Binding failed

[OrangeANDc]

Hello，my develop environment is framework4.72+ prism。
when i use prism‘s InitializeShell method to start my loginView，visual studio show the following errors，then after logined，mainview’s togglebutton cannot function properity。

but if i don‘t use InitializeShell method，displaye the mainview directly，This problem would not apperance。Do you konw how to handel？

[Keboo]

@OrangeANDc that looks like it is expecting your UI to also have a ToggleButton named MenuToggleButton. Does that element exist in your MainWindow?

[OrangeANDc]

that is strange when i change this way to bind then it works，

I find it in Microsoft official documents:
In WPF and XAML 2006, element references are addressed by the framework-level feature of ElementName binding. For most WPF applications and scenarios, ElementName binding should still be used. Exceptions to this general guidance might include cases where there are data context or other scoping considerations that make data binding impractical and where markup compilation is not involved.