Element.OnChildRemoved() - Incorrect variable used in function.

[Martyf101]

Wrong variable in function call prevents retrieving required information:

ChildRemoved?.Invoke(child, new ElementEventArgs(child));

The first parameter should be "this" not "child", as its already in the second parameters EventArgs and not the sender.

Here is the ChildAdded line for comparison, with the correct parameters:

ChildAdded?.Invoke(this, new ElementEventArgs(child));

Element.cs lines 344-370 :

`

	protected virtual void OnChildAdded(Element child)
	{
		child.Parent = this;

		child.ApplyBindings(skipBindingContext: false, fromBindingContextChanged: true);

		ChildAdded?.Invoke(this, new ElementEventArgs(child));

		VisualDiagnostics.OnChildAdded(this, child);

		OnDescendantAdded(child);
		foreach (Element element in child.Descendants())
			OnDescendantAdded(element);
	}

	protected virtual void OnChildRemoved(Element child, int oldLogicalIndex)
	{
		child.Parent = null;

		ChildRemoved?.Invoke(child, new ElementEventArgs(child));

		VisualDiagnostics.OnChildRemoved(this, child, oldLogicalIndex);

		OnDescendantRemoved(child);
		foreach (Element element in child.Descendants())
			OnDescendantRemoved(element);
	}`

The following call throws "Specified cast is not valid." error as the sender is incorrectly set.

childPage.ChildRemoved += (s, e) => System.Diagnostics.Debug.WriteLine(((NavigationPage)s).Height);

Element.cs Line 363 should be written as:

ChildRemoved?.Invoke(this, new ElementEventArgs(child));

[ghost]

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[hartez]

This was fixed in November: f9c7e4d

What branch are you seeing this on?

[Martyf101]

Okay I can see this is fixed now on main branch. I would have got there though the search/reference popup on GitHub.

However it is still sending 'child' in the version I'm running, and I appear to be fully updated : 6.0.548

childPage.ChildRemoved += (s, e) => { if (s == e.Element) System.Diagnostics.Debug.WriteLine("SENDER EQUALS ELEMENT"); }

Shouldn't this code already be in the released version?

[hartez]

It's been backported to 7.0 and will be in the next 7.0 service release (which should be coming soon). It has not been backported to 6.0 and there are currently no plans to do so.