如何解决此 System.IO.FileNotFoundException

Question

• 该错误仅发生在生产中（不在调试中）。
• 该错误仅发生在 Windows 登录后第一个运行的应用程序上。
• 当我们单击 BtnUseDesktop 并因此触发 BtnUseDesktop_Click 事件时发生错误（如下）。
• 事件查看器堆栈以 The.Application.Name.Main() 方法开始...
• 但我们的代码没有该方法（它是一个 WPF 应用程序）。

事件查看器

 Application: The.Application.Name.exe
 Framework Version: v4.0.30319
 Description: The process was terminated due to an unhandled exception.
 Exception Info: System.IO.FileNotFoundException
 Stack:

   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(
      System.Object, System.Delegate, System.Object, Int32, System.Delegate)

   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(
      System.Windows.Threading.DispatcherPriority, System.TimeSpan, 
      System.Delegate, System.Object, Int32)

   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)

   at MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef)

   at System.Windows.Threading.Dispatcher.PushFrameImpl(
      System.Windows.Threading.DispatcherFrame)

   at System.Windows.Threading.Dispatcher.PushFrame(
      System.Windows.Threading.DispatcherFrame)

   at System.Windows.Threading.Dispatcher.Run()

   at System.Windows.Application.RunDispatcher(System.Object)

   at System.Windows.Application.RunInternal(System.Windows.Window)

   at System.Windows.Application.Run(System.Windows.Window)

   at The.Application.Name.Main()

BtnUseDesktop_Click

private void BtnUseDesktop_Click(object sender, RoutedEventArgs e)
{
    AvSwitcher switcher = new AvSwitcher();
    this.RunAsyncTask(() => 
        switcher.SwitchToDesktop(this.windowSyncSvc.ActiveLyncWindowHandle));
}

Click 事件调用的 AvSwitcher

public class AvSwitcher
{
    private DeviceLocationSvc deviceLocationSvc;
    private UIAutomationSvc uiAutomationSvc;
    private WindowMovingSvc windowMovingSvc;
    private ManualResetEvent manualResetEvent;
    private Modality audioVideo;
    public static bool IsSwitching { get; set; }

    public AvSwitcher()
    {            
        this.deviceLocationSvc = new DeviceLocationSvc();
        this.uiAutomationSvc = new UIAutomationSvc();
        this.windowMovingSvc = new WindowMovingSvc();
    }

    public void SwitchToDesktop(IntPtr activeLyncConvWindowHandle)
    {
        this.BeginHold(DeviceLocation.Desktop, activeLyncConvWindowHandle);
    }

    public void SwitchToWall(IntPtr activeLyncConvWindowHandle)
    {
        this.BeginHold(DeviceLocation.Wall, activeLyncConvWindowHandle);
    }

    private Conversation GetLyncConversation()
    {
        Conversation conv = null;
        if (LyncClient.GetClient() != null)
        {
            conv = LyncClient.GetClient().ConversationManager.Conversations.FirstOrDefault();
        }

        return conv;
    }

    private void BeginHold(DeviceLocation targetLocation, IntPtr activeLyncConvWindowHandle)
    {
        AvSwitcher.IsSwitching = true;

        // make sure the class doesn't dispose of itself
        this.manualResetEvent = new ManualResetEvent(false);

        Conversation conv = this.GetLyncConversation();
        if (conv != null)
        {
            this.audioVideo = conv.Modalities[ModalityTypes.AudioVideo];
            ModalityState modalityState = this.audioVideo.State;

            if (modalityState == ModalityState.Connected)
            {
                this.HoldCallAndThenDoTheSwitching(targetLocation, activeLyncConvWindowHandle);
            }
            else
            {
                this.DoTheSwitching(targetLocation, activeLyncConvWindowHandle);
            }
        }
    }

    private void HoldCallAndThenDoTheSwitching(
        DeviceLocation targetLocation, 
        IntPtr activeLyncConvWindowHandle)
    {
        try
        {
            this.audioVideo.BeginHold(
                this.BeginHold_callback,
                new AsyncStateValues()
                {
                    TargetLocation = targetLocation,
                    ActiveLyncConvWindowHandle = activeLyncConvWindowHandle
                });
            this.manualResetEvent.WaitOne();
        }
        catch (UnauthorizedAccessException)
        {
            // the call is already on hold
            this.DoTheSwitching(targetLocation, activeLyncConvWindowHandle);
        }
    }

    private void BeginHold_callback(IAsyncResult ar)
    {
        if (ar.IsCompleted)
        {
            DeviceLocation targetLocation = ((AsyncStateValues)ar.AsyncState).TargetLocation;
            IntPtr activeLyncConvWindowHandle = 
                ((AsyncStateValues)ar.AsyncState).ActiveLyncConvWindowHandle;
            this.DoTheSwitching(targetLocation, activeLyncConvWindowHandle);
        }

