ensure the flyout is closed before opening a new one

Pilz.UI.Telerik/Dialogs/RadFlyoutBase.cs

@@ -1,5 +1,4 @@
 using System.ComponentModel;
-using System.Diagnostics.CodeAnalysis;
 using Telerik.WinControls;
 using Telerik.WinControls.UI;
 
@@ -27,6 +26,8 @@ public partial class RadFlyoutBase : UserControl
     [DefaultValue(true)]
     public bool RegisterDialogCancel { get; set; } = true;
 
+    public new Size PreferredSize { get; set; } = Size.Empty;
+
     [DefaultValue(true)]
     public virtual bool ActionPanelVisible
     {
@@ -224,9 +225,20 @@ public partial class RadFlyoutBase : UserControl
                 frm.AutoSize = true;
                 frm.AutoSizeMode = AutoSizeMode.GrowAndShrink;
             }
+
+            frm.Shown += Form_Shown;
         }
     }
 
+    private void Form_Shown(object? sender, EventArgs e)
+    {
+        if (FindForm() is not Form frm)
+            return;
+
+        if (!AutoSize)
+            frm.ClientSize = PreferredSize;
+    }
+
     protected void Close(DialogResult result)
     {
         Result = result;