Feature: RDP scaling

Author: BornToBeRoot

Source/NETworkManager/Controls/DragablzTabHostWindow.xaml.cs

@@ -212,7 +212,7 @@ private void RemoteDesktop_FullscreenAction(object view)
     private void RemoteDesktop_AdjustScreenAction(object view)
     {
         if (view is RemoteDesktopControl control)
-            control.AdjustScreen();
+            control.AdjustScreen(force:true);
     }
 
     public ICommand RemoteDesktop_SendCtrlAltDelCommand =>

Source/NETworkManager/Controls/IDragablzTabItem.cs

@@ -13,5 +13,6 @@ public interface IDragablzTabItem
     /// </summary>
     public void CloseTab()
     {
+        
     }
 }

Source/NETworkManager/Controls/RemoteDesktopControl.xaml

@@ -9,7 +9,6 @@
                        xmlns:localization="clr-namespace:NETworkManager.Localization.Resources;assembly=NETworkManager.Localization"
                        xmlns:local="clr-namespace:NETworkManager.Controls"
                        xmlns:settings="clr-namespace:NETworkManager.Settings;assembly=NETworkManager.Settings"
-                       xmlns:windowsForms="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"
                        mc:Ignorable="d" Loaded="UserControl_Loaded"                       
                        d:DataContext="{d:DesignInstance local:RemoteDesktopControl}">
     <local:UserControlBase.Resources>

Source/NETworkManager/Controls/RemoteDesktopControl.xaml.cs

@@ -12,7 +12,6 @@
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Input;
-using System.Windows.Threading;
 
 namespace NETworkManager.Controls;
 
@@ -353,48 +352,95 @@ public void FullScreen()
         RdpClient.FullScreen = true;
     }
 
-    public async void AdjustScreen(bool dpiChange = false)
+    public async void AdjustScreen(bool force = false)
     {
-        // Check preconditions
-        if (IsConnecting)
-            return;
-
-        if (!IsConnected)
-            return;
-
-        // Wait for the control to be drawn (if window is resized or the DPI changes)
-        await Task.Delay(250);
-
-        var desktopSize = GetDesktopSize();
-
-        // Check if we need to adjust the screen (always on DPI changes)
-        if (dpiChange == false)
+        try
         {
-            if (RdpClient.DesktopWidth == desktopSize.Item1 && RdpClient.DesktopHeight == desktopSize.Item2)
+            // Check preconditions
+            if (IsConnecting)
             {
-                Debug.WriteLine("==>>> Screen size is already correct.");
+                Log.Debug("AdjustScreen - RDP session is connecting... We can't adjust the screen, yet.");
                 return;
             }
 
-
-            if (RdpClient.Width == desktopSize.Item1 && RdpClient.Height == desktopSize.Item2)
+            if (!IsConnected)
             {
-                Debug.WriteLine("==>>> Screen size is already correct.");
+                Log.Debug("AdjustScreen - RDP session is not connected! We can't adjust the screen.");
                 return;
             }
-        }
 
