new folder structure and new C# script host

src/Native/Taskbar.cs

@@ -0,0 +1,55 @@
+
+using System;
+using System.Runtime.InteropServices;
+
+public class Taskbar
+{
+    public IntPtr Handle { get; set; }
+
+    public Taskbar(IntPtr handle) => Handle = handle;
+ 
+    ITaskbarList3 Instance = (ITaskbarList3)new TaskBarCommunication();
+
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    [Guid("EA1AFB91-9E28-4B86-90E9-9E9F8A5EEFAF")]
+    interface ITaskbarList3
+    {
+        // ITaskbarList
+        [PreserveSig] void HrInit();
+        [PreserveSig] void AddTab(IntPtr hwnd);
+        [PreserveSig] void DeleteTab(IntPtr hwnd);
+        [PreserveSig] void ActivateTab(IntPtr hwnd);
+        [PreserveSig] void SetActiveAlt(IntPtr hwnd);
+        // ITaskbarList2
+        [PreserveSig] void MarkFullscreenWindow(IntPtr hwnd, [MarshalAs(UnmanagedType.Bool)] bool fFullscreen);
+        // ITaskbarList3
+        [PreserveSig] void SetProgressValue(IntPtr hwnd, ulong ullCompleted, ulong ullTotal);
+        [PreserveSig] void SetProgressState(IntPtr hwnd, TaskbarStates state);
+    }
+
+    [ComImport]
+    [ClassInterface(ClassInterfaceType.None)]
+    [Guid("56FDF344-FD6D-11d0-958A-006097C9A090")]
+    class TaskBarCommunication
+    {
+    }
+
+    public void SetState(TaskbarStates taskbarState)
+    {
+        Instance.SetProgressState(Handle, taskbarState);
+    }
+
+    public void SetValue(double progressValue, double progressMax)
+    {
+        Instance.SetProgressValue(Handle, (ulong)progressValue, (ulong)progressMax);
+    }
+}
+
+public enum TaskbarStates
+{
+    NoProgress = 0,
+    Indeterminate = 0x1,
+    Normal = 0x2,
+    Error = 0x4,
+    Paused = 0x8
+}