* Touchscreen High DPI scaling

Documents/Changelog/Changelog.md

@@ -4,6 +4,8 @@
 
 ## 2026-11-xx - Build 2611 (V110 Nightly) - November 2026
 
+* Resolved/Implemented [#2844](https://github.com/Krypton-Suite/Standard-Toolkit/issues/2844), Touchscreen High DPI scaling
+* Implemented [#2808](https://github.com/Krypton-Suite/Standard-Toolkit/issues/2808), Move `KryptonToastNotification` feature to `Krypton.Utilities`
 * Implemented [#2572](https://github.com/Krypton-Suite/Standard-Toolkit/issues/2572), Autocomplete control/menu
 	- To use, you will need to download the `Krypton.Standard.Toolkit` NuGet package, as this control is part of the `Krypton.Utilities` assembly.
 * Implemented [#2812](https://github.com/Krypton-Suite/Standard-Toolkit/issues/2812), Code Editor Control

Source/Krypton Components/Krypton.Toolkit/Controls Visuals/VisualForm.cs

@@ -1931,6 +1931,45 @@ private void OnJumpListChanged()
 
     private void UpdateDpiFactors()
     {
+        // Invalidate the global DPI cache to ensure fresh values are calculated
+        KryptonManager.InvalidateDpiCache();
+
+        // Use per-monitor DPI for proper high DPI and touchscreen scaling support
+        IntPtr hWnd = IsHandleCreated ? Handle : IntPtr.Zero;
+
+        if (hWnd != IntPtr.Zero)
+        {
+            try
+            {
+                // Try to use GetDpiForWindow for per-monitor DPI awareness (Windows 10 version 1607+)
+                uint dpi = PI.GetDpiForWindow(hWnd);
+                if (dpi > 0)
+                {
+                    FactorDpiX = dpi / 96f;
+                    FactorDpiY = dpi / 96f;
+                    return;
+                }
+            }
+            catch
+            {
+                // GetDpiForWindow may not be available on older Windows versions
+            }
+
+            // Fallback to window's Graphics DPI
+            try
+            {
+                using Graphics graphics = Graphics.FromHwnd(hWnd);
+                FactorDpiX = graphics.DpiX / 96f;
+                FactorDpiY = graphics.DpiY / 96f;
+                return;
+            }
+            catch
+            {
+                // Continue to primary monitor fallback
+            }
+        }
+
+        // Fallback
         // Do not use the control dpi, as these values are being used to target the screen
         IntPtr screenDc = PI.GetDC(IntPtr.Zero);
         if (screenDc != IntPtr.Zero)

Source/Krypton Components/Krypton.Toolkit/View Base/ViewBase.cs

@@ -240,6 +240,53 @@ public float FactorDpiX
 
     private void InitialiseFactors()
     {
+        // Try to get per-monitor DPI from the owning control for proper high DPI support
+        Control? owningControl = OwningControl;
+        IntPtr hWnd = IntPtr.Zero;
+
+        if (owningControl != null && owningControl.IsHandleCreated)
+        {
+            hWnd = owningControl.Handle;
+        }
+        else if (Component is Control componentControl && componentControl.IsHandleCreated)
+        {
+            hWnd = componentControl.Handle;
+        }
+
+        // Use per-monitor DPI if we have a window handle (supports high DPI and touchscreen scaling)
+        if (hWnd != IntPtr.Zero)
+        {
+            try
+            {
+                // Try to use GetDpiForWindow for per-monitor DPI awareness (Windows 10 version 1607+)
+                uint dpi = PI.GetDpiForWindow(hWnd);
+                if (dpi > 0)
+                {
+                    _factorDpiX = dpi / 96f;
+                    _factorDpiY = dpi / 96f;
+                    return;
+                }
+            }
+            catch
+            {
+                // GetDpiForWindow may not be available on older Windows versions
+            }
+
+            // Fallback to window's Graphics DPI
+            try
+            {
+                using Graphics graphics = Graphics.FromHwnd(hWnd);
+                _factorDpiX = graphics.DpiX / 96f;
+                _factorDpiY = graphics.DpiY / 96f;
+                return;
+            }
+            catch
+            {
+                // Continue to primary monitor fallback
+            }
+        }
+
+        // Fallback
         // This does mean that the app will not change it's dpi awareness until restarted !
         // Do not use the control dpi, as these values are being used to target the screen
         var screenDc = PI.GetDC(IntPtr.Zero);
@@ -274,6 +321,16 @@ public float FactorDpiY
         }
     }
 
+    /// <summary>
+    /// Invalidates the cached DPI factors, forcing them to be recalculated on the next access.
+    /// Call this method when the DPI changes (e.g., when the window is moved to a different monitor).
+    /// </summary>
+    public void InvalidateDpiFactors()
+    {
+        _factorDpiX = 0f;
+        _factorDpiY = 0f;
+    }
+
     #endregion
 
     #region Component

Source/Krypton Components/TestForm/StartScreen.cs

@@ -84,6 +84,7 @@ private void AddButtons()
         CreateButton("Taskbar Overlay Icon Test", "Comprehensive demonstration of taskbar overlay icons on KryptonForm with configurable icons, descriptions, and interactive examples.", typeof(TaskbarOverlayIconTest));
         CreateButton("Theme Controls", string.Empty, typeof(ThemeControlExamples));
         CreateButton("TextBox Validating Test", "Tests fix for Validating event duplication bug #2801", typeof(KryptonTextBoxValidatingTest));
+        CreateButton("Touchscreen + High DPI Demo", "Comprehensive demonstration of touchscreen support with per-monitor high DPI scaling (Issue #2844).", typeof(TouchscreenHighDpiDemo));
         CreateButton("RichTextBox Formatting Test", "Tests fix for RichTextBox formatting preservation when palette changes (Issue #2832)", typeof(RichTextBoxFormattingTest));
         CreateButton("RTL Layout Test", "Test for RTL compliance", typeof(RTLFormBorderTest));
         CreateButton("Toast", "For breakfast....?", typeof(ToastNotificationTestChoice));