-        try
-        {
-            Debug.WriteLine("UpdateSessionDisplaySettings...");
+            // Wait for the control to be drawn (if window is resized or the DPI changes)
+            await Task.Delay(250);
+
+            var desktopSize = GetDesktopSize();
+            
+            Log.Debug($"AdjustScreen - Desktop size: {desktopSize.Item1}x{desktopSize.Item2}");
+
+            // Check if we need to adjust the screen (always on DPI changes or manual)
+            if (force == false)
+            {
+                var needUpdate = false;
+                
+                var windowsFormsHostSize = GetWindowsFormsHostSize(desktopSize.Item1, desktopSize.Item2);
+
+                Log.Debug($"AdjustScreen - WindowsFormsHost size: {windowsFormsHostSize.Item1}x{windowsFormsHostSize.Item2}");
+                
+                if (!(Math.Abs(WindowsFormsHostMaxWidth - windowsFormsHostSize.Item1) < double.Epsilon) ||
+                    !(Math.Abs(WindowsFormsHostMaxHeight - windowsFormsHostSize.Item2) < double.Epsilon))
+                {
+                    Log.Debug("AdjustScreen - WindowsFormsHost size is not adjusted!" +
+                              $" Old size: {WindowsFormsHostMaxWidth}x{WindowsFormsHostMaxHeight}, new size: {windowsFormsHostSize.Item1}x{windowsFormsHostSize.Item2}");
+                    needUpdate = true;
+                }
+
+
+                if (!(Math.Abs(RdpClient.Width - desktopSize.Item1) < double.Epsilon) ||
+                    !(Math.Abs(RdpClient.Height - desktopSize.Item2) < double.Epsilon))
+                {
+                    Log.Debug("AdjustScreen - RDP control size is not adjusted!" +
+                              $" Old size: {RdpClient.Width}x{RdpClient.Height}, new size: {desktopSize.Item1}x{desktopSize.Item2}");
+                    needUpdate = true;
+                }
+
+                if (!(Math.Abs(RdpClient.DesktopWidth - desktopSize.Item1) < double.Epsilon) ||
+                    !(Math.Abs(RdpClient.DesktopHeight - desktopSize.Item2) < double.Epsilon))
+                {
+                    Log.Debug("AdjustScreen - RDP session size is not adjusted!" +
+                              $" Old size: {RdpClient.DesktopWidth}x{RdpClient.DesktopHeight}, new size: {desktopSize.Item1}x{desktopSize.Item2}");
+                    needUpdate = true;
+                }
+
+                if (needUpdate)
+                {
+                    Log.Debug("AdjustScreen - Adjusting screen size...");
+                }
+                else
+                {
+                    Log.Debug("AdjustScreen - Screen size is already adjusted!");
+                    return;
+                }
+            }
+            else
+            {
+                Log.Debug("AdjustScreen - Screen size adjustment is forced...");
+            }
+
             // Fix the size of the WindowsFormsHost and the RDP control
             FixWindowsFormsHostSize(desktopSize.Item1, desktopSize.Item2);
-            // This may fail if the RDP session was connected recently
-            RdpClient.UpdateSessionDisplaySettings((uint)desktopSize.Item1, (uint)desktopSize.Item2, (uint)desktopSize.Item1, (uint)desktopSize.Item2, 0, GetDesktopScaleFactor(), GetDeviceScaleFactor());
+            
+            try
+            {
+                // This may fail if the RDP session was connected recently
+                RdpClient.UpdateSessionDisplaySettings((uint)desktopSize.Item1, (uint)desktopSize.Item2, (uint)desktopSize.Item1, (uint)desktopSize.Item2, 0, GetDesktopScaleFactor(), GetDeviceScaleFactor());
+            }
+            catch (Exception ex)
+            {
+                Log.Error("Error while updating the session display settings of the RDP control!", ex);
+            }
         }
-        catch (Exception ex)
+        catch (Exception e)
         {
-            Log.Error("Error while adjusting screen", ex);
+            Log.Error("Could not adjust screen!", e);
         }
     }
 
@@ -406,25 +452,30 @@ public async void AdjustScreen(bool dpiChange = false)
     /// <param name="height">Height of the RDP session.</param>
     private void FixWindowsFormsHostSize(double width, double height)
     {
-        var widthScaled = width / GetDpiScaleFactor() * 100;
-        var heightScaled = height / GetDpiScaleFactor() * 100;
-
-        widthScaled = Math.Ceiling(widthScaled / 2) * 2;
-        heightScaled = Math.Ceiling(heightScaled / 2) * 2;
+        var windowsFormsHostSize = GetWindowsFormsHostSize(width, height);
 
         // Set the max width and height for the WindowsFormsHost
-        WindowsFormsHostMaxWidth = widthScaled;
-        WindowsFormsHostMaxHeight = heightScaled;
+        WindowsFormsHostMaxWidth = windowsFormsHostSize.Item1;
+        WindowsFormsHostMaxHeight = windowsFormsHostSize.Item2;
 
         // Update the size of the RDP control
         RdpClient.Width = (int)width;
         RdpClient.Height = (int)height;
-
-        Debug.WriteLine($"RDP control size: {RdpClient.Width}x{RdpClient.Height}");
-        Debug.WriteLine($"WindowsFormsHost size: {WindowsFormsHostMaxWidth}x{WindowsFormsHostMaxHeight}");
-        Debug.WriteLine($"Values: {width}x{height} - DPI: {GetDpiScaleFactor()}%");
     }
 
+    private Tuple<double, double> GetWindowsFormsHostSize(double width, double height)
+    {
+        var scaleFactor = GetDpiScaleFactor();
+        
+        var widthScaled = width / scaleFactor * 100;
+        var heightScaled = height / scaleFactor * 100;
+
+        widthScaled = Math.Ceiling(widthScaled / 2) * 2;
+        heightScaled = Math.Ceiling(heightScaled / 2) * 2;
+        
+        return new Tuple<double, double>(widthScaled, heightScaled);
+    }
+    
     /// <summary>
     /// Send a keystroke to the remote session.
     /// </summary>
@@ -575,25 +626,17 @@ private static string GetDisconnectReason(int reason)
     /// https://cdnweb.devolutions.net/blog/pdf/smart-resizing-and-high-dpi-issues-in-remote-desktop-manager.pdf
     /// </summary>
     /// <returns></returns>
-    protected uint GetDesktopScaleFactor()
+    private uint GetDesktopScaleFactor()
     {
         var scaleFactor = GetDpiScaleFactor();
 
