如何使用C#检查注册表值是否存在？

如何通过C代码检查注册表值是否存在？ 这是我的代码，我想检查“开始”是否存在

public static bool checkMachineType()
{
    RegistryKey winLogonKey = Registry.LocalMachine.OpenSubKey(@"System\CurrentControlSet\services\pcmcia", true);
    string currentKey= winLogonKey.GetValue("Start").ToString();

    if (currentKey == "0")
        return (false);
    return (true);
}

---

对于注册表项，您可以在获取注册表项后检查它是否为空。如果它不存在，它就会存在

对于注册表值，可以获取当前项的值名称，并检查此数组是否包含所需的值名称

例如：

public static bool checkMachineType()
{    
    RegistryKey winLogonKey = Registry.LocalMachine.OpenSubKey(@"System\CurrentControlSet\services\pcmcia", true);
    return (winLogonKey.GetValueNames().Contains("Start"));
}

此简单函数仅在找到值但该值不为null时返回true，如果该值存在但为null或该值在键中不存在，则将返回false

---

问题的用法：

if (ValueExists(winLogonKey, "Start")
{
    // The values exists
}
else
{
    // The values does not exists
}

当然，“法格纳·安图内斯·多内尔斯”的回答是正确的。但在我看来，另外还值得检查注册表分支本身，或者确保该部分确实存在

例如（“脏黑客”），我需要在RMS基础设施中建立信任，否则当我打开Word或Excel文档时，将提示我输入“Active Directory权限管理服务”。下面是我如何在企业基础架构中为我的服务器添加远程信任的方法

foreach (var strServer in listServer)
{
    try
    {
        RegistryKey regCurrentUser = Registry.CurrentUser.OpenSubKey($"Software\\Classes\\Local Settings\\Software\\Microsoft\\MSIPC\\{strServer}", false);
        if (regCurrentUser == null)
            throw new ApplicationException("Not found registry SubKey ...");
        if (regCurrentUser.GetValueNames().Contains("UserConsent") == false)
            throw new ApplicationException("Not found value in SubKey ...");
    }
    catch (ApplicationException appEx)
    {
        Console.WriteLine(appEx);
        try
        {
            RegistryKey regCurrentUser = Registry.CurrentUser.OpenSubKey($"Software\\Classes\\Local Settings\\Software\\Microsoft\\MSIPC", true);
            RegistryKey newKey = regCurrentUser.CreateSubKey(strServer, true);
            newKey.SetValue("UserConsent", 1, RegistryValueKind.DWord);
        }
        catch(Exception ex)
        {
            Console.WriteLine($"{ex} Pipec kakoito ...");
        }
    }
}

---

@hsanders即使问题已经回答了，也欢迎添加有用的信息。堆栈溢出接收来自Google的大量流量；）root.GetValue（valueName）！=如果valueName不存在，null将引发异常。是否应更改为返回根？.GetValue（valueName）！=无效的如果valueName不存在，GetValue会引发哪个异常？后者的例子，因为这就是问题的问题所在？我不相信这是公认的答案。其他解决方案是检查键是否存在。对于value，我们必须检查该键中的值列表

GetValue

的返回类型永远不会是

RegistryKey

类型，那么为什么要强制转换它呢？

  RegistryKey rkSubKey = Registry.CurrentUser.OpenSubKey(" Your Registry Key Location", false);
        if (rkSubKey == null)
        {
           // It doesn't exist
        }
        else
        {
           // It exists and do something if you want to
         }

        internal static Func<string, string, bool> regKey = delegate (string KeyLocation, string Value)
        {
            // get registry key with Microsoft.Win32.Registrys
            RegistryKey rk = (RegistryKey)Registry.GetValue(KeyLocation, Value, null); // KeyLocation and Value variables from method, null object because no default value is present. Must be casted to RegistryKey because method returns object.
            if ((rk) == null) // if the RegistryKey is null which means it does not exist
            {
                // the key does not exist
                return false; // return false because it does not exist
            }
            // the registry key does exist
            return true; // return true because it does exist
        };

        // usage:
        /* Create Key - while (loading)
        {
            RegistryKey k;
            k = Registry.CurrentUser.CreateSubKey("stuff");
            k.SetValue("value", "value");
            Thread.Sleep(int.MaxValue);
        }; // no need to k.close because exiting control */


        if (regKey(@"HKEY_CURRENT_USER\stuff  ...  ", "value"))
        {
             // key exists
             return;
        }
        // key does not exist

public bool ValueExists(RegistryKey Key, string Value)
{
   try
   {
       return Key.GetValue(Value) != null;
   }
   catch
   {
       return false;
   }
}

if (ValueExists(winLogonKey, "Start")
{
    // The values exists
}
else
{
    // The values does not exists
}

foreach (var strServer in listServer)
{
    try
    {
        RegistryKey regCurrentUser = Registry.CurrentUser.OpenSubKey($"Software\\Classes\\Local Settings\\Software\\Microsoft\\MSIPC\\{strServer}", false);
        if (regCurrentUser == null)
            throw new ApplicationException("Not found registry SubKey ...");
        if (regCurrentUser.GetValueNames().Contains("UserConsent") == false)
            throw new ApplicationException("Not found value in SubKey ...");
    }
    catch (ApplicationException appEx)
    {
        Console.WriteLine(appEx);
        try
        {
            RegistryKey regCurrentUser = Registry.CurrentUser.OpenSubKey($"Software\\Classes\\Local Settings\\Software\\Microsoft\\MSIPC", true);
            RegistryKey newKey = regCurrentUser.CreateSubKey(strServer, true);
            newKey.SetValue("UserConsent", 1, RegistryValueKind.DWord);
        }
        catch(Exception ex)
        {
            Console.WriteLine($"{ex} Pipec kakoito ...");
        }
    }
}