CorDebugger.cs

private static CorDebugger GetDebugger()
{
    Guid classId = new Guid("9280188D-0E8E-4867-B30C-7FA83884E8DE");        
    Guid interfaceId = new Guid("D332DB9E-B9B3-4125-8207-A14884F53216");

    dynamic rawMetaHost;
    Microsoft.Samples.Debugging.CorDebug.NativeMethods.CLRCreateInstance(ref classId, ref interfaceId, out rawMetaHost);
    ICLRMetaHost metaHost = (ICLRMetaHost)rawMetaHost;

    var currentProcess = Process.GetCurrentProcess();
    var runtime_v40 = GetLoadedRuntimeByVersion(metaHost, currentProcess.Id, "v4.0");

    var debuggerClassId = new Guid("DF8395B5-A4BA-450B-A77C-A9A47762C520");
    var debuggerInterfaceId = new Guid("3D6F5F61-7538-11D3-8D5B-00104B35E7EF");

    //Get a debugger for this version of the runtime. 
    Object res = runtime_v40.m_runtimeInfo.GetInterface(ref debuggerClassId, ref debuggerInterfaceId);
    ICorDebug debugger = (ICorDebug)res;
    
    //We create CorDebugger that wraps the ICorDebug stuff making it easier to use
    var corDebugger = new CorDebugger(debugger);
    return corDebugger;
}

public static CLRRuntimeInfo GetLoadedRuntimeByVersion(ICLRMetaHost metaHost, Int32 processId, string version)
{
    IEnumerable<CLRRuntimeInfo> runtimes = EnumerateLoadedRuntimes(metaHost, processId);

    foreach (CLRRuntimeInfo rti in runtimes)
    {
        //Search through all loaded runtimes for one that starts with v4.0. 
        if (rti.GetVersionString().StartsWith(version, StringComparison.OrdinalIgnoreCase))
        {
            return rti;
        }
    }

    return null;
}

public static IEnumerable<CLRRuntimeInfo> EnumerateLoadedRuntimes(ICLRMetaHost metaHost, Int32 processId)
{
    List<CLRRuntimeInfo> runtimes = new List<CLRRuntimeInfo>();
    IEnumUnknown enumRuntimes;

    //We get a handle for the process and then get all the runtimes available from it.
    using (ProcessSafeHandle hProcess = NativeMethods.OpenProcess((int)(NativeMethods.ProcessAccessOptions.ProcessVMRead |
                                        NativeMethods.ProcessAccessOptions.ProcessQueryInformation |
                                        NativeMethods.ProcessAccessOptions.ProcessDupHandle |
                                        NativeMethods.ProcessAccessOptions.Synchronize),
                                        false, // inherit handle
                                        processId))
    {
        if (hProcess.IsInvalid)
        {
            throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
        }

        enumRuntimes = metaHost.EnumerateLoadedRuntimes(hProcess);
    }

    // Since we're only getting one at a time, we can pass NULL for count.
    // S_OK also means we got the single element we asked for.
    for (object oIUnknown; enumRuntimes.Next(1, out oIUnknown, IntPtr.Zero) == 0; /* empty */)
    {
        runtimes.Add(new CLRRuntimeInfo(oIUnknown));
    }

    return runtimes;
}