如何实现C#4.5控制台程序在3个文件上传完成后自动启动？

嗨，针对你遇到的“三个文件全部上传完成后才触发导入程序”的需求，我给你整理了两种靠谱的解决方案，都是基于你现有的技术栈（C# 4.5 + SQL Server 2014）来实现的：

方案一：改进FileSystemWatcher，添加延迟检查与文件完整性验证 #

FileSystemWatcher本身确实会在文件开始创建时就触发事件，但我们可以通过两个关键优化来解决问题：

• 延迟检查：给文件上传留足写入时间，避免触发时文件还在传输中
• 文件就绪验证：确认文件已经完全写入，无法被其他进程占用

核心实现步骤 #

1. 从app.config读取配置参数
2. 配置FileSystemWatcher监听目标文件夹的创建和大小变化事件
3. 事件触发后延迟几秒，再检查三个文件是否都存在且就绪
4. 满足条件时启动导入程序，完成后归档文件避免重复处理

代码示例 #

using System;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Diagnostics;

class AutoImportWatcher
{
    static void Main(string[] args)
    {
        var sourceFolder = ConfigurationManager.AppSettings["SourceFolder"];
        if (!Directory.Exists(sourceFolder))
        {
            Console.WriteLine($"Source folder {sourceFolder} does not exist!");
            return;
        }

        // 初始化文件监视器
        var watcher = new FileSystemWatcher(sourceFolder)
        {
            IncludeSubdirectories = false,
            NotifyFilter = NotifyFilters.FileName | NotifyFilters.Size // 监听文件名和大小变化
        };

        // 绑定事件
        watcher.Created += OnFileChanged;
        watcher.Changed += OnFileChanged;
        watcher.EnableRaisingEvents = true;

        Console.WriteLine($"Watching folder: {sourceFolder}");
        Console.WriteLine("Press Enter to exit...");
        Console.ReadLine();

        watcher.Dispose();
    }

    private static async void OnFileChanged(object sender, FileSystemEventArgs e)
    {
        // 延迟5秒，给文件上传留时间（可根据文件大小调整）
        await Task.Delay(TimeSpan.FromSeconds(5));
        CheckAndRunImport(sender);
    }

    private static void CheckAndRunImport(object sender)
    {
        var watcher = (FileSystemWatcher)sender;
        var sourceFolder = watcher.Path;
        var requiredFiles = new[]
        {
            ConfigurationManager.AppSettings["DisbursementFile"],
            ConfigurationManager.AppSettings["EmployeeFile"],
            ConfigurationManager.AppSettings["AmountFile"]
        };

        // 检查所有文件是否存在且已就绪
        bool allFilesReady = requiredFiles.All(file =>
        {
            string filePath = Path.Combine(sourceFolder, file);
            return File.Exists(filePath) && IsFileFullyUploaded(filePath);
        });

        if (allFilesReady)
        {
            // 临时关闭监视器，避免重复触发
            watcher.EnableRaisingEvents = false;

            try
            {
                Console.WriteLine("All files detected, starting import...");
                // 启动你的导入控制台程序
                Process.Start(@"Path\To\Your\ImportProgram.exe");

                // 归档文件，防止重复处理
                string archiveFolder = ConfigurationManager.AppSettings["ArchiveFolder"];
                if (!Directory.Exists(archiveFolder))
                    Directory.CreateDirectory(archiveFolder);

                foreach (var file in requiredFiles)
                {
                    string sourcePath = Path.Combine(sourceFolder, file);
                    string archivePath = Path.Combine(archiveFolder, $"{DateTime.Now:yyyyMMddHHmmss}_{file}");
                    File.Move(sourcePath, archivePath);
                    Console.WriteLine($"Archived file: {archivePath}");
                }