-        switch (scaleFactor)
+        return scaleFactor switch
         {
-            case 125:
-                return 125;
-            case 150:
-            case 175:
-                return 150;
-            case 200:
-                return 200;
-        }
-
-        if (scaleFactor > 200)
-            return 200;
-
-        return 100;
+            125 => 125,
+            150 or 175 => 150,
+            200 => 200,
+            _ => (uint)(scaleFactor > 200 ? 200 : 100)
+        };
     }
 
     /// <summary>
@@ -604,7 +647,7 @@ protected uint GetDesktopScaleFactor()
     /// https://cdnweb.devolutions.net/blog/pdf/smart-resizing-and-high-dpi-issues-in-remote-desktop-manager.pdf
     /// </summary>
     /// <returns>Device scale factor.</returns>
-    protected uint GetDeviceScaleFactor()
+    private uint GetDeviceScaleFactor()
     {
         var scaleFactor = GetDpiScaleFactor();
 
@@ -628,7 +671,7 @@ protected uint GetDeviceScaleFactor()
     /// Get the current DPI scale factor like 100, 125, 150, 175, 200, 225, etc.
     /// </summary>
     /// <returns>Returns the DPI scale factor.</returns>
-    public int GetDpiScaleFactor()
+    private int GetDpiScaleFactor()
     {
         var x = System.Windows.Media.VisualTreeHelper.GetDpi(this);
 
@@ -655,15 +698,12 @@ private void RdpClient_OnDisconnected(object sender, IMsTscAxEvents_OnDisconnect
 
     public void UpdateOnWindowResize()
     {
-
-        Debug.WriteLine("UpdateOnWindowResize...");
-
         if (_sessionInfo.AdjustScreenAutomatically)
             AdjustScreen();
     }
 
     private void WindowsFormsHost_DpiChanged(object sender, DpiChangedEventArgs e)
     {
-        AdjustScreen(dpiChange: true);
+        AdjustScreen(force: true);
     }
 }

Source/NETworkManager/ViewModels/RemoteDesktopHostViewModel.cs

@@ -281,7 +281,7 @@ private void FullscreenAction(object view)
     private void AdjustScreenAction(object view)
     {
         if (view is RemoteDesktopControl control)
-            control.AdjustScreen();
+            control.AdjustScreen(force:true);
     }
 
     public ICommand SendCtrlAltDelCommand => new RelayCommand(SendCtrlAltDelAction, IsConnected_CanExecute);

Website/docs/changelog/next-release.md

@@ -17,7 +17,9 @@ Release date: **xx.xx.2024**
 
 ## Breaking Changes
 
-- Minimum supported Windows version increased to `22H2`. [#2912](https://github.com/BornToBeRoot/NETworkManager/pull/2912)
+- Minimum supported Windows version increased to `22H2` to support:
+  - WiFi 6 GHz, WPA3, 802.11be [#2912](https://github.com/BornToBeRoot/NETworkManager/pull/2912)
+  - Remote Desktop high DPI, scaling and resizing [#2968](https://github.com/BornToBeRoot/NETworkManager/pull/2968)
 
 ## What's new?
 
@@ -27,6 +29,17 @@ Release date: **xx.xx.2024**
   - `WPA3 Personal (SAE)`, `WPA3 Enterprise` and `WPA3 Enterprise (192-bit)` are now supported. [#2912](https://github.com/BornToBeRoot/NETworkManager/pull/2912)
   - `802.11be` (`EHT`) is now supported. [#2912](https://github.com/BornToBeRoot/NETworkManager/pull/2912)
 
+- **Remote Desktop**
+
+  - Scale rdp session and control to support high DPI (e.g. per Monitor DPI like 125%, 150%, etc.). [#2968](https://github.com/BornToBeRoot/NETworkManager/pull/2968)
+  - Resizing now uses [`IMsRdpClient9::UpdateSessionDisplaySettings`](<https://learn.microsoft.com/en-us/previous-versions/windows/desktop/legacy/mt703457(v=vs.85)>) instead of [`IMsRdpClient::Reconnect`](https://learn.microsoft.com/en-us/windows/win32/termserv/imsrdpclient8-reconnect) to support scaling and faster resizing (without the need of reconnecting). [#2968](https://github.com/BornToBeRoot/NETworkManager/pull/2968).
+
+  :::warning
+
+  The new features for high DPI, scaling and resizing may cause issues or doesn't work with legacy servers/clients. Please report any issues you find here: [#2911](https://github.com/BornToBeRoot/NETworkManager/issues/2911)
+
+  :::
+
 ## Improvements
 
 - Improve ToolTips (e.g. migrate from Twitter to X, etc.), Buttons, etc. [#2955](https://github.com/BornToBeRoot/NETworkManager/pull/2955)