Best method for async initialization of view model in MVVM pattern (WPF)

Question

I'm working on a business application (C#, WPF, EF, MVVM). I need to load a bunch of items from database, create view models for them and put them in a window. Is there a way to create the view model in another thread or do something similar to speed up UI?

1. The approximate average time needed to fetch all items from database = 1s
2. The approximate average time needed to instantiate all view models = 3s

I'm doing the first part through Loaded event of each item. but the second part is the bottleneck. any insight would be appreciated.

• Dtex: Creating view models in a background thread is generally a bad idea since they need to be bound on controls created on the main thread. I would try to reduce the initialization time first.
• Robert Harvey: Or employ some layered caching.
• Bizhan: @Dtex: Thanks, I can remove some unnecessary graphics.
• Bizhan: @Robert: can you explain how layer caching can be done?
• Robert Harvey: msdn.microsoft.com/en-us/library/dd997362(v=vs.110).aspx

Answer 1

Break up the views into separate tabs/fly-outs etc and only populate these bits when the tabs/fly-outs are actually switched to.

Further to the above only populate the first element i.e. SELECT 1 only then populate the rest in the view on a scroll or drop down operation etc..

Lazy Loading.

In other words this is some of the layered caching alluded too and i do not see why the ViewModel has to have the data in advance as long as it goes off and gets it whenever requested..