这不是你问题的完整答案，但这里有一大块是我花了几个小时手工编译的。它是每个布局代码与我的Windows 7版本可用的布局名称的Map。我不得不手工输入名称，所以请原谅这里的任何打字错误。代码是通过编程收集的。

using System;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Input;

namespace DesktopDictation.DeviceButtonMappings
{
  public class KeyboardLayout
  {
    const int KL_NAMELENGTH = 9;

    [DllImport("user32.dll")]
    private static extern long GetKeyboardLayoutName(StringBuilder pwszKLID); 

    //each keyboard layout is defined in Windows as a hex code
    public static string GetLayoutCode()
    {
      var name = new StringBuilder(KL_NAMELENGTH);
      GetKeyboardLayoutName(name);

      return name.ToString();
    }

    //This is a mapping table from hex to descriptive name
    public static String MapLayoutName(string code = null)
    {
      if (code == null)
        code = GetLayoutCode();

      switch (code)
      {
        case "0000041C":
          return "Albanian";
        case "00000401":
          return "Arabic (101)";
        case "00010401":
          return "Arabic (102)";
        case "00020401":
          return "Arabic (102) Azerty";
        case "0000042B":
          return "Armenian eastern";
        case "0001042B":
          return "Armenian Western";
        case "0000044D":
          return "Assamese - inscript";
        case "0000082C":
          return "Azeri Cyrillic";
        case "0000042C":
          return "Azeri Latin";
        case "0000046D":
          return "Bashkir";
        case "00000423":
          return "Belarusian";
        case "0000080C":
          return "Belgian French";
        case "00000813":
          return "Belgian (period)";
        case "0001080C":
          return "Belgian (comma)";
        case "00000445":
          return "Bengali";
        case "00010445":
          return "Bengali - inscript (legacy)";
        case "00020445":
          return "Bengali - inscript";
        case "0000201A":
          return "Bosnian (cyrillic)";
        case "00030402":
          return "Bulgarian";
        case "00000402":
          return "Bulgarian(typewriter)";
        case "00010402":
          return "Bulgarian (latin)";
        case "00020402":
          return "Bulgarian (phonetic)";
        case "00040402":
          return "Bulgarian (phonetic traditional)";
        case "00011009":
          return "Canada Multilingual";
        case "00001009":
          return "Canada French";
        case "00000C0C":
          return "Canada French (legacy)";
        case "00000404":
          return "Chinese (traditional) - us keyboard";
        case "00000804":
          return "Chinese (simplified) -us keyboard";
        case "00000C04":
          return "Chinese (traditional, hong kong s.a.r.) - us keyboard";
        case "00001004":
          return "Chinese (simplified, singapore) - us keyboard";
        case "00001404":
          return "Chinese (traditional, macao s.a.r.) - us keyboard";
        case "00000405":
          return "Czech";
        case "00020405":
          return "Czech programmers";
        case "00010405":
          return "Czech (qwerty)";
        case "0000041A":
          return "Croatian";
        case "00000439":
          return "Deanagari - inscript";
        case "00000406":
          return "Danish";
        case "00000465":
          return "Divehi phonetic";
        case "00010465":
          return "Divehi typewriter";
        case "00000413":
          return "Dutch";
        case "00000425":
          return "Estonian";
        case "00000438":
          return "Faeroese";
        case "0000040B":
          return "Finnish";
        case "0001083B":
          return "Finnish with sami";
        case "0000040C":
          return "French";
        case "00011809":
          return "Gaelic";
        case "00000437":
          return "Georgian";
        case "00020437":
          return "Georgian (ergonomic)";
        case "00010437":
          return "Georgian (qwerty)";
        case "00000407":
          return "German";
        case "00010407":
          return "German (ibm)";
        case "0000046F":
          return "Greenlandic";
        case "00000468":
          return "Hausa";
        case "0000040D":
          return "Hebrew";
        case "00010439":
          return "Hindi traditional";
        case "00000408":
          return "Greek";
        case "00010408":
          return "Greek (220)";
        case "00030408":
          return "Greek (220) latin";
        case "00020408":
          return "Greek (319)";
        case "00040408":
          return "Greek (319) latin";
        case "00050408":
          return "Greek latin";
        case "00060408":
          return "Greek polyonic";
        case "00000447":
          return "Gujarati";
        case "0000040E":
          return "Hungarian";
        case "0001040E":
          return "Hungarian 101 key";
        case "0000040F":
          return "Icelandic";
        case "00000470":
          return "Igbo";
        case "0000085D":
          return "Inuktitut - latin";
        case "0001045D":
          return "Inuktitut - naqittaut";
        case "00001809":
          return "Irish";
        case "00000410":
          return "Italian";
        case "00010410":
          return "Italian (142)";
        case "00000411":
          return "Japanese";
        case "0000044B":
          return "Kannada";
        case "0000043F":
