//获取子节点数量
Console.WriteLine(Registry.LocalMachine.SubKeyCount);

//获取所有自己点的键值
string[] subs = Registry.LocalMachine.GetSubKeyNames();
foreach (var item in subs)
{
    Console.WriteLine(item);
}

//打开子节点
RegistryKey sub1 = Registry.LocalMachine.OpenSubKey(subs[0]);
Console.WriteLine(sub1.Name); //HKEY_LOCAL_MACHINE\BCD00000000

//打开子节点2,特别说明不能\开头，不能包含根节点
RegistryKey sub2 = Registry.LocalMachine.OpenSubKey(@"BCD00000000\Description", true);
Console.WriteLine(sub2.Name);//HKEY_LOCAL_MACHINE\BCD00000000\Description

//获取项下的 键值
string[] names = sub2.GetValueNames();
foreach (var item in names)
{
    //获取值
    Console.WriteLine(item + "--->" + sub2.GetValue(item));
}

//特别注意，如果想写入内容，在打开注册表的时候writable，需要设置成true
//创建键值
sub2.SetValue("zhangsan", "1234", RegistryValueKind.String);

//创建子项
RegistryKey sub3 = sub2.CreateSubKey("sub3");
sub3.SetValue("sub3_key", 1100, RegistryValueKind.DWord);

//打开子节点2,特别说明不能\开头，不能包含根节点
RegistryKey sub2 = Registry.LocalMachine.OpenSubKey(@"BCD00000000\Description", true);
Console.WriteLine(sub2.Name);//HKEY_LOCAL_MACHINE\BCD00000000\Description