Bad performance when use RecyclerView inside NestedScrollView

Question

I'm developing a search contact feature, in that screen, there is a RecyclerView inside NestedScrolView (fillViewport = true). Screen design: (This design is accepted by customer, I can't change it)

After loading all contacts of current device into an ArrayList, the search results are filtered from this array.
There is several cases that make the app very laggy:
1. When user type an input that have no result, then user clear search, I have to show all results again. The NestedScrollView has to render UI for all items of RecyclerView (for example: 300 items).
2. When the quantity of results has many changes (for example, from 1 to 300 items). The NestedScrollView has to render UI for a lot of items of RecyclerView

I know this design breaks recycling technique of RecyclerView, but I can't change it.
What I tried:

?

In AndroidManifest:

recyclerView.setNestedScrollingEnabled(false);

The adapter:

android:windowSoftInputMode="adjustNothing"

Answer 1

您正在使用RecyclerView错误。而不是将您的RecyclerView放在NestedScrollView中，而是将您的＆＃34; Header＆＃34;和＆＃34;搜索框＆＃34;在RecyclerView内部作为不同的视图类型。

这个answer就是一个很好的例子。