          return "Kazakh";
        case "00000453":
          return "Khmer";
        case "00000412":
          return "Korean";
        case "00000440":
          return "Kyrgyz cyrillic";
        case "00000454":
          return "Lao";
        case "0000080A":
          return "Latin america";
        case "00000426":
          return "Latvian";
        case "00010426":
          return "Latvian (qwerty)";
        case "00010427":
          return "Lithuanian";
        case "00000427":
          return "Lithuanian ibm";
        case "00020427":
          return "Lithuanian standard";
        case "0000046E":
          return "Luxembourgish";
        case "0000042F":
          return "Macedonian (fyrom)";
        case "0001042F":
          return "Macedonian (fyrom) - standard";
        case "0000044C":
          return "Malayalam";
        case "0000043A":
          return "Maltese 47-key";
        case "0001043A":
          return "Maltese 48-key";
        case "0000044E":
          return "Marathi";
        case "00000481":
          return "Maroi";
        case "00000450":
          return "Mongolian cyrillic";
        case "00000850":
          return "Mongolian (mongolian script)";
        case "00000461":
          return "Nepali";
        case "00000414":
          return "Norwegian";
        case "0000043B":
          return "Norwegian with sami";
        case "00000448":
          return "Oriya";
        case "00000463":
          return "Pashto (afghanistan)";
        case "00000429":
          return "Persian";
        case "00000415":
          return "Polish (programmers)";
        case "00010415":
          return "Polish (214)";
        case "00000816":
          return "Portuguese";
        case "00000416":
          return "Portuguese (brazillian abnt)";
        case "00010416":
          return "Portuguese (brazillian abnt2)";
        case "00000446":
          return "Punjabi";
        case "00010418":
          return "Romanian (standard)";
        case "00000418":
          return "Romanian (legacy)";
        case "00020418":
          return "Romanian (programmers)";
        case "00000419":
          return "Russian";
        case "00010419":
          return "Russian (typewriter)";
        case "0002083B":
          return "Sami extended finland-sweden";
        case "0001043B":
          return "Sami extended norway";
        case "00000C1A":
          return "Serbian (cyrillic)";
        case "0000081A":
          return "Serbian (latin)";
        case "0000046C":
          return "Sesotho sa Leboa";
        case "00000432":
          return "Setswana";
        case "0000045B":
          return "Sinhala";
        case "0001045B":
          return "Sinhala -Wij 9";
        case "0000041B":
          return "Slovak";
        case "0001041B":
          return "Slovak (qwerty)";
        case "00000424":
          return "Slovenian";
        case "0001042E":
          return "Sorbian extended";
        case "0002042E":
          return "Sorbian standard";
        case "0000042E":
          return "Sorbian standard (legacy)";
        case "0000040A":
          return "Spanish";
        case "0001040A":
          return "Spanish variation";
        case "0000041D":
          return "Swedish";
        case "0000083B":
          return "Swedish with sami";
        case "00000807":
          return "Swiss german";
        case "0000100C":
          return "Swiss french";
        case "0000045A":
          return "Syriac";
        case "0001045A":
          return "Syriac phonetic";
        case "00000428":
          return "Tajik";
        case "00000449":
          return "Tamil";
        case "00000444":
          return "Tatar";
        case "0000044A":
          return "Telugu";
        case "0000041E":
          return "Thai Kedmanee";
        case "0002041E":
          return "Thai Kedmanee (non-shiftlock)";
        case "0001041E":
          return "Thai Pattachote";
        case "0003041E":
          return "Thai Pattachote (non-shiftlock)";
        case "00000451":
          return "Tibetan (prc)";
        case "0001041F":
          return "Turkish F";
        case "0000041F":
          return "Turkish Q";
        case "00000442":
          return "Turkmen";
        case "00000422":
          return "Ukrainian";
        case "00020422":
          return "Ukrainian (enhanced)";
        case "00000809":
          return "United Kingdom";
        case "00000452":
          return "United Kingdom Extended";
        case "00000409":
          return "United States";
        case "00010409":
          return "United States - dvorak";
        case "00030409":
          return "United States - dvorak left hand";
        case "00050409":
          return "United States - dvorak right hand";
        case "00004009":
          return "United States - india";
        case "00020409":
          return "United States - international";
        case "00000420":
          return "Urdu";
        case "00010480":
          return "Uyghur";
        case "00000480":
          return "Uyghur (legacy)";
        case "00000843":
          return "Uzbek cyrillic";
        case "0000042A":
          return "Vietnamese";
        case "00000485":
          return "Yakut";
        case "0000046A":
          return "Yoruba";
        case "00000488":
          return "Wolof";

