PercentRelativeLayout is more Performant?

问题:

I always use LinearLayout and RelativeLayouts, and i was reading about the "new" PercentRelativeLayout. I have a few questions:

• Should i always start using this one or only in cases of nested weights with linearlayout?

• Is this more performant than the others?

Any other information about PercentRelativeLayout it will be welcome.

Thanks!

回答1:

Looking at the source code, a PercentRelativeLayout is basically a minor extension of a RelativeLayout. This means you need to make the same considerations as when you choose between a RelativeLayout and LinearLayout.

• RelativeLayout needs 2 measure passes -> avoid using it as the root of a deep view hierarchy or nesting multiple RelativeLayouts (more info in this stackoverflow post)
• Layout weights in LinearLayout also require 2 measure passes -> try to replace these constructs as much as possible with one Relative/GridLayout (more info in this stackoverflow post)

Finally it is worth noting that:

• Don't optimise unless you have a problem
• Try to keep your hierarchies as flat as possible

回答2:

PercentRelativeLayout 

is just a extension of RelativeLayout so i think:

1) u should use it in case of nested weights with linearlayout as they are bad for performance

2)No,but depends on your useCase. For ex:-it has less