2914-V105-LTS-White bar is shown in a KryptonForm Sizable without buttons and text

Source/Krypton Components/Krypton.Toolkit/Controls Toolkit/KryptonForm.cs

@@ -2046,7 +2046,7 @@ protected override void OnHandleCreated(EventArgs e)
     protected override void WindowChromeStart()
     {
         // Make sure the views for the buttons are created
-        if (_recreateButtons)
+        if (_recreateButtons && this.ControlBox && !string.IsNullOrWhiteSpace(this.Text))
         {
             _buttonManager.RecreateButtons();
             _recreateButtons = false;
@@ -3322,5 +3322,49 @@ public static bool GetIsInAdministratorMode()
 
         return _isInAdministratorMode;
     }
-    #endregion
+	#endregion
+
+
+	/// <summary>
+	/// Determines whether the KryptonForm has usable caption content
+	/// for non-client painting (Text / TextExtra and chrome-aware).
+	/// </summary>
+	protected override bool HasCaptionContent()
+	{
+		// No border => no non-client caption at all
+		if (FormBorderStyle == FormBorderStyle.None)
+		{
+			return false;
+		}
+
+		// No visible caption content
+		bool hasCaptionText =
+			!string.IsNullOrWhiteSpace(Text) ||
+			!string.IsNullOrWhiteSpace(TextExtra);
+
+		if (!hasCaptionText)
+		{
+			return false;
+		}
+
+		// Edge-case:
+		// When ControlBox is false and caption content is minimal,
+		// avoid treating the caption as usable to prevent
+		// non-client artifacts (e.g. white bar on deactivate).
+		if (!ControlBox && string.IsNullOrWhiteSpace(TextExtra))
+		{
+			return false;
+		}
+
+		return FormBorderStyle switch
+		{
+			FormBorderStyle.FixedSingle => true,
+			FormBorderStyle.Fixed3D => true,
+			FormBorderStyle.FixedDialog => true,
+			FormBorderStyle.Sizable => true,
+			FormBorderStyle.FixedToolWindow => true,
+			FormBorderStyle.SizableToolWindow => true,
+			_ => false
+		};
+	}
 }

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

@@ -777,8 +777,14 @@ protected void InvalidateNonClient(Rectangle invalidRect, bool excludeClientArea
             {
                 hRgn = invalidRegion.GetHrgn(g);
 
+                if (!HasCaptionContent())
+                    this.SuspendPaint();
+
                 PI.RedrawWindow(Handle, IntPtr.Zero, hRgn.Value,
                     PI.RDW_FRAME | PI.RDW_UPDATENOW | PI.RDW_INVALIDATE);
+
+				if (!HasCaptionContent())
+					this.ResumePaint();
             }
             catch (InvalidOperationException ioEx)
             {
@@ -795,10 +801,25 @@ protected void InvalidateNonClient(Rectangle invalidRect, bool excludeClientArea
         }
     }
 
-    /// <summary>
-    /// Gets rectangle that is the real window rectangle based on Win32 API call.
-    /// </summary>
-    protected Rectangle RealWindowRectangle
+	/// <summary>
+	/// Determines whether the form has a native non-client frame with a usable caption.
+	/// 
+	/// This method must be overridden by derived classes that provide
+	/// a concrete implementation of form chrome handling.
+	/// </summary>
+	/// <exception cref="NotSupportedException">
+	/// Thrown when the method is not overridden in a derived class.
+	/// </exception>
+	protected virtual bool HasCaptionContent()
+	{
+		throw new NotSupportedException(
+			$"{GetType().Name} must override HasCaptionContent() to provide a valid implementation.");
+	}
+
+	/// <summary>
+	/// Gets rectangle that is the real window rectangle based on Win32 API call.
+	/// </summary>
+	protected Rectangle RealWindowRectangle
     {
         get
         {

Source/Krypton Components/TestForm/Bug2914Test.cs

@@ -16,4 +16,68 @@ public Bug2914Test()
     {
         InitializeComponent();
     }
+
+	private void Bug2914Test_Load(object sender, EventArgs e)
+	{
+
+	}
+
+	// Event handler for kryptonButton1 click
+	// Opens the Bug2914Test form as a modal dialog with no title bar text
+	// and without the system control buttons (minimize, maximize, close).
+	private void kryptonButton1_Click(object sender, EventArgs e)
+	{
+		// Create a new instance of the Bug2914Test form
+		Bug2914Test frm = new Bug2914Test();
+
+		// Center the form on the screen when it is shown
+		frm.StartPosition = FormStartPosition.Manual;
+
+		// Explicitly set the location (redundant when using CenterScreen,
+		// but kept for consistency or testing purposes)
+		frm.Location = new Point(0, 0);
+
+		// Remove the window title text
+		frm.Text = string.Empty;
+
+		// Allow the form to be resized
+		frm.FormBorderStyle = FormBorderStyle.Sizable;
+
+		// Disable the control box (Close, Minimize, Maximize buttons)
+		frm.ControlBox = false;
+
+		// Show the form as a modal dialog
+		frm.ShowDialog();
+	}
+
+	// Event handler for kryptonButton2 click
+	// Closes the current form.
+	private void kryptonButton2_Click(object sender, EventArgs e)
+	{
+		// Close the current window
+		this.Close();
+	}
+
+	// Event handler for kryptonButton3 click
+	// Opens the Bug2914Test form as a modal dialog with a visible title.
+	private void kryptonButton3_Click(object sender, EventArgs e)
+	{
+		// Create a new instance of the Bug2914Test form
+		Bug2914Test frm = new Bug2914Test();
+
+		// Center the form on the screen
+		frm.StartPosition = FormStartPosition.CenterScreen;
+
+		// Set the initial position of the form
+		frm.Location = new Point(0, 0);
+
+		// Set the window title text
+		frm.Text = "HOLA";
+
+		// Allow the form to be resized
+		frm.FormBorderStyle = FormBorderStyle.Sizable;
+
+		// Show the form as a modal dialog
+		frm.ShowDialog();
+	}
 }

Source/Krypton Components/TestForm/Bug2914Test.resx

@@ -117,4 +117,7 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
+  <metadata name="kryptonManager1.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+    <value>17, 17</value>
+  </metadata>
 </root>