Dpi awareness context fixes from classic + deprecate unspecified context

src/System.Windows.Forms.Design.Editors/src/Misc/CommonUnsafeNativeMethods.cs

@@ -63,76 +63,5 @@ public static IntPtr LoadLibraryFromSystemPathIfAvailable(string libraryName)
         }
 
         #endregion
-
-        #region PInvoke DpiRelated
-        // This section could go to Nativemethods.cs or Safenativemethods.cs but we have separate copies of them in each library (System.winforms, System.Design and System.Drawing).
-        // Keeping them here will reduce duplicating code but may have to take care of security warnings (if any).
-        // These APIs are available starting Windows 10, version 1607 only.
-        [DllImport(ExternDll.User32, SetLastError = true, ExactSpelling = true, CharSet = CharSet.Auto)]
-        internal static extern DpiAwarenessContext GetThreadDpiAwarenessContext();
-
-        [DllImport(ExternDll.User32, SetLastError = true, ExactSpelling = true, CharSet = CharSet.Auto)]
-        internal static extern DpiAwarenessContext SetThreadDpiAwarenessContext(DpiAwarenessContext dpiContext);
-
-        [DllImport(ExternDll.User32, SetLastError = true, ExactSpelling = true, CharSet = CharSet.Auto)]
-        [return: MarshalAs(UnmanagedType.Bool)]
-        internal static extern bool AreDpiAwarenessContextsEqual(DpiAwarenessContext dpiContextA, DpiAwarenessContext dpiContextB);
-
-        /// <summary>
-        /// Tries to compare two DPIawareness context values. Return true if they were equal. 
-        /// Return false when they are not equal or underlying OS does not support this API.
-        /// </summary>
-        /// <returns>true/false</returns>
-        public static bool TryFindDpiAwarenessContextsEqual(DpiAwarenessContext dpiContextA, DpiAwarenessContext dpiContextB)
-        {
-            if (ApiHelper.IsApiAvailable(ExternDll.User32, "AreDpiAwarenessContextsEqual"))
-            {
-                return AreDpiAwarenessContextsEqual(dpiContextA, dpiContextB);
-            }
-
-            return false;
-        }
-
-        /// <summary>
-        /// Tries to get thread dpi awareness context
-        /// </summary>
-        /// <returns> returns thread dpi awareness context if API is available in this version of OS. otherwise, return IntPtr.Zero.</returns>
-        public static DpiAwarenessContext TryGetThreadDpiAwarenessContext()
-        {
-            if (ApiHelper.IsApiAvailable(ExternDll.User32, "GetThreadDpiAwarenessContext"))
-            {
-                return GetThreadDpiAwarenessContext();
-            }
-            else
-            {
-                // legacy OS that does not have this API available.
-                return DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED;
-            }
-        }
-
-        /// <summary>
-        /// Tries to set thread dpi awareness context
-        /// </summary>
-        /// <returns> returns old thread dpi awareness context if API is available in this version of OS. otherwise, return IntPtr.Zero.</returns>
-        public static DpiAwarenessContext TrySetThreadDpiAwarenessContext(DpiAwarenessContext dpiCOntext)
-        {
-            if (ApiHelper.IsApiAvailable(ExternDll.User32, "SetThreadDpiAwarenessContext"))
-            {
-                return SetThreadDpiAwarenessContext(dpiCOntext);
-            }
-            else
-            {
-                // legacy OS that does not have this API available.
-                return DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED;
-            }
-        }
-/*
-        // Dpi awareness context values. Matching windows values.
-        public static readonly DPI_AWARENESS_CONTEXT DPI_AWARENESS_CONTEXT_UNAWARE = (-1);
-        public static readonly DPI_AWARENESS_CONTEXT DPI_AWARENESS_CONTEXT_SYSTEM_AWARE = (-2);
-        public static readonly DPI_AWARENESS_CONTEXT DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE = (-3);
-        public static readonly DPI_AWARENESS_CONTEXT DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 = (-4);
-        public static readonly DPI_AWARENESS_CONTEXT DPI_AWARENESS_CONTEXT_UNSPECIFIED = (0);*/
-        #endregion
     }
 }

