WI01087620: Add reflection-free protected static API for ZBindingContext net10 compatibility

src/System.Windows.Forms.Legacy/System.Windows.Forms.Package/System.Windows.Forms.Package.csproj

@@ -10,6 +10,7 @@
     <WtgPackageVersionPrefix>0.1.0</WtgPackageVersionPrefix>
     <PackageVersion Condition="'$(PackageVersion)' == ''">$(WtgPackageVersionPrefix)-dev</PackageVersion>
     <PackageDescription>WiseTech Global forked version of System.Windows.Forms that includes controls that were deprecated in .NET Core 3.1 and .NET 5, like DataGrid, Menu, ToolBar and StatusBar.</PackageDescription>
+    <PackageReleaseNotes>HotFix - Fix ZBindingContext related-manager binding behavior on .NET 10</PackageReleaseNotes>
     <Authors>WiseTech Global</Authors>
     <Copyright>© WiseTech Global Limited. All rights reserved.</Copyright>
     <PackageReadmeFile>README.md</PackageReadmeFile>

src/System.Windows.Forms/PublicAPI.Unshipped.txt

@@ -22,7 +22,11 @@ System.Windows.Forms.SystemColorMode.Classic = 0 -> System.Windows.Forms.SystemC
 System.Windows.Forms.SystemColorMode.Dark = 2 -> System.Windows.Forms.SystemColorMode
 System.Windows.Forms.SystemColorMode.System = 1 -> System.Windows.Forms.SystemColorMode
 System.Windows.Forms.VisualStyles.ComboBoxState.Focused = 5 -> System.Windows.Forms.VisualStyles.ComboBoxState
-static System.Windows.Forms.BindingContext.RewireRelatedCurrencyManagerParent(System.Windows.Forms.BindingManagerBase! bindingManagerBase) -> void
+static System.Windows.Forms.BindingContext.DetachRelatedManagerFromParentItemChanged(System.Windows.Forms.BindingManagerBase! bindingManagerBase) -> void
+static System.Windows.Forms.BindingContext.GetParentCurrencyManager(System.Windows.Forms.BindingManagerBase! bindingManagerBase) -> System.Windows.Forms.CurrencyManager?
+static System.Windows.Forms.BindingContext.RaiseCurrentItemChangedSuppressingPushData(System.Windows.Forms.CurrencyManager! currencyManager, System.EventArgs! e) -> void
+static System.Windows.Forms.BindingContext.RefreshRelatedManagerFromParent(System.Windows.Forms.BindingManagerBase! bindingManagerBase) -> void
+static System.Windows.Forms.BindingContext.ResetRelatedManagerToEmptyList(System.Windows.Forms.BindingManagerBase! bindingManagerBase, System.Collections.IList! emptyList) -> void
 virtual System.Windows.Forms.BindingContext.OnListManagerAdded(System.Windows.Forms.BindingManagerBase! bindingManagerBase) -> void
 virtual System.Windows.Forms.Form.OnFormBorderColorChanged(System.EventArgs! e) -> void
 virtual System.Windows.Forms.Form.OnFormCaptionBackColorChanged(System.EventArgs! e) -> void

src/System.Windows.Forms/System/Windows/Forms/DataBinding/BindingContext.cs

@@ -305,20 +305,49 @@ protected virtual void OnListManagerAdded(BindingManagerBase bindingManagerBase)
     }
 
