Dpi awareness support (#5)

* Rework library for supporting dpi awareness:
- All values returns in wpf units
- Project update for StyleCop rules
- Bugfix for SystemInformation.VirtualScreen returning only primary screen

* Added test project for window position check (keep in mind that you should set WindowStyle="None" ResizeMode="NoResize" properties for window or you will get position problem. See dotnet/wpf#4127)

* Fix for MONITORINFOEX initialization after code cleanup

* Final changes

WindowHelper added; Some fixes for SystemInformation;

* code review

* simplify build batch using dotnet tool

* upgrade to netcoreapp3.1 because netcoreapp3.0 is out of support

* bump version to v1.1.0

Co-authored-by: andbayd <andrew@monosnap.com>
Co-authored-by: Michael Denny <micdenny@gmail.com>

WpfScreenHelper.sln

@@ -14,6 +14,12 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		README.md = README.md
 	EndProjectSection
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WpfScreenHelper.DpiTestWpfApp", "test\WpfScreenHelper.DpiTestWpfApp\WpfScreenHelper.DpiTestWpfApp.csproj", "{FB65A9A4-4376-4CBC-A53E-0415B8D41DBB}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{9C9345A1-727D-4C83-98C8-BB3084B4CFD8}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "test", "test", "{0F6F0B6D-1C32-4681-9B6C-0CE92D22C5D1}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -24,10 +30,18 @@ Global
 		{8346EB2E-BFBB-4D63-B974-352A4D8C07F1}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{8346EB2E-BFBB-4D63-B974-352A4D8C07F1}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{8346EB2E-BFBB-4D63-B974-352A4D8C07F1}.Release|Any CPU.Build.0 = Release|Any CPU
+		{FB65A9A4-4376-4CBC-A53E-0415B8D41DBB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FB65A9A4-4376-4CBC-A53E-0415B8D41DBB}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FB65A9A4-4376-4CBC-A53E-0415B8D41DBB}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FB65A9A4-4376-4CBC-A53E-0415B8D41DBB}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{8346EB2E-BFBB-4D63-B974-352A4D8C07F1} = {9C9345A1-727D-4C83-98C8-BB3084B4CFD8}
+		{FB65A9A4-4376-4CBC-A53E-0415B8D41DBB} = {0F6F0B6D-1C32-4681-9B6C-0CE92D22C5D1}
+	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {BAF8370C-EA3E-4F99-A94C-FFC687353E0F}
 	EndGlobalSection

build.bat

@@ -4,7 +4,7 @@ echo Removing old packages...
 del Package\*.nupkg >nul 2>&1
 
 echo Building...
-"C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Current\Bin\msbuild.exe" "WpfScreenHelper.sln" /property:Configuration=Release
+dotnet build -c Release
 
 echo.
 echo ------------------------------------------------

src/WpfScreenHelper/Enum/WindowPositions.cs

@@ -0,0 +1,16 @@
+namespace WpfScreenHelper.Enum
+{
+    public enum WindowPositions
+    {
+        Center,
+        Left,
+        Top,
+        Right,
+        Bottom,
+        TopLeft,
+        TopRight,
+        BottomRight,
+        BottomLeft,
+        Maximize
+    }
+}

src/WpfScreenHelper/ExternDll.cs

@@ -4,5 +4,6 @@ internal class ExternDll
     {
         public const string User32 = "user32.dll";
         public const string Gdi32 = "gdi32.dll";
+        public const string Shcore = "shcore.dll";
     }
 }

src/WpfScreenHelper/MouseHelper.cs

@@ -1,17 +1,23 @@
-using System.Windows;
-
-namespace WpfScreenHelper
+namespace WpfScreenHelper
 {
+    using System.Windows;
+
+    /// <summary>
+    /// Provides helper functions for mouse cursor.
+    /// </summary>
     public static class MouseHelper
     {
+        /// <summary>
+        /// Gets the position of the mouse cursor in screen coordinates.
+        /// </summary>
         public static Point MousePosition
         {
             get
             {
-                NativeMethods.POINT pt = new NativeMethods.POINT();
+                var pt = new NativeMethods.POINT();
                 NativeMethods.GetCursorPos(pt);
                 return new Point(pt.x, pt.y);
             }
         }
     }
-}
+}

