fixed a bug of window

src/Shared/HandyControl_Shared/Tools/Helper/DpiHelper.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Windows;
+using System.Windows.Media;
+
+namespace HandyControl.Tools
+{
+    internal class DpiHelper
+    {
+        [ThreadStatic]
+        private static Matrix _transformToDip;
+
+        public static Point DevicePixelsToLogical(Point devicePoint, double dpiScaleX, double dpiScaleY)
+        {
+            _transformToDip = Matrix.Identity;
+            _transformToDip.Scale(1d / dpiScaleX, 1d / dpiScaleY);
+            return _transformToDip.Transform(devicePoint);
+        }
+
+        public static Size DeviceSizeToLogical(Size deviceSize, double dpiScaleX, double dpiScaleY)
+        {
+            Point pt = DevicePixelsToLogical(new Point(deviceSize.Width, deviceSize.Height), dpiScaleX, dpiScaleY);
+
+            return new Size(pt.X, pt.Y);
+        }
+    }
+}