C#. How to get value from registry?

Question

C++ / C#

Good afternoon.
I'm trying to get a value from the registry in a Windows Forms project.
But I am getting errors. Tell me what did you do wrong?
And how to assign label1 as a result?

public MainForm()
    {
      //
      // The InitializeComponent() call is required for Windows Forms designer support.
      //
      InitializeComponent();
      RegistryKey readKey = Registry.CurrentUser.OpenSubKey("\\Software\\Microsoft\\Internet Explorer\\Main\\FeatureControl\\FEATURE_BROWSER_EMULATION");
      string loadString = (string)readKey.GetValue("devenv.exe");
      readKey.Close();
//
      // TODO: Add constructor code after the InitializeComponent() call.
      //
    }

Mistake:

System.NullReferenceException: Ссылка на объект не указывает на экземпляр объекта.

   в tttosto.MainForm..ctor() в c:\User\Documents\SharpDevelop Projects\tttosto\tttosto\MainForm.cs:строка 29
   в tttosto.Program.Main(String[] args) в c:\User\Documents\SharpDevelop Projects\tttosto\tttosto\Program.cs:строка 27

Line 29 in Mainform - string loadString = (string)readKey.GetValue("devenv.exe");
Line 27 in Program - Application.Run(new MainForm());

Answer 1

There shouldn't be any slashes at the beginning . And then you can not immediately translate into the text. First you need to find out what type the key isOpenSubKey("Software\\
GetValueKind(name)