Add shell context [WIP]

Wox/ShellContext/IContextMenu.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace Wox.ShellContext
+{
+    [ComImport(), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("000214e4-0000-0000-c000-000000000046")]
+    public interface IContextMenu
+    {
+        [PreserveSig()]
+        Int32 QueryContextMenu(
+            IntPtr hmenu,
+            uint iMenu,
+            uint idCmdFirst,
+            uint idCmdLast,
+            CMF uFlags);
+
+        [PreserveSig()]
+        Int32 InvokeCommand(
+            ref CMINVOKECOMMANDINFOEX info);
+
+        [PreserveSig()]
+        void GetCommandString(
+            int idcmd,
+            GetCommandStringInformations uflags,
+            int reserved,
+            StringBuilder commandstring,
+            int cch);
+    }
+}