为什么 OpenSubKey() 在我的 Windows 10 64 位系统上返回 null？

Question

我正在开发 x86 应用程序以将自己创建的 "programming language" 转换为汇编程序。在某些时候，我需要获得 MASM32 的路径。我已经阅读了几个相关主题，但它们对我没有帮助，可能是因为我是 C# 的新手。 MASM32 位于此处：HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\MASM32。当我运行我的程序时，我总是收到 "Masm32 is not found" 消息。我应该怎么办？提前致谢！

WindowsIdentity ident = WindowsIdentity.GetCurrent();
        WindowsPrincipal myPrincipal = new WindowsPrincipal(ident);
        if (!myPrincipal.IsInRole(WindowsBuiltInRole.Administrator))
        {
            string user = Environment.UserDomainName + "\" + Environment.UserName;
            RegistrySecurity rs = new RegistrySecurity();
            rs.AddAccessRule(new RegistryAccessRule(user,
                        RegistryRights.ReadKey | RegistryRights.Delete | RegistryRights.CreateSubKey | RegistryRights.WriteKey | RegistryRights.ChangePermissions | RegistryRights.SetValue,
                        InheritanceFlags.None,
                        PropagationFlags.None,
                        AccessControlType.Deny));
        }
        try
        {
            RegistryKey baseKey = RegistryKey.OpenBaseKey(
            RegistryHive.LocalMachine,
            RegistryView.Registry64);
            RegistryKey key = baseKey.OpenSubKey(@"SOFTWARE\Wow6432Node\"); 
            PathMasm32 = baseKey.GetValue("MASM32").ToString();
        }
        catch {
            erTxt = "Masm32 is not found";
              }

Answer 1

可能不是 OpenSubKey() 导致空引用异常，而是 baseKey.GetValue().ToString() 调用。 baseKey.GetValue() returns null（因为在这种情况下，您正试图在 HKEY_LOCAL_MACHINE 根节点下获取一个值）并且您在 null 引用上调用 ToString()。而不是 baseKey.GetValue()，您应该尝试 key.GetValue()，假设 MASM32 确实是一个低于 HKLM\SOFTWARE\Wow6432Node 的值，这是极不可能的。

key.GetValue("MASM32").ToString();

安全注意事项：如果你正在寻找MASM32的安装路径，即使我没有这方面的专业知识，他们明确指出The MASM32 SDK is registry safe and writes nothing to the registry.

因此，MASM32 可能是一个 KEY 而不是一个 VALUE，因此请执行此方法并打印它的输出，假设它存在于注册表中，您将看到在 MASM32 键下注册的 key/value 对路径 HKLM\SOFTWARE\Wow6432Node\MASM32

public static string GetMASM32LocationFromRegistry()
{
    RegistryKey localMachineRegistryKey;
    RegistryKey masm32RegistryKey;
    RegistryView currentRegistryView = RegistryView.Registry64;

    localMachineRegistryKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, currentRegistryView);
    masm32RegistryKey = localMachineRegistryKey.OpenSubKey(@"SOFTWARE\Wow6432Node\MASM32");

    if (masm32RegistryKey == null)
    {
        return @"ERROR: The registry key HKLM\SOFTWARE\Wow6432Node\MASM32 could not be found";
    }

    StringBuilder masm32RegistryKeyValuesBuilder = new StringBuilder("Key/Value pairs for registry key HKLM\SOFTWARE\Wow6432Node\MASM32:\r\n");
    foreach (string masm32RegistryKeyValueName in masm32RegistryKey.GetValueNames())
    {
        masm32RegistryKeyValuesBuilder.AppendFormat
        (
            "Key: [{0}], Value: [{1}], Value Type: [{2}]\r\n",
            masm32RegistryKeyValueName,
            masm32RegistryKey.GetValue(masm32RegistryKeyValueName),
            masm32RegistryKey.GetValueKind(masm32RegistryKeyValueName)
        );
    }

    return masm32RegistryKeyValuesBuilder.ToString();
}

为什么 OpenSubKey() 在我的 Windows 10 64 位系统上返回 null？

Why is OpenSubKey() returning null on my Windows 10 64-bit system?

.net

c#

registry

64-bit