src/System.Windows.Forms.Design.Editors/src/Misc/DpiHelper.cs

@@ -290,8 +290,8 @@ internal static bool EnableDpiChangedMessageHandling
                 {
                     // We can't cache this value because different top level windows can have different DPI awareness context
                     // for mixed mode applications.
-                    DpiAwarenessContext dpiAwareness = CommonUnsafeNativeMethods.GetThreadDpiAwarenessContext();
-                    return CommonUnsafeNativeMethods.TryFindDpiAwarenessContextsEqual(dpiAwareness, DpiAwarenessContext.DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
+                    DpiAwarenessContext dpiAwareness = DpiUnsafeNativeMethods.TryGetThreadDpiAwarenessContext();
+                    return DpiUnsafeNativeMethods.TryFindDpiAwarenessContextsEqual(dpiAwareness, DpiAwarenessContext.DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
                 }
                 else
                 {

src/System.Windows.Forms.Design.Editors/src/Misc/DpiUnsafeNativeMethods.cs

@@ -0,0 +1,108 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Windows.Forms
+{
+    using Runtime.InteropServices;
+    using Runtime.Versioning;
+    using System;
+
+    internal class DpiUnsafeNativeMethods
+    {
+
+        // This section could go to Nativemethods.cs or Safenativemethods.cs but we have separate copies of them in each library (System.winforms, System.Design and System.Drawing).
+        // Keeping them here will reduce duplicating code but may have to take care of security warnings (if any).
+        // These APIs are available starting Windows 10, version 1607 only.
+
+        [DllImport(ExternDll.User32, SetLastError = true, ExactSpelling = true, CharSet = CharSet.Auto)]
+        [ResourceExposure(ResourceScope.None)]
+        internal static extern DpiAwarenessContext GetThreadDpiAwarenessContext();
+
+        [DllImport(ExternDll.User32, SetLastError = true, ExactSpelling = true, CharSet = CharSet.Auto)]
+        [ResourceExposure(ResourceScope.None)]
+        internal static extern DpiAwarenessContext SetThreadDpiAwarenessContext(DpiAwarenessContext dpiContext);
+
+        [DllImport(ExternDll.User32, SetLastError = true, ExactSpelling = true, CharSet = CharSet.Auto)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        internal static extern bool AreDpiAwarenessContextsEqual(DpiAwarenessContext dpiContextA, DpiAwarenessContext dpiContextB);
+
+        [DllImport(ExternDll.User32, SetLastError = true, ExactSpelling = true, CharSet = CharSet.Auto)]
+        [ResourceExposure(ResourceScope.None)]
+        internal static extern DpiAwarenessContext GetWindowDpiAwarenessContext(IntPtr hwnd);
+
+        /// <summary>
+        /// Tries to compare two DPIawareness context values. Return true if they were equal. 
+        /// Return false when they are not equal or underlying OS does not support this API.
+        /// </summary>
+        /// <returns>true/false</returns>
+        public static bool TryFindDpiAwarenessContextsEqual(DpiAwarenessContext dpiContextA, DpiAwarenessContext dpiContextB)
+        {
+            if(dpiContextA == DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED && dpiContextB == DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED)
+            {
+                return true;
+            }
+            if (ApiHelper.IsApiAvailable(ExternDll.User32, nameof(DpiUnsafeNativeMethods.AreDpiAwarenessContextsEqual)))
+            {
+                return AreDpiAwarenessContextsEqual(dpiContextA, dpiContextB);
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Tries to get thread dpi awareness context
+        /// </summary>
+        /// <returns> returns thread dpi awareness context if API is available in this version of OS. otherwise, return IntPtr.Zero.</returns>
+        public static DpiAwarenessContext TryGetThreadDpiAwarenessContext()
+        {
+            if (ApiHelper.IsApiAvailable(ExternDll.User32, nameof(DpiUnsafeNativeMethods.GetThreadDpiAwarenessContext)))
+            {
+                return GetThreadDpiAwarenessContext();
+            }
+            else
+            {
+                // legacy OS that does not have this API available.
+                return DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED;
+            }
+        }
+
+        /// <summary>
+        /// Tries to set thread dpi awareness context
+        /// </summary>
+        /// <returns> returns old thread dpi awareness context if API is available in this version of OS. otherwise, return IntPtr.Zero.</returns>
+        public static DpiAwarenessContext TrySetThreadDpiAwarenessContext(DpiAwarenessContext dpiContext)
+        {
+            if (ApiHelper.IsApiAvailable(ExternDll.User32, nameof(DpiUnsafeNativeMethods.SetThreadDpiAwarenessContext)))
+            {
+                if (dpiContext == DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED)
+                {
+                    throw new ArgumentException(nameof(dpiContext), dpiContext.ToString());
+                }
+                return SetThreadDpiAwarenessContext(dpiContext);
+            }
+            else
+            {
+                // legacy OS that does not have this API available.
+                return DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED;
+            }
+        }
+
+        /// <summary>
+        /// Tries to get window dpi awareness context
+        /// </summary>
+        /// <returns> returns window dpi awareness context if API is available in this version of OS. otherwise, return DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED.</returns>
+        public static DpiAwarenessContext TryGetWindowDpiAwarenessContext(IntPtr hwnd)
+        {
+            if (ApiHelper.IsApiAvailable(ExternDll.User32, "GetWindowDpiAwarenessContext"))
+            {
+                return GetWindowDpiAwarenessContext(hwnd);
+            }
+            else
+            {
+                // legacy OS that does not have this API available.
+                return DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED;
+            }
+        }
+    }
+}

