xaml设计时需要实例还是避免实例？

Question

I have a problem I can not find how to solve the issue of the Design-time XAML, because it tells me: " Object reference not set an instance of an object ".

Visual capture:

Here my fill of the list from Partial Class MainPage:

However, at compile time, it works correctly:

And after runtime, it works....

And my namespace of ViewModels where load return the list of " Scenario " class, instantiate not testify again as only get it built above. And I want to instantiate all my MainPage XAML when I just need a static list.

Any way to solve this without instantiating the list in the constructor? Or what good practice recommend? I want to work in Design-Time.

EDIT: To clarify, in the class: MainPage my control: MainWindow (sealed class, the capture is the partial kind of my sealed class) is where I think my static variable of type " MainPage ", with the builder to " this " and that let me get elements.

Thousand Thanks.

Answer 1

Has MainPage.Current value? I don't think... (like Application.Current is null in Design-time)

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Edit: why do not use design time datacontext? d:DataContext