70

以下代码引发 IOException 并显示以下消息:“指定的注册表项不存在。”

HttpClient client = new HttpClient();

Uri uri = new Uri("http://www.google.com");

client.GetAsync(uri);

这只是在 Main 的控制台应用程序中。看起来错误是由 mscorlib.dll!Microsoft.Win32.RegistryKey.Win32Error(int errorCode, string str) 引发的。我不知道为什么会抛出此错误或如何开始调试它。

编辑堆栈跟踪:

在 Microsoft.Win32.RegistryKey.Win32Error(Int32 错误代码,字符串 str)

它只是 1 行,没有内部异常等。

调用栈是:

mscorlib.dll!Microsoft.Win32.RegistryKey.Win32Error(int errorCode, string str) + 0x189 bytes    
mscorlib.dll!Microsoft.Win32.RegistryKey.GetValueKind(string name) + 0x7f bytes 
System.dll!System.Net.HybridWebProxyFinder.InitializeFallbackSettings() + 0x9e bytes    
[Native to Managed Transition]  
[Managed to Native Transition]  
System.dll!System.Net.AutoWebProxyScriptEngine.AutoWebProxyScriptEngine(System.Net.WebProxy proxy, bool useRegistry) + 0xd0 bytes   
System.dll!System.Net.WebProxy.UnsafeUpdateFromRegistry() + 0x2c bytes  
System.dll!System.Net.Configuration.DefaultProxySectionInternal.DefaultProxySectionInternal(System.Net.Configuration.DefaultProxySection section) + 0x1d8 bytes 
System.dll!System.Net.Configuration.DefaultProxySectionInternal.GetSection() + 0xec bytes   
System.dll!System.Net.WebRequest.InternalDefaultWebProxy.get() + 0xcc bytes 
System.dll!System.Net.HttpWebRequest.HttpWebRequest(System.Uri uri, System.Net.ServicePoint servicePoint) + 0xdf bytes  
System.dll!System.Net.HttpWebRequest.HttpWebRequest(System.Uri uri, bool returnResponseOnFailureStatusCode, string connectionGroupName, System.Action<System.IO.Stream> resendRequestContent) + 0x2b bytes  
System.Net.Http.dll!System.Net.Http.HttpClientHandler.CreateAndPrepareWebRequest(System.Net.Http.HttpRequestMessage request) + 0x59 bytes   
System.Net.Http.dll!System.Net.Http.HttpClientHandler.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) + 0xf4 bytes  
System.Net.Http.dll!System.Net.Http.HttpMessageInvoker.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) + 0x4f bytes 
System.Net.Http.dll!System.Net.Http.HttpClient.SendAsync(System.Net.Http.HttpRequestMessage request, System.Net.Http.HttpCompletionOption completionOption, System.Threading.CancellationToken cancellationToken) + 0x13e bytes 
System.Net.Http.dll!System.Net.Http.HttpClient.GetAsync(System.Uri requestUri, System.Net.Http.HttpCompletionOption completionOption) + 0xc bytes   

ConsoleServiceTest.exe!ConsoleServiceTest.Program.Main(string[] args) Line 20 + 0x17 bytes  C#
    [Native to Managed Transition]  
    [Managed to Native Transition]  
    Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() + 0x5a bytes  
    mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x285 bytes 
    mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x9 bytes   
    mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x57 bytes    
    mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x51 bytes   
    [Native to Managed Transition]  
4

3 回答 3

85

这似乎是由 .NET Framework 的最新安全更新引起的:MS12-074:.NET Framework 中的漏洞可能允许远程执行代码:2012 年 11 月 13 日 (KB 2745030)

这一切都归结为 Web 代理解析中的以下代码:

[RegistryPermission(SecurityAction.Assert, Read=@"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework")]
private static void InitializeFallbackSettings()
{
    allowFallback = false;
    try
    {
        using (RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\.NETFramework"))
        {
            try
            {
                if (key.GetValueKind("LegacyWPADSupport") == RegistryValueKind.DWord)
                {
                    allowFallback = ((int) key.GetValue("LegacyWPADSupport")) == 1;
                }
            }
            catch (UnauthorizedAccessException)
            {
            }
            catch (IOException)
            {
            }
        }
    }
    catch (SecurityException)
    {
    }
    catch (ObjectDisposedException)
    {
    }
}

如您所见,它会检查知识库文章中提到的特定注册表项。您还应该注意异常是在内部捕获的,但是您会看到它,因为您在 Visual Studio 的调试选项中启用了 First Chance Exceptions。

如果你不想看到这个异常,你应该添加指定的注册表键值0

Registry location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework  
DWORD (32-bit) Value name: LegacyWPADSupport
Value data: 0

对于 64 位机器上的 32 位进程:

Registry location: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework
DWORD (32-bit) Value name: LegacyWPADSupport
Value data: 0
于 2012-11-20T10:07:44.667 回答
28

我同意 Ligaz 的回答,并且我已经记录了有关此错误的 Connect 问题:https ://connect.microsoft.com/VisualStudio/feedback/details/773666/webrequest-create-eats-an-ioexception-on-the-第一次通话#详情

将以下内容保存到 .reg 文件中并将其导入注册表以防止出现此错误:

Windows Registry Editor Version 5.00

; The following value prevents an IOException from being thrown and caught
; by System.Net.HybridWebProxyFinder.InitializeFallbackSettings() (in System.dll)
; when WebRequest.Create is first called.  By default the "LegacyWPADSupport"
; value doesn't exist, and when InitializeFallbackSettings calls GetValueKind,
; an IOException is thrown.  This adds the value with its default of false to
; prevent the exception.
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework]
"LegacyWPADSupport"=dword:00000000

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework]
"LegacyWPADSupport"=dword:00000000
于 2012-12-06T14:24:55.617 回答
10

无论出于何种原因,您的HttpClient代码都在注册表中寻找代理设置并且无法打开密钥。查看代码显示它尝试打开 HKCU,然后按顺序转到以下键之一:

  1. "HKCU\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Connections"
  2. "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Connections"
  3. "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows\\CurrentVersion\\Internet Settings"

这三个之一可能是您的流程无法访问的关键,为什么我不确定。一种可能的解决方法是禁用自动检测代理设置。

否则,您需要弄清楚它正在加载的确切密钥,我们将分两步完成。

  1. 启用 System.Net 日志记录
  2. 下载并运行 Procmon,过滤应用程序的注册表访问,如下所示:
  1. 打开后,如果启用,则禁用捕获(放大镜应该有一个红色的 X)。在此处输入图像描述
  2. 开始过滤您的进程名称。在此处输入图像描述
  3. 取消选择除注册表项以外的所有选项

在此处输入图像描述

  1. 启用捕获(单击放大镜)
  2. 运行您的应用程序
  3. 在日志中找到有问题的条目,双击查看它打开的是哪个键

一旦确定了有问题的密钥,您就可以努力找出您的应用程序无权访问它的原因。也许,如果您的应用程序的名称有任何迹象,那么您的服务正在运行的用户帐户无法访问注册表项。

于 2012-10-30T15:32:47.410 回答