src/System.Windows.Forms/src/System/Windows/Forms/Application.cs

@@ -1242,7 +1242,7 @@ private static void RaiseThreadExit() {
         ///     "Parks" the given HWND to a temporary HWND.  This allows WS_CHILD windows to
         ///     be parked.
         /// </devdoc>
-        internal static void ParkHandle(HandleRef handle, DpiAwarenessContext dpiAwarenessContext = DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED) {
+        internal static void ParkHandle(HandleRef handle, DpiAwarenessContext? dpiAwarenessContext = null) {
             Debug.Assert(UnsafeNativeMethods.IsWindow(handle), "Handle being parked is not a valid window handle");
             Debug.Assert(((int)UnsafeNativeMethods.GetWindowLong(handle, NativeMethods.GWL_STYLE) & NativeMethods.WS_CHILD) != 0, "Only WS_CHILD windows should be parked.");
 
@@ -1257,7 +1257,7 @@ internal static void ParkHandle(HandleRef handle, DpiAwarenessContext dpiAwarene
         /// </summary>
         /// <param name="cp"> create params for control handle</param>
         /// <param name="dpiContext"> dpi awareness</param>
-        internal static void ParkHandle(CreateParams cp, DpiAwarenessContext dpiAwarenessContext = DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED) {
+        internal static void ParkHandle(CreateParams cp, DpiAwarenessContext? dpiAwarenessContext = null) {
 
             ThreadContext cxt = ThreadContext.FromCurrent();
             if (cxt != null) {
@@ -1289,7 +1289,7 @@ public static void OnThreadException(Exception t) {
         ///     "Unparks" the given HWND to a temporary HWND.  This allows WS_CHILD windows to
         ///     be parked.
         /// </devdoc>
-        internal static void UnparkHandle(HandleRef handle, DpiAwarenessContext context) {
+        internal static void UnparkHandle(HandleRef handle, DpiAwarenessContext? context) {
             ThreadContext cxt = GetContextForHandle(handle);
             if (cxt != null) {
                 cxt.GetParkingWindow(context).UnparkHandle(handle);
@@ -2493,7 +2493,7 @@ internal bool CustomThreadExceptionHandlerAttached {
             ///     if it needs to.
             /// </devdoc>
             /// <internalonly/>
-            internal ParkingWindow GetParkingWindow(DpiAwarenessContext context) {
+            internal ParkingWindow GetParkingWindow(DpiAwarenessContext? context) {
 