        default:
          return "unknown";
      }
    }
  }
}

简短回答：

// https://learn.microsoft.com/windows/win32/intl/using-registry-string-redirection#create-resources-for-keyboard-layout-strings
using RegistryKey? key = Registry.LocalMachine.OpenSubKey($@"{KeyboardLayoutsRegistryPath}\{layoutName}");
if (key is not null)
{
    // Localizable string resource associated with the keyboard layout
    if (key.GetValue("Layout Display Name") is string layoutDisplayName &&
        SHLoadIndirectString(ref layoutDisplayName))
    {
        return layoutDisplayName;
    }

    // Fallback to human-readable name for backward compatibility
    if (key.GetValue("Layout Text") is string layoutText)
    {
        return layoutText;
    }
}

internal static unsafe bool SHLoadIndirectString(ref string source)
{
    var ppvReserved = (void*)IntPtr.Zero;
    Span<char> buffer = stackalloc char[512];
    fixed (char* pBuffer = buffer)
    {
        if (PInvoke.SHLoadIndirectString(source, pBuffer, (uint)buffer.Length, ref ppvReserved) == HRESULT.S_OK)
        {
            source = buffer.SliceAtFirstNull().ToString();
            return true;
        }
    }

    return false;
}

您可以看看System.Windows.Forms/src/System/Windows/Forms/InputLanguage.cs，它现在的实现有些不完整。
正确的算法为posted here：
键盘布局名称信息位于HKEY_LOCAL_MACHINE\system\currentcontrolset\control\keyboard layouts中。我认为. NET代码应使用GetKeyboardLayoutList的低位字，并遍历HKLM\SystemCurrentControlSet\Control\Keyboard Layouts中的所有条目，以查找匹配的低位字。当低位字匹配时，如果高位字&0xF000，则查找与布局ID的匹配。如果高位字&0xF000 == 0，则使用高位字查找HKEY_LOCAL_MACHINE\system\currentcontrolset\control\keyboard layouts中的条目。
例如，如果我在GetKeyboardLayoutList中有一个像0x040C0409这样的条目，这将指示使用法语键盘布局的英语语言。我认为在这种情况下，您会希望在0000040C下查找该条目。
找到正确的注册表路径HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layouts\后，您可以使用SHLoadIndirectString调用从Layout Display Name键获取本地化的键盘布局名称（还有Layout Text键是用于遗留目的的布局名称），如此处所述。
第一节第一节第一节第一节第一节第二节第一节

• • 更新**：System.Windows.Forms.InputLanguage.LayoutName已修复。

没有内置函数可以完成此操作。您可能需要使用此处发布的解决方案：How to convert Microsoft Locale ID (LCID) into language code