很容易混淆提供者内部（已解析的
ProviderPathSystem.Management.Automation.PathInfo::ps c:\> new-psdrive temp filesystem c:\temp\
ps c:\> cd temp:
ps temp:\>
现在，让我们再看一下：
FileSystem::c:\temp\foo.txttemp:\foo.txt这次更容易看到这次有什么不同。提供商名称右侧的粗体文本是 ProviderPath。
因此，编写接受路径的通用提供者友好的 Cmdlet（或高级函数）的目标是：
LiteralPath的
PSPathPath第三点尤其重要。另外，显然
LiteralPathPath相对路径
一个好问题是：我们如何处理传递给 Cmdlet 的相对路径。由于您应该假设提供给您的所有路径都是 PSPath，所以让我们看看下面的 Cmdlet 的作用：
ps temp:\> write-zip -literalpath foo.txt
该命令应假设 foo.txt 位于当前驱动器中，因此应立即在 ProcessRecord 或 EndProcessing 块中解决此问题，例如（使用此处的脚本 API 进行演示）：
$provider = $null;
$drive = $null
$pathHelper = $ExecutionContext.SessionState.Path
$providerPath = $pathHelper.GetUnresolvedProviderPathFromPSPath(
"foo.txt", [ref]$provider, [ref]$drive)
现在您已拥有重新创建 PSPath 的两种绝对形式所需的一切，并且您还拥有本机绝对 ProviderPath。要为 foo.txt 创建提供者限定的 PSPath，请使用
$provider.Name + “::” + $providerPath$drive$null$drive$null$drive.name + ":\" + $drive.CurrentLocation + "\" + "foo.txt"快速入门 C# 骨架
这里有一个 C# 提供程序感知 cmdlet 的框架，可以帮助您入门。它内置了检查，以确保它已获得文件系统提供程序路径。我正在为 NuGet 打包它，以帮助其他人编写行为良好的提供者感知 Cmdlet：
using System;
using System.Collections.Generic;
using System.IO;
using System.Management.Automation;
using Microsoft.PowerShell.Commands;
namespace PSQuickStart
{
[Cmdlet(VerbsCommon.Get, Noun,
DefaultParameterSetName = ParamSetPath,
SupportsShouldProcess = true)
]
public class GetFileMetadataCommand : PSCmdlet
{
private const string Noun = "FileMetadata";
private const string ParamSetLiteral = "Literal";
private const string ParamSetPath = "Path";
private string[] _paths;
private bool _shouldExpandWildcards;
[Parameter(
Mandatory = true,
ValueFromPipeline = false,
ValueFromPipelineByPropertyName = true,
ParameterSetName = ParamSetLiteral)
]
[Alias("PSPath")]
[ValidateNotNullOrEmpty]
public string[] LiteralPath
{
get { return _paths; }
set { _paths = value; }
}
[Parameter(
Position = 0,
Mandatory = true,
ValueFromPipeline = true,
ValueFromPipelineByPropertyName = true,
ParameterSetName = ParamSetPath)
]
[ValidateNotNullOrEmpty]
public string[] Path
{
get { return _paths; }
set
{
_shouldExpandWildcards = true;
_paths = value;
}
}
protected override void ProcessRecord()
{
foreach (string path in _paths)
{
// This will hold information about the provider containing
// the items that this path string might resolve to.
ProviderInfo provider;
// This will be used by the method that processes literal paths
PSDriveInfo drive;
// this contains the paths to process for this iteration of the
// loop to resolve and optionally expand wildcards.
List<string> filePaths = new List<string>();
if (_shouldExpandWildcards)
{
// Turn *.txt into foo.txt,foo2.txt etc.
// if path is just "foo.txt," it will return unchanged.
filePaths.AddRange(this.GetResolvedProviderPathFromPSPath(path, out provider));
}
else
{
// no wildcards, so don't try to expand any * or ? symbols.
filePaths.Add(this.SessionState.Path.GetUnresolvedProviderPathFromPSPath(
path, out provider, out drive));
}
// ensure that this path (or set of paths after wildcard expansion)
// is on the filesystem. A wildcard can never expand to span multiple
// providers.
if (IsFileSystemPath(provider, path) == false)
{
// no, so skip to next path in _paths.
continue;
}
// at this point, we have a list of paths on the filesystem.
foreach (string filePath in filePaths)
{
PSObject custom;
// If -whatif was supplied, do not perform the actions
// inside this "if" statement; only show the message.
//
// This block also supports the -confirm switch, where
// you will be asked if you want to perform the action
// "get metadata" on target: foo.txt
if (ShouldProcess(filePath, "Get Metadata"))
{
if (Directory.Exists(filePath))
{
custom = GetDirectoryCustomObject(new DirectoryInfo(filePath));
}
else
{
custom = GetFileCustomObject(new FileInfo(filePath));
}
WriteObject(custom);
}
}
}
}
private PSObject GetFileCustomObject(FileInfo file)
{
// this message will be shown if the -verbose switch is given
WriteVerbose("GetFileCustomObject " + file);
// create a custom object with a few properties
PSObject custom = new PSObject();
custom.Properties.Add(new PSNoteProperty("Size", file.Length));
custom.Properties.Add(new PSNoteProperty("Name", file.Name));
custom.Properties.Add(new PSNoteProperty("Extension", file.Extension));
return custom;
}
private PSObject GetDirectoryCustomObject(DirectoryInfo dir)
{
// this message will be shown if the -verbose switch is given
WriteVerbose("GetDirectoryCustomObject " + dir);
// create a custom object with a few properties
PSObject custom = new PSObject();
int files = dir.GetFiles().Length;
int subdirs = dir.GetDirectories().Length;
custom.Properties.Add(new PSNoteProperty("Files", files));
custom.Properties.Add(new PSNoteProperty("Subdirectories", subdirs));
custom.Properties.Add(new PSNoteProperty("Name", dir.Name));
return custom;
}
private bool IsFileSystemPath(ProviderInfo provider, string path)
{
bool isFileSystem = true;
// check that this provider is the filesystem
if (provider.ImplementingType != typeof(FileSystemProvider))
{
// create a .NET exception wrapping our error text
ArgumentException ex = new ArgumentException(path +
" does not resolve to a path on the FileSystem provider.");
// wrap this in a powershell errorrecord
ErrorRecord error = new ErrorRecord(ex, "InvalidProvider",
ErrorCategory.InvalidArgument, path);
// write a non-terminating error to pipeline
this.WriteError(error);
// tell our caller that the item was not on the filesystem
isFileSystem = false;
}
return isFileSystem;
}
}
}
Cmdlet 开发指南 (Microsoft)
以下是一些更通用的建议，从长远来看应该对您有所帮助： https://learn.microsoft.com/en-us/powershell/scripting/developer/cmdlet/strongly-encouraging-development-guidelines?view=powershell-7.4#support-windows-powershell-paths