                 // Locking 'this' here is ok since this is an internal class.
                 lock(this) {
@@ -2507,7 +2507,6 @@ internal ParkingWindow GetParkingWindow(DpiAwarenessContext context) {
                             Debug.WriteLine(CoreSwitches.PerfTrack.Enabled, Environment.StackTrace);
                         }
 #endif
-
                         using (DpiHelper.EnterDpiAwarenessScope(context)) {
                             parkingWindow = new ParkingWindow();
                         }
@@ -2522,7 +2521,7 @@ internal ParkingWindow GetParkingWindow(DpiAwarenessContext context) {
             /// Returns parking window that matches dpi awareness context. return null if not found.
             /// </summary>
             /// <returns>return matching parking window from list. returns null if not found</returns>
-            internal ParkingWindow GetParkingWindowForContext(DpiAwarenessContext context) {
+            internal ParkingWindow GetParkingWindowForContext(DpiAwarenessContext? context) {
 
                 if (parkingWindows.Count == 0) {
                     return null;
@@ -2531,15 +2530,15 @@ internal ParkingWindow GetParkingWindowForContext(DpiAwarenessContext context) {
                 // Legacy OS/target framework scenario where ControlDpiContext is set to DPI_AWARENESS_CONTEXT.DPI_AWARENESS_CONTEXT_UNSPECIFIED
                 // because of 'ThreadContextDpiAwareness' API unavailability or this feature is not enabled.
 
-                if (!DpiHelper.IsScalingRequirementMet || CommonUnsafeNativeMethods.TryFindDpiAwarenessContextsEqual(context, DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED)) {
+                if (!DpiHelper.IsScalingRequirementMet || DpiUnsafeNativeMethods.TryFindDpiAwarenessContextsEqual(context, null)) {
 
                     Debug.Assert(parkingWindows.Count == 1, "parkingWindows count can not be > 1 for legacy OS/target framework versions");
                     return parkingWindows[0];
                 }
 
                 // Supported OS scenario.
                 foreach (var p in parkingWindows) {
-                    if (CommonUnsafeNativeMethods.TryFindDpiAwarenessContextsEqual(p.DpiAwarenessContext, context)) {
+                    if (DpiUnsafeNativeMethods.TryFindDpiAwarenessContextsEqual(p.DpiAwarenessContext, context)) {
                         return p;
                     }
                 }

src/System.Windows.Forms/src/System/Windows/Forms/Control.cs

@@ -577,7 +577,7 @@ public Control( Control parent, string text, int left, int top, int width, int h
         /// <summary>
         /// gets or sets control Dpi awareness context value.
         /// </summary>
-        internal DpiAwarenessContext DpiAwarenessContext {
+        internal DpiAwarenessContext? DpiAwarenessContext {
             get {
                 return window.DpiAwarenessContext;
             }
@@ -5617,7 +5617,7 @@ protected virtual void CreateHandle() {
                 //
                 if (cp.Parent == IntPtr.Zero && (cp.Style & NativeMethods.WS_CHILD) != 0) {
                     Debug.Assert((cp.ExStyle & NativeMethods.WS_EX_MDICHILD) == 0, "Can't put MDI child forms on the parking form");
-                    Application.ParkHandle(cp);
+                    Application.ParkHandle(cp, window.DpiAwarenessContext);
                 }
 
                 window.CreateHandle(cp);
@@ -5638,6 +5638,11 @@ protected virtual void CreateHandle() {
             }
         }
 