                // 记录日志
                WriteLog("Import completed successfully, files archived.");
            }
            catch (Exception ex)
            {
                WriteLog($"Import failed: {ex.Message}");
            }
            finally
            {
                // 重新开启监视器
                watcher.EnableRaisingEvents = true;
            }
        }
    }

    // 判断文件是否完全上传（能否被独占打开）
    private static bool IsFileFullyUploaded(string filePath)
    {
        try
        {
            using (var stream = File.Open(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
            {
                return true;
            }
        }
        catch (IOException)
        {
            // 文件被占用，说明还在上传
            return false;
        }
    }

    // 写入日志
    private static void WriteLog(string message)
    {
        string logPath = ConfigurationManager.AppSettings["LogFile"];
        string logEntry = $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}] {message}{Environment.NewLine}";
        File.AppendAllText(logPath, logEntry);
    }
}

方案二：定时扫描文件夹（更简单稳定的备选） #

如果觉得FileSystemWatcher的事件触发逻辑太敏感，可以用定时扫描的方式，每隔一段时间检查目标文件夹是否满足条件：

代码示例 #

using System;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Threading;
using System.Diagnostics;

class AutoImportScanner
{
    static void Main(string[] args)
    {
        var scanInterval = TimeSpan.FromMinutes(1); // 每分钟扫描一次，可调整
        var timer = new Timer(_ => CheckAndRunImport(), null, TimeSpan.Zero, scanInterval);

        Console.WriteLine("Auto import scanner started. Press Enter to exit...");
        Console.ReadLine();
        timer.Dispose();
    }

    private static void CheckAndRunImport()
    {
        var sourceFolder = ConfigurationManager.AppSettings["SourceFolder"];
        var requiredFiles = new[]
        {
            ConfigurationManager.AppSettings["DisbursementFile"],
            ConfigurationManager.AppSettings["EmployeeFile"],
            ConfigurationManager.AppSettings["AmountFile"]
        };

        bool allFilesReady = requiredFiles.All(file =>
        {
            string filePath = Path.Combine(sourceFolder, file);
            return File.Exists(filePath) && IsFileFullyUploaded(filePath);
        });

        if (allFilesReady)
        {
            try
            {
                Console.WriteLine("All files detected, starting import...");
                Process.Start(@"Path\To\Your\ImportProgram.exe");

                // 归档文件
                string archiveFolder = ConfigurationManager.AppSettings["ArchiveFolder"];
                if (!Directory.Exists(archiveFolder))
                    Directory.CreateDirectory(archiveFolder);

                foreach (var file in requiredFiles)
                {
                    string sourcePath = Path.Combine(sourceFolder, file);
                    string archivePath = Path.Combine(archiveFolder, $"{DateTime.Now:yyyyMMddHHmmss}_{file}");
                    File.Move(sourcePath, archivePath);
                }

                WriteLog("Import completed successfully.");
            }
            catch (Exception ex)
            {
                WriteLog($"Import error: {ex.Message}");
            }
        }
    }

    // 复用之前的IsFileFullyUploaded和WriteLog方法
    private static bool IsFileFullyUploaded(string filePath) 
    {
        try
        {
            using (var stream = File.Open(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
            {
                return true;
            }
        }
        catch (IOException)
        {
            return false;
        }
    }
    
    private static void WriteLog(string message)
    {
        string logPath = ConfigurationManager.AppSettings["LogFile"];
        string logEntry = $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}] {message}{Environment.NewLine}";
        File.AppendAllText(logPath, logEntry);
    }
}

关键注意事项 #

• 避免重复处理：一定要在导入完成后将文件移到Archive文件夹，或者重命名（比如加.processed后缀）
• 日志记录：严格记录每一步操作，方便后续排查问题
• 权限配置：确保运行自动程序的账户有目标文件夹的读写权限，以及启动导入程序的权限
• 延迟时间调整：如果你的文件很大，需要适当延长延迟时间，避免文件还在写入时就触发导入

内容的提问来源于stack exchange，提问作者Naweez