Update CustomSwitch.xaml.cs

[gchapeaux]

I met an exception when using a Style dictionary to style CustomSwitchs, with KnobFrame and BackgroundFrame being null when SizeRequestChanged is called for the first time. Adding HasLoaded in the check at the beginning of the method seems to fix this issue.

[IeuanWalker]

@gchapeaux can you provide an a repo of the issue please

[gchapeaux]

Hello @IeuanWalker,
I created a minimal project with the issue happening : MRE_Sandbox_9. The Style is defined in Resources > Styles, and from when I tried working on it from the main project I'm working on right now, I ended up finding the issue was caused by KnobFrame being null when SizeRequestChanged is called for the first time.

The beginning of the exception I get :

10:08:50:237	[mono-rt] [ERROR] FATAL UNHANDLED EXCEPTION: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
10:08:50:237	[mono-rt]  ---> System.NullReferenceException: Object reference not set to an instance of an object.
10:08:50:237	[mono-rt]    at IeuanWalker.Maui.Switch.CustomSwitch.SizeRequestChanged(BindableObject bindable, Object oldValue, Object newValue)
10:08:50:237	[mono-rt]    at Microsoft.Maui.Controls.BindableObject.OnBindablePropertySet(BindableProperty property, Object original, Object value, Boolean didChange, Boolean willFirePropertyChanged) in /_/src/Controls/src/Core/BindableObject.cs:line 675
10:08:50:237	[mono-rt]    at Microsoft.Maui.Controls.Element.OnBindablePropertySet(BindableProperty property, Object original, Object value, Boolean changed, Boolean willFirePropertyChanged) in /_/src/Controls/src/Core/Element/Element.cs:line 642