        Thread.Sleep(2000); // is this necessary
        this.audioVideo.BeginRetrieve(this.BeginRetrieve_callback, null);
    }

    private void DoTheSwitching(DeviceLocation targetLocation, IntPtr activeLyncConvWindowHandle)
    {
        DeviceLocationSvc.TargetDevices targetDevices = 
            this.deviceLocationSvc.GetTargetDevices(targetLocation);

        this.SwitchScreenUsingWinApi(targetDevices.Screen, activeLyncConvWindowHandle);
        this.SwitchVideoUsingLyncApi(targetDevices.VideoDevice);
        this.SwitchAudioUsingUIAutomation(
            targetDevices.MicName, 
            targetDevices.SpeakersName, 
            activeLyncConvWindowHandle);

        AvSwitcher.IsSwitching = false;
    }

    private void SwitchScreenUsingWinApi(Screen targetScreen, IntPtr activeLyncConvWindowHandle)
    {
        if (activeLyncConvWindowHandle != IntPtr.Zero)
        {
            WindowPosition wp = 
                this.windowMovingSvc.GetTargetWindowPositionFromScreen(targetScreen);
            this.windowMovingSvc.MoveTheWindowToTargetPosition(activeLyncConvWindowHandle, wp);
        }
    }

    private void SwitchVideoUsingLyncApi(VideoDevice targetVideoDevice)
    {
        if (targetVideoDevice != null)
        {
            LyncClient.GetClient().DeviceManager.ActiveVideoDevice = targetVideoDevice;
        }
    }

    private void SwitchAudioUsingUIAutomation(
        string targetMicName, 
        string targetSpeakersName, 
        IntPtr activeLyncConvWindowHandle)
    {
        if (targetMicName != null && targetSpeakersName != null)
        {
            AutomationElement lyncConvWindow = 
                AutomationElement.FromHandle(activeLyncConvWindowHandle);

            AutomationElement lyncOptionsWindow =
                this.uiAutomationSvc.OpenTheLyncOptionsWindowFromTheConvWindow(lyncConvWindow);

            this.uiAutomationSvc.SelectTheTargetMic(lyncOptionsWindow, targetMicName);

            this.uiAutomationSvc.SelectTheTargetSpeakers(lyncOptionsWindow, targetSpeakersName);

            this.uiAutomationSvc.InvokeOkayButton(lyncOptionsWindow);
        }
    }

    private void BeginRetrieve_callback(IAsyncResult ar)
    {
        this.audioVideo.EndRetrieve(ar);
        this.manualResetEvent.Set(); // allow the program to exit
    }

    private class AsyncStateValues
    {
        internal DeviceLocation TargetLocation { get; set; }

        internal IntPtr ActiveLyncConvWindowHandle { get; set; }
    }
}

Answer 1

我不想指出明显的问题，但System.IO.FileNotFoundException 表示程序没有找到您指定的文件。所以你需要做的是检查你的代码在生产中寻找什么文件。

要查看您的程序在生产环境中查找的文件（查看异常的 FileName 属性），请尝试以下技术：

• 写入调试日志，
• 使用Visual Studio Attach to Process，或
• 使用Visual Studio Remote Debugging

然后查看机器上的文件系统，看看文件是否存在。最有可能的情况是它不存在。

Answer 2

我在发布 ClickOnce 应用程序后遇到了类似情况，我在不同域的一位同事报告说它无法启动。

为了了解发生了什么，我在 MainWindow 方法中添加了一条 try catch 语句，正如@BradleyDotNET 在原始帖子的一条评论中提到的那样，然后再次发布。

public MainWindow()
{
    try
    {
        InitializeComponent();
    }
    catch (Exception exc)
    {
        MessageBox.Show(exc.ToString());
    }
}

然后我的同事向我报告了异常细节，这是缺少第三方框架dll文件的引用。

添加参考并解决问题。

Answer 3

我不止一次被这个错误误导。在花费数小时谷歌搜索、更新 nuget 包、版本检查之后，在使用完全更新的解决方案之后，我重新意识到了一个完全有效、更简单的错误原因。

如果在线程化进程中（例如 UI Dispatcher.Invoke），如果线程管理器 dll（文件）无法返回，则会引发 System.IO.FileNotFoundException。因此，如果您的主 UI 线程 A 调用系统线程管理器 dll B，而 B 调用您的线程代码 C，但 C 因某些不相关的原因抛出（例如在我的情况下为 null 引用），则 C 不会返回，B 会不返回，A只用FileNotFoundException责怪B丢失了……

在进入 dll 版本路径之前...检查离家较近的地方并验证您的线程代码没有抛出。

Answer 4

仔细检查所有参考文献

• 目标机器和本地机器上的版本保持不变
• 如果从 GAC 引用程序集，请确保加载正确的版本

对我来说，通过手动删除来清理整个解决方案，使用与目标计算机同步的版本再次更新（删除和添加）引用，然后使用 Copy Local > False for GAC 程序集进行构建可以解决问题。