Implemented SetIgnoreTaskBarWhenMaxmimized for Win32

src/Avalonia.Controls/Platform/IWindowImpl.cs

@@ -35,6 +35,11 @@ namespace Avalonia.Platform
         /// </summary>
         void SetSystemDecorations(bool enabled);
 
+        /// <summary>
+        /// When system decorations are disabled sets if the maximized state covers the entire screen or just the working area.
+        /// </summary>        
+        void SetIgnoreTaskBarWhenMaximized(bool enable);
+
         /// <summary>
         /// Sets the icon of this window.
         /// </summary>

src/Windows/Avalonia.Win32/WindowImpl.cs

@@ -33,6 +33,7 @@ namespace Avalonia.Win32
         private bool _trackingMouse;
         private bool _isActive;
         private bool _decorated = true;
+        private bool _ignoreTaskBarWhenMaximized = true;
         private double _scaling = 1;
         private WindowState _showWindowState;
 
@@ -688,7 +689,7 @@ namespace Avalonia.Win32
                 case WindowState.Maximized:
                     command = UnmanagedMethods.ShowWindowCommand.Maximize;
 
-                    if (!_decorated)
+                    if (!_decorated && !_ignoreTaskBarWhenMaximized)
                     {
                         IntPtr monitor = MonitorFromWindow(_hwnd, MONITOR.MONITOR_DEFAULTTONEAREST);
 
@@ -741,5 +742,15 @@ namespace Avalonia.Win32
 
             return (int)(ptr.ToInt64() & 0xffffffff);
         }
+
+        public void SetIgnoreTaskBarWhenMaximized(bool enable)
+        {
+            _ignoreTaskBarWhenMaximized = enable;
+
+            if(_showWindowState == WindowState.Maximized)
+            {
+                ShowWindow(WindowState.Maximized);
+            }
+        }
     }
 }