src/WpfScreenHelper/NativeMethods.cs

@@ -7,37 +7,98 @@ namespace WpfScreenHelper
 {
     internal static class NativeMethods
     {
+        public delegate bool MonitorEnumProc(IntPtr monitor, IntPtr hdc, IntPtr lprcMonitor, IntPtr lParam);
+
+        public enum DpiType
+        {
+            EFFECTIVE = 0,
+            ANGULAR = 1,
+            RAW = 2
+        }
+
+        public enum PROCESS_DPI_AWARENESS
+        {
+            PROCESS_DPI_UNAWARE = 0,
+            PROCESS_SYSTEM_DPI_AWARE = 1,
+            PROCESS_PER_MONITOR_DPI_AWARE = 2
+        }
+
+        public enum SystemMetric
+        {
+            SM_CXSCREEN = 0,
+            SM_CYSCREEN = 1,
+            SM_XVIRTUALSCREEN = 76,
+            SM_YVIRTUALSCREEN = 77,
+            SM_CXVIRTUALSCREEN = 78,
+            SM_CYVIRTUALSCREEN = 79,
+            SM_CMONITORS = 80
+        }
+
+        public enum SPI : uint
+        {
+            /// <summary>
+            /// Retrieves the size of the work area on the primary display monitor. The work area is the portion of the screen not obscured
+            /// by the system taskbar or by application desktop toolbars. The pvParam parameter must point to a RECT structure that receives
+            /// the coordinates of the work area, expressed in virtual screen coordinates.
+            /// To get the work area of a monitor other than the primary display monitor, call the GetMonitorInfo function.
+            /// </summary>
+            SPI_GETWORKAREA = 0x0030
+        }
+
+        [Flags]
+        public enum SPIF
+        {
+            None = 0x00,
+            /// <summary>Writes the new system-wide parameter setting to the user profile.</summary>
+            SPIF_UPDATEINIFILE = 0x01,
+            /// <summary>Broadcasts the WM_SETTINGCHANGE message after updating the user profile.</summary>
+            SPIF_SENDCHANGE = 0x02,
+            /// <summary>Same as SPIF_SENDCHANGE.</summary>
+            SPIF_SENDWININICHANGE = 0x02
+        }
+
+        public const int SPI_GETWORKAREA = 48;
+
+        public static readonly HandleRef NullHandleRef = new HandleRef(null, IntPtr.Zero);
+
+        [DllImport(ExternDll.Shcore, CharSet = CharSet.Auto)]
+        [ResourceExposure(ResourceScope.None)]
+        public static extern int GetProcessDpiAwareness(IntPtr hprocess, out PROCESS_DPI_AWARENESS value);
+
+        [DllImport(ExternDll.Shcore, CharSet = CharSet.Auto)]
+        [ResourceExposure(ResourceScope.None)]
+        public static extern IntPtr GetDpiForMonitor([In] IntPtr hmonitor, [In] DpiType dpiType, [Out] out uint dpiX, [Out] out uint dpiY);
+
         [DllImport(ExternDll.User32, CharSet = CharSet.Auto)]
         [ResourceExposure(ResourceScope.None)]
-        public static extern bool GetMonitorInfo(HandleRef hmonitor, [In, Out] MONITORINFOEX info);
+        public static extern bool GetMonitorInfo(HandleRef hmonitor, [In][Out] MONITORINFOEX info);
 
         [DllImport(ExternDll.User32, ExactSpelling = true)]
         [ResourceExposure(ResourceScope.None)]
         public static extern bool EnumDisplayMonitors(HandleRef hdc, COMRECT rcClip, MonitorEnumProc lpfnEnum, IntPtr dwData);
-        
+
         [DllImport(ExternDll.User32, ExactSpelling = true)]
         [ResourceExposure(ResourceScope.None)]
         public static extern IntPtr MonitorFromWindow(HandleRef handle, int flags);
 