     /// <summary>
-    ///  Helper for subclasses overriding <see cref="OnListManagerAdded"/>: if the supplied manager is a
-    ///  child currency manager, detaches its parent's <see cref="BindingManagerBase.CurrentItemChanged"/>
-    ///  subscription and re-attaches it to <see cref="BindingManagerBase.CurrentChanged"/>, then primes the child
-    ///  once with the parent's current state. No-op for managers that are not <see cref="RelatedCurrencyManager"/>
-    ///  instances. Exposed because <see cref="RelatedCurrencyManager"/> is internal and cannot be referenced from
-    ///  subclasses in other assemblies.
+    ///  Helper for subclasses overriding <see cref="OnListManagerAdded"/>: returns the parent
+    ///  <see cref="CurrencyManager"/> that drives the supplied related (child) currency manager, or
+    ///  <see langword="null"/> when the manager is top-level or is not a child currency manager. Lets subclasses
+    ///  re-wire parent/child change notifications without reflecting over the internal
+    ///  <see cref="RelatedCurrencyManager"/> type.
     /// </summary>
-    protected static void RewireRelatedCurrencyManagerParent(BindingManagerBase bindingManagerBase)
-    {
-        if (bindingManagerBase is RelatedCurrencyManager relatedCurrencyManager)
-        {
-            relatedCurrencyManager.RewireParentChangeHandler();
-        }
-    }
+    protected static CurrencyManager? GetParentCurrencyManager(BindingManagerBase bindingManagerBase)
+        => (bindingManagerBase as RelatedCurrencyManager)?.ParentCurrencyManager;
+
+    /// <summary>
+    ///  Helper for subclasses overriding <see cref="OnListManagerAdded"/>: detaches the default
+    ///  <see cref="BindingManagerBase.CurrentItemChanged"/> subscription that a child currency manager wires onto
+    ///  its parent, so the subclass can drive the child from the parent's
+    ///  <see cref="BindingManagerBase.CurrentChanged"/> event instead. No-op for managers that are not
+    ///  <see cref="RelatedCurrencyManager"/> instances.
+    /// </summary>
+    protected static void DetachRelatedManagerFromParentItemChanged(BindingManagerBase bindingManagerBase)
+        => (bindingManagerBase as RelatedCurrencyManager)?.DetachParentItemChangedHandler();
+
+    /// <summary>
+    ///  Helper for subclasses overriding <see cref="OnListManagerAdded"/>: refreshes a child currency manager's
+    ///  list from its parent's current row, exactly as the default CurrentItemChanged handler would. No-op for
+    ///  managers that are not <see cref="RelatedCurrencyManager"/> instances.
+    /// </summary>
+    protected static void RefreshRelatedManagerFromParent(BindingManagerBase bindingManagerBase)
+        => (bindingManagerBase as RelatedCurrencyManager)?.RefreshFromParentCurrent();
+
+    /// <summary>
+    ///  Helper for subclasses overriding <see cref="OnListManagerAdded"/>: resets a child currency manager to the
+    ///  supplied empty placeholder list and raises position/current change events, without running the
+    ///  AddNew/CancelCurrentEdit appcompat path that the default empty-parent handling uses. No-op for managers
+    ///  that are not <see cref="RelatedCurrencyManager"/> instances.
+    /// </summary>
+    protected static void ResetRelatedManagerToEmptyList(BindingManagerBase bindingManagerBase, IList emptyList)
+        => (bindingManagerBase as RelatedCurrencyManager)?.ResetToEmptyList(emptyList);
+
+    /// <summary>
+    ///  Helper for subclasses: raises <see cref="BindingManagerBase.CurrentItemChanged"/> on a currency manager
+    ///  while suppressing the push of data back into bound controls, so the subclass can notify bindings that the
+    ///  current item has gone (position -1) without WinForms trying to push data into a row that no longer exists.
+    /// </summary>
+    protected static void RaiseCurrentItemChangedSuppressingPushData(CurrencyManager currencyManager, EventArgs e)
+        => currencyManager.RaiseCurrentItemChangedSuppressingPushData(e);
 
     private static void CheckPropertyBindingCycles(BindingContext newBindingContext, Binding propBinding)
     {

src/System.Windows.Forms/System/Windows/Forms/DataBinding/CurrencyManager.cs

@@ -880,6 +880,25 @@ protected internal override void OnCurrentItemChanged(EventArgs e)
         _onCurrentItemChangedHandler?.Invoke(this, e);
     }
 
+    // WiseTech: raises CurrentItemChanged while suppressing the push of data back into bound controls, so callers
+    // can notify bindings that the current item has gone (position -1) without WinForms trying to push data into a
+    // row that no longer exists. Preserves the previous suspension flag. Used by ZBindingContext on .NET 10 in
+    // place of the .NET Framework reflection that toggled the removed suspendPushDataInCurrentChanged field.
+    internal void RaiseCurrentItemChangedSuppressingPushData(EventArgs e)
+    {
+        bool previouslySuppressed = _state.HasFlag(CurrencyManagerStates.SuspendPushDataInCurrentChanged);
+        _state.ChangeFlags(CurrencyManagerStates.SuspendPushDataInCurrentChanged, true);
+
+        try
+        {
+            OnCurrentItemChanged(e);
+        }
+        finally
+        {
+            _state.ChangeFlags(CurrencyManagerStates.SuspendPushDataInCurrentChanged, previouslySuppressed);
+        }
+    }
+
     protected virtual void OnItemChanged(ItemChangedEventArgs e)
     {
         // It is possible that CurrencyManager_PushData will change the position

src/System.Windows.Forms/System/Windows/Forms/DataBinding/RelatedCurrencyManager.cs

