fixed #886

src/Shared/HandyControl_Shared/Controls/Window/Window.cs

@@ -169,6 +169,18 @@ namespace HandyControl.Controls
                     WmGetMinMaxInfo(hwnd, lparam);
                     Padding = WindowState == WindowState.Maximized ? WindowHelper.WindowMaximizedPadding : _commonPadding;
                     break;
+                case InteropValues.WM_NCHITTEST:
+                    // for fixing #886
+                    // https://developercommunity.visualstudio.com/t/overflow-exception-in-windowchrome/167357
+                    try
+                    {
+                        _ = lparam.ToInt32();
+                    }
+                    catch (OverflowException)
+                    {
+                        handled = true;
+                    }
+                    break;
             }
 
             return IntPtr.Zero;

src/Shared/HandyControl_Shared/Tools/Interop/InteropValues.cs

@@ -56,6 +56,7 @@ namespace HandyControl.Tools.Interop
             WM_SETICON = 0x0080,
             WM_NCCREATE = 0x0081,
             WM_NCDESTROY = 0x0082,
+            WM_NCHITTEST = 0x0084,
             WM_NCACTIVATE = 0x0086,
             WM_NCRBUTTONDOWN = 0x00A4,
             WM_NCRBUTTONUP = 0x00A5,