The "InheritedGlyph" icon cannot be show in Inherited control

[LeafShi1]

In Demo project, the InheritedGlyph icon doesn't show in inherited control CustomButton

Expected:
1 Create a form with a button - Form1
2. Build the app
3. Create a form that inherits from Form1
4. The "InheritedGlyph" icon show on the inherited control

[elachlan]

Debugging this when we hit this code for the CustomButton the Inherited value is false

winforms/src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/ControlDesigner.cs

Lines 984 to 989 in 2ac220c

	// If we are an inherited control, notify our inheritance UI
	if (Inherited && _host is not null && _host.RootComponent != component)
	{
	_inheritanceUI = GetService<InheritanceUI>();
	_inheritanceUI?.AddInheritedControl(Control, InheritanceAttribute.InheritanceLevel);
	}

Inherited ends up calling ComponentDesigner.InheritanceAttribute, getting the attribute from the InheritanceService

winforms/src/System.Windows.Forms.Design/src/System/ComponentModel/Design/ComponentDesigner.cs

Lines 87 to 109 in 2ac220c

	/// <summary>
	/// Gets the inheritance attribute for this component.
	/// </summary>
	protected virtual InheritanceAttribute? InheritanceAttribute
	{
	get
	{
	if (_inheritanceAttribute is null)
	{
	// Record if this component is being inherited or not.
	if (TryGetService(out IInheritanceService? inheritanceService))
	{
	_inheritanceAttribute = inheritanceService.GetInheritanceAttribute(Component);
	}
	else
	{
	_inheritanceAttribute = InheritanceAttribute.Default;
	}
	}
	return _inheritanceAttribute;
	}
	}

winforms/src/System.Windows.Forms.Design/src/System/ComponentModel/Design/InheritanceService.cs

Lines 254 to 260 in 2ac220c

	/// <summary>
	/// Gets the inheritance attribute of the specified component.
	/// </summary>
	public InheritanceAttribute GetInheritanceAttribute(IComponent component)
	=> _inheritedComponents.TryGetValue(component, out InheritanceAttribute? attr)
	? attr
	: InheritanceAttribute.Default;

It looks like InheritanceService.AddInheritedComponents is called when the rootComponent is being initialized on the MainForm. I am having trouble understanding how it is supposed to add each component, because it adds a handler to the IComponentChangeService.ComponentAdding and then removes it at the end of the AddInheritedComponents method.

[merriemcgaw]

@elachlan thanks for helping us pinpoint this! I don't think it's top priority at the moment, until there is a customer that needs the feature. That is unless you have a strong desire to add a PR for it 😉

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Happy Coding!