如何在ICommandPredictor中获取调用预测器的Shell当前目录？

直接通过PowerShell的Runspace会话状态获取当前工作目录即可——Environment.CurrentDirectory和Directory.GetCurrentDirectory()返回的是进程启动目录，而PowerShell的工作目录是会话级状态，由Runspace单独维护。

具体实现步骤 #

• 在PredictSuggestionsAsync方法中，通过Runspace.DefaultRunspace获取当前会话的Runspace实例
• 利用Runspace的SessionStateProxy.Path.CurrentLocation.Path拿到当前Shell的工作目录
• 基于该目录查询Git分支列表，再转为预测建议返回

代码示例 #

using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Management.Automation.Subsystem;
using System.Management.Automation.Subsystem.Prediction;

public class GitBranchPredictor : ICommandPredictor
{
    public string Name => "GitBranchPredictor";
    public Guid Id => new Guid("你的预测器唯一GUID");

    public async Task<PredictorPredictionResult> PredictSuggestionsAsync(PredictorCommandPredictionContext context, CancellationToken cancellationToken)
    {
        // 获取当前Runspace实例
        var runspace = Runspace.DefaultRunspace;
        if (runspace == null)
        {
            return PredictorPredictionResult.NoSuggestions;
        }

        // 获取当前Shell的工作目录
        string currentWorkingDir = runspace.SessionStateProxy.Path.CurrentLocation.Path;

        // 查询当前目录下的Git本地分支
        var gitBranches = GetLocalGitBranches(currentWorkingDir);

        // 转换为PowerShell命令建议格式
        var suggestions = gitBranches.Select(branch => new CommandSuggestion(branch)).ToList();
        return new PredictorPredictionResult(suggestions);
    }

    private List<string> GetLocalGitBranches(string directory)
    {
        var branchList = new List<string>();
        try
        {
            var startInfo = new ProcessStartInfo
            {
                FileName = "git",
                Arguments = "branch --list",
                WorkingDirectory = directory,
                RedirectStandardOutput = true,
                UseShellExecute = false,
                CreateNoWindow = true
            };

            using var process = Process.Start(startInfo);
            if (process == null) return branchList;

            string output = process.StandardOutput.ReadToEnd();
            process.WaitForExit();

            // 解析Git分支输出，去除前缀的*和空格
            branchList = output.Split(new[] { '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries)
                               .Select(line => line.TrimStart('*', ' '))
                               .ToList();
        }
        catch
        {
            // 处理Git未安装、当前目录不是Git仓库等异常情况
        }
        return branchList;
    }

    // 实现ICommandPredictor接口的其他必要方法
    public void OnCommandLineAccepted(string commandLine) { }
    public void OnCommandLineExecuted(string commandLine) { }
    public void OnSessionStateChanged(SessionStateChangedEventArgs args) { }
    public bool CanAcceptFeedback(PredictionFeedbackKind feedback) => false;
    public void OnSuggestionAccepted(SuggestionAcceptedFeedback feedback) { }
    public void OnCommandLinePredictionFeedback(CommandLinePredictionFeedback feedback) { }
}

关键说明 #

• Runspace是PowerShell的会话容器，每个会话的工作目录独立维护，通过SessionStateProxy可直接访问会话级状态信息
• 若想避免依赖外部Git命令，也可以使用LibGit2Sharp库直接操作Git仓库，代码会更简洁可控

内容的提问来源于stack exchange，提问作者Ashijo