Using the Assembly Tree - icsharpcode/ilspy-vscode GitHub Wiki

After successful start you will see new "ILSpy" commands in VS Code's Command Palette (Ctrl+Shift+P):

You can either select an assembly file present in your workspace or choose any assembly file on your system. After selection the assembly will be shown in a new Explorer view "ILSpy: Assemblies":

The tree view allows to explore the namespaces, members and types of the assembly. Click on an item will decompile the member on-demand and show its C# or IL code in an editor view.

Auto-loaded Dependencies in Assembly Tree

When viewing assemblies and their types and members, the extension might need to load additional assemblies to properly resolve types from dependencies. This usually happens in the background, but if the "Auto-load Dependencies" setting is active (default), those additional dependencies are also shown in assembly tree with blue color:

This behavior is similar to ILSpy desktop application.