+        protected void ApplicationParkHandleWithWindowContext(HandleRef handle)
+        {
+            Application.ParkHandle(handle, window.DpiAwarenessContext);
+        }
+
         /// <include file='doc\Control.uex' path='docs/doc[@for="Control.CreateControl"]/*' />
         /// <devdoc>
         ///     Forces the creation of the control. This includes the creation of the handle,
@@ -8096,7 +8101,7 @@ internal virtual void  OnParentHandleRecreating() {
 
             // use SetParent directly so as to not raise ParentChanged events
             if (IsHandleCreated) {
-                Application.ParkHandle(new HandleRef(this, this.Handle));
+                Application.ParkHandle(new HandleRef(this, this.Handle), window.DpiAwarenessContext);
             }
         }
 
@@ -11420,7 +11425,7 @@ private void SetParentHandle(IntPtr value) {
                     }
                     if (!GetTopLevel()) {
                         if (value == IntPtr.Zero) {
-                            Application.ParkHandle(new HandleRef(window, Handle));
+                            Application.ParkHandle(new HandleRef(window, Handle), window.DpiAwarenessContext);
                             UpdateRoot();
                         }
                         else {

src/System.Windows.Forms/src/System/Windows/Forms/NativeMethods.cs

@@ -459,6 +459,7 @@ public const int
         public const int E_NOTIMPL = unchecked((int)0x80004001),
         E_OUTOFMEMORY = unchecked((int)0x8007000E),
         E_INVALIDARG = unchecked((int)0x80070057),
+        E_ACCESSDENIED    = unchecked((int)0x80070005),
         E_NOINTERFACE = unchecked((int)0x80004002),
         E_POINTER = unchecked((int)0x80004003),
         E_FAIL = unchecked((int)0x80004005),

src/System.Windows.Forms/src/System/Windows/Forms/NativeWindow.cs

@@ -95,9 +95,9 @@ public class NativeWindow : MarshalByRefObject, IWin32Window {
         NativeWindow previousWindow; // doubly linked list of subclasses.
         NativeWindow nextWindow;
         WeakReference weakThisPtr;
-        private DpiAwarenessContext windowDpiAwarenessContext = DpiHelper.IsScalingRequirementMet ?
-                                                                  CommonUnsafeNativeMethods.TryGetThreadDpiAwarenessContext() :
-                                                                  DpiAwarenessContext.DPI_AWARENESS_CONTEXT_UNSPECIFIED;
+        private DpiAwarenessContext? windowDpiAwarenessContext = DpiHelper.IsScalingRequirementMet ?
+                                                                  (DpiAwarenessContext?)DpiUnsafeNativeMethods.TryGetThreadDpiAwarenessContext() :
+                                                                  null;
 
         static NativeWindow() {
             EventHandler shutdownHandler = new EventHandler(OnShutdown);
@@ -127,7 +127,7 @@ public NativeWindow() {
         /// <summary>
         /// Cache window DpiContext awareness information that helps to create handle with right context at the later time.
         /// </summary>
-        internal DpiAwarenessContext DpiAwarenessContext {
+        internal DpiAwarenessContext? DpiAwarenessContext {
             get {
                 return windowDpiAwarenessContext;
             }

src/System.Windows.Forms/src/System/Windows/Forms/WebBrowserBase.cs

@@ -479,7 +479,7 @@ protected override void WndProc(ref Message m) {
                     if (this.ActiveXState >= WebBrowserHelper.AXState.InPlaceActive) {
                         IntPtr hwndInPlaceObject;
                         if (NativeMethods.Succeeded(this.AXInPlaceObject.GetWindow(out hwndInPlaceObject))) {
-                            Application.ParkHandle(new HandleRef(this.AXInPlaceObject, hwndInPlaceObject));
+                            this.ApplicationParkHandleWithWindowContext(new HandleRef(this.AXInPlaceObject, hwndInPlaceObject));
                         }
                     }