Merge pull request #452 from KvanTTT/master

Fixed DPI scaling .dll not found. fixed #449

src/Windows/Perspex.Win32/Interop/UnmanagedMethods.cs

@@ -742,6 +742,9 @@ namespace Perspex.Win32.Interop
         [DllImport("kernel32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
         public static extern IntPtr GlobalFree(IntPtr hMem);
 
+        [DllImport("kernel32.dll", SetLastError = true)]
+        public static extern IntPtr LoadLibrary(string fileName);
+
         [DllImport("comdlg32.dll", CharSet = CharSet.Unicode, EntryPoint = "GetSaveFileNameW")]
         public static extern bool GetSaveFileName(IntPtr lpofn);
 
@@ -751,6 +754,8 @@ namespace Perspex.Win32.Interop
         [DllImport("comdlg32.dll")]
         public static extern int CommDlgExtendedError();
 
+        public static bool ShCoreAvailable => LoadLibrary("shcore.dll") != IntPtr.Zero;
+
         [DllImport("shcore.dll")]
         public static extern void SetProcessDpiAwareness(PROCESS_DPI_AWARENESS value);
 

src/Windows/Perspex.Win32/Win32Platform.cs

@@ -28,8 +28,11 @@ namespace Perspex.Win32
 
         public Win32Platform()
         {
-            // Declare that this process is aware of per monitor DPI 
-            UnmanagedMethods.SetProcessDpiAwareness(UnmanagedMethods.PROCESS_DPI_AWARENESS.PROCESS_PER_MONITOR_DPI_AWARE);
+            // Declare that this process is aware of per monitor DPI
+            if (UnmanagedMethods.ShCoreAvailable)
+            {
+                UnmanagedMethods.SetProcessDpiAwareness(UnmanagedMethods.PROCESS_DPI_AWARENESS.PROCESS_PER_MONITOR_DPI_AWARE);
+            }
 
             CreateMessageWindow();
         }

src/Windows/Perspex.Win32/WindowImpl.cs

@@ -609,14 +609,17 @@ namespace Perspex.Win32
                 _hwnd, 
                 UnmanagedMethods.MONITOR.MONITOR_DEFAULTTONEAREST);
 
-            uint dpix, dpiy;
-            if (UnmanagedMethods.GetDpiForMonitor(
-                    monitor, 
-                    UnmanagedMethods.MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI, 
-                    out dpix, 
-                    out dpiy) == 0)
+            if (UnmanagedMethods.ShCoreAvailable)
             {
-                _scaling = dpix / 96.0;
+                uint dpix, dpiy;
+                if (UnmanagedMethods.GetDpiForMonitor(
+                        monitor,
+                        UnmanagedMethods.MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI,
+                        out dpix,
+                        out dpiy) == 0)
+                {
+                    _scaling = dpix / 96.0;
+                }
             }
         }