         [DllImport(ExternDll.User32, ExactSpelling = true, CharSet = CharSet.Auto)]
         [ResourceExposure(ResourceScope.None)]
-        public static extern int GetSystemMetrics(int nIndex);
+        public static extern int GetSystemMetrics(SystemMetric nIndex);
 
         [DllImport(ExternDll.User32, CharSet = CharSet.Auto)]
         [ResourceExposure(ResourceScope.None)]
-        public static extern bool SystemParametersInfo(int nAction, int nParam, ref RECT rc, int nUpdate);
+        public static extern bool SystemParametersInfo(SPI nAction, int nParam, ref RECT rc, SPIF nUpdate);
 
         [DllImport(ExternDll.User32, ExactSpelling = true)]
         [ResourceExposure(ResourceScope.None)]
         public static extern IntPtr MonitorFromPoint(POINTSTRUCT pt, int flags);
 
         [DllImport(ExternDll.User32, ExactSpelling = true, CharSet = CharSet.Auto)]
         [ResourceExposure(ResourceScope.None)]
-        public static extern bool GetCursorPos([In, Out] POINT pt);
+        public static extern bool GetCursorPos([In][Out] POINT pt);
 
-        public static readonly HandleRef NullHandleRef = new HandleRef(null, IntPtr.Zero);
-
-        public delegate bool MonitorEnumProc(IntPtr monitor, IntPtr hdc, IntPtr lprcMonitor, IntPtr lParam);
+        [DllImport(ExternDll.User32, SetLastError = true)]
+        public static extern bool IsProcessDPIAware();
 
         [StructLayout(LayoutKind.Sequential)]
         public struct RECT
@@ -57,21 +118,18 @@ public RECT(int left, int top, int right, int bottom)
 
             public RECT(Rect r)
             {
-                this.left = (int)r.Left;
-                this.top = (int)r.Top;
-                this.right = (int)r.Right;
-                this.bottom = (int)r.Bottom;
+                left = (int)r.Left;
+                top = (int)r.Top;
+                right = (int)r.Right;
+                bottom = (int)r.Bottom;
             }
 
             public static RECT FromXYWH(int x, int y, int width, int height)
             {
                 return new RECT(x, y, x + width, y + height);
             }
 
-            public Size Size
-            {
-                get { return new Size(this.right - this.left, this.bottom - this.top); }
-            }
+            public Size Size => new Size(right - left, bottom - top);
         }
 
         // use this in cases where the Native API takes a POINT not a POINT*
@@ -81,6 +139,7 @@ public struct POINTSTRUCT
         {
             public int x;
             public int y;
+
             public POINTSTRUCT(int x, int y)
             {
                 this.x = x;
@@ -116,30 +175,33 @@ public override string ToString()
         public class MONITORINFOEX
         {
             internal int cbSize = Marshal.SizeOf(typeof(MONITORINFOEX));
+
             internal RECT rcMonitor = new RECT();
             internal RECT rcWork = new RECT();
             internal int dwFlags = 0;
-            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)] internal char[] szDevice = new char[32];
+
+            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
+            internal char[] szDevice = new char[32];
         }
 
         [StructLayout(LayoutKind.Sequential)]
         public class COMRECT
         {
+            public int bottom;
             public int left;
-            public int top;
             public int right;
-            public int bottom;
+            public int top;
 
             public COMRECT()
             {
             }
 
             public COMRECT(Rect r)
             {
-                this.left = (int)r.X;
-                this.top = (int)r.Y;
-                this.right = (int)r.Right;
-                this.bottom = (int)r.Bottom;
+                left = (int)r.X;
+                top = (int)r.Y;
+                right = (int)r.Right;
+                bottom = (int)r.Bottom;
             }
 
             public COMRECT(int left, int top, int right, int bottom)
@@ -160,10 +222,5 @@ public override string ToString()
                 return "Left = " + left + " Top " + top + " Right = " + right + " Bottom = " + bottom;
             }
         }
-
-        public const int SM_CMONITORS = 80,
-                         SM_CXSCREEN = 0,
-                         SM_CYSCREEN = 1,
-                         SPI_GETWORKAREA = 48;
     }
 }