DnD fix

src/Avalonia.Controls/Platform/InProcessDragSource.cs

@@ -56,16 +56,11 @@ namespace Avalonia.Platform
             return DragDropEffects.None;
         }
 
-
-        private DragDropEffects RaiseEventAndUpdateCursor(RawDragEventType type, IInputElement root, Point pt,
-            InputModifiers modifiers)
-            => RaiseEventAndUpdateCursor(type, root, pt, (RawInputModifiers)modifiers);
-        
         private DragDropEffects RaiseEventAndUpdateCursor(RawDragEventType type, IInputElement root, Point pt, RawInputModifiers modifiers)
         {
             _lastPosition = pt;
 
-            RawDragEvent rawEvent = new RawDragEvent(_dragDrop, type, root, pt, _draggedData, _allowedEffects, (InputModifiers)modifiers);
+            RawDragEvent rawEvent = new RawDragEvent(_dragDrop, type, root, pt, _draggedData, _allowedEffects, modifiers);
             var tl = root.GetSelfAndVisualAncestors().OfType<TopLevel>().FirstOrDefault();
             tl.PlatformImpl?.Input(rawEvent);
 
@@ -164,7 +159,7 @@ namespace Avalonia.Platform
                 _initialInputModifiers = e.InputModifiers & MOUSE_INPUTMODIFIERS;
 
             
-            void CheckDraggingAccepted(InputModifiers changedMouseButton)
+            void CheckDraggingAccepted(RawInputModifiers changedMouseButton)
             {
                 if (_initialInputModifiers.Value.HasFlag(changedMouseButton))
                 {
@@ -189,11 +184,11 @@ namespace Avalonia.Platform
                 case RawPointerEventType.LeaveWindow:
                     RaiseEventAndUpdateCursor(RawDragEventType.DragLeave, e.Root, e.Position,  e.InputModifiers); break;
                 case RawPointerEventType.LeftButtonUp:
-                    CheckDraggingAccepted(InputModifiers.LeftMouseButton); break;
+                    CheckDraggingAccepted(RawInputModifiers.LeftMouseButton); break;
                 case RawPointerEventType.MiddleButtonUp:
-                    CheckDraggingAccepted(InputModifiers.MiddleMouseButton); break;
+                    CheckDraggingAccepted(RawInputModifiers.MiddleMouseButton); break;
                 case RawPointerEventType.RightButtonUp:
-                    CheckDraggingAccepted(InputModifiers.RightMouseButton); break;
+                    CheckDraggingAccepted(RawInputModifiers.RightMouseButton); break;
                 case RawPointerEventType.Move:
                     var mods = e.InputModifiers & MOUSE_INPUTMODIFIERS;
                     if (_initialInputModifiers.Value != mods)

src/Avalonia.Input/Raw/RawDragEvent.cs

@@ -10,7 +10,7 @@
         public InputModifiers Modifiers { get; }
 
         public RawDragEvent(IDragDropDevice inputDevice, RawDragEventType type, 
-            IInputElement inputRoot, Point location, IDataObject data, DragDropEffects effects, InputModifiers modifiers)
+            IInputElement inputRoot, Point location, IDataObject data, DragDropEffects effects, RawInputModifiers modifiers)
             :base(inputDevice, 0)
         {
             Type = type;
@@ -18,7 +18,7 @@
             Location = location;
             Data = data;
             Effects = effects;
-            Modifiers = modifiers;
+            Modifiers = (InputModifiers)modifiers;
         }
     }
 }

src/Windows/Avalonia.Win32/OleDropTarget.cs

@@ -45,23 +45,23 @@ namespace Avalonia.Win32
             return result;
         }
         
-        private static InputModifiers ConvertKeyState(int grfKeyState)
+        private static RawInputModifiers ConvertKeyState(int grfKeyState)
         {
-            InputModifiers modifiers = InputModifiers.None;
+            var modifiers = RawInputModifiers.None;
             var state = (UnmanagedMethods.ModifierKeys)grfKeyState;
 
             if (state.HasFlag(UnmanagedMethods.ModifierKeys.MK_LBUTTON))
-                modifiers |= InputModifiers.LeftMouseButton;
+                modifiers |= RawInputModifiers.LeftMouseButton;
             if (state.HasFlag(UnmanagedMethods.ModifierKeys.MK_MBUTTON))
-                modifiers |= InputModifiers.MiddleMouseButton;
+                modifiers |= RawInputModifiers.MiddleMouseButton;
             if (state.HasFlag(UnmanagedMethods.ModifierKeys.MK_RBUTTON))
-                modifiers |= InputModifiers.RightMouseButton;
+                modifiers |= RawInputModifiers.RightMouseButton;
             if (state.HasFlag(UnmanagedMethods.ModifierKeys.MK_SHIFT))
-                modifiers |= InputModifiers.Shift;
+                modifiers |= RawInputModifiers.Shift;
             if (state.HasFlag(UnmanagedMethods.ModifierKeys.MK_CONTROL))
-                modifiers |= InputModifiers.Control;
+                modifiers |= RawInputModifiers.Control;
             if (state.HasFlag(UnmanagedMethods.ModifierKeys.MK_ALT))
-                modifiers |= InputModifiers.Alt;
+                modifiers |= RawInputModifiers.Alt;
             return modifiers;
         }
 
@@ -127,7 +127,7 @@ namespace Avalonia.Win32
                     default(Point),
                     null,
                     DragDropEffects.None,
-                    InputModifiers.None
+                    RawInputModifiers.None
                 ));
                 return UnmanagedMethods.HRESULT.S_OK;
             }