@@ -138,22 +138,55 @@
     // WiseTech: RelatedCurrencyManager normally refreshes its child list whenever the parent manager raises
     // CurrentItemChanged. In CargoWise that can be too broad: item-change notifications may be raised while
     // bindings/business collections are already reacting to the same edit or AddNew flow, and refreshing the
-    // child list from that path can re-enter the same notification chain until the stack overflows. ZBindingContext
-    // avoided this on .NET Framework by intercepting BindingContextHashtable.Add, removing the default
-    // CurrentItemChanged subscription, and refreshing the child only when the parent's CurrentChanged event fires.
-    // BindingContext uses a Dictionary on .NET 10, so this helper gives subclasses the same event swap without
-    // reflecting over RelatedCurrencyManager internals.
-    internal void RewireParentChangeHandler()
+    // child list from that path can re-enter the same notification chain until the stack overflows. Worse, the
+    // default empty-parent branch of ParentManager_CurrentItemChanged runs an AddNew/CancelCurrentEdit appcompat
+    // dance which, against a CargoWise business-object collection, actually adds and then deletes a real business
+    // object. ZBindingContext avoided this on .NET Framework by intercepting BindingContextHashtable.Add, removing
+    // the default CurrentItemChanged subscription, and driving the child from the parent's CurrentChanged event
+    // with CargoWise-owned policy (skip redundant refreshes; reset to a safe empty list instead of AddNew/Cancel).
+    // BindingContext uses a Dictionary on .NET 10, so the members below give that subclass the same mechanism
+    // (parent lookup, handler detach, refresh, safe empty reset) without reflecting over RelatedCurrencyManager
+    // internals. The when-to-refresh policy stays in ZBindingContext because it depends on CargoWise types.
+
+    /// <summary>
+    ///  The parent currency manager that drives this child, or <see langword="null"/> when the parent is not a
+    ///  <see cref="CurrencyManager"/>.
+    /// </summary>
+    internal CurrencyManager? ParentCurrencyManager => _parentManager as CurrencyManager;
+
+    /// <summary>
+    ///  Detaches the default <see cref="ParentManager_CurrentItemChanged"/> subscription that <see cref="Bind"/>
+    ///  wired onto the parent. Callers that drive the child from the parent's CurrentChanged event use this to
+    ///  avoid double refreshing.
+    /// </summary>
+    internal void DetachParentItemChangedHandler()
     {
-        if (_parentManager is CurrencyManager parentCurrencyManager)
+        if (_parentManager is not null)
         {
-            parentCurrencyManager.CurrentItemChanged -= ParentManager_CurrentItemChanged;
-            parentCurrencyManager.CurrentChanged -= ParentManager_CurrentItemChanged;
-            parentCurrencyManager.CurrentChanged += ParentManager_CurrentItemChanged;
-            ParentManager_CurrentItemChanged(parentCurrencyManager, EventArgs.Empty);
+            _parentManager.CurrentItemChanged -= ParentManager_CurrentItemChanged;
         }
     }
 
+    /// <summary>
+    ///  Refreshes the child list from the parent's current row, exactly as the default CurrentItemChanged handler
+    ///  does.
+    /// </summary>
+    internal void RefreshFromParentCurrent() => ParentManager_CurrentItemChanged(_parentManager, EventArgs.Empty);
+
+    /// <summary>
+    ///  Resets this child to the supplied empty placeholder list and raises position/current change notifications,
+    ///  bypassing the AddNew/CancelCurrentEdit appcompat path that <see cref="ParentManager_CurrentItemChanged"/>
+    ///  runs when the parent is empty.
+    /// </summary>
+    internal void ResetToEmptyList(IList emptyList)
+    {
+        SetDataSource(emptyList);
+        listposition = -1;
+        OnPositionChanged(EventArgs.Empty);
+        OnCurrentChanged(EventArgs.Empty);
+        OnCurrentItemChanged(EventArgs.Empty);
+    }
+
     private void ParentManager_CurrentItemChanged(object? sender, EventArgs e)
     {
         if (IgnoreItemChangedTable.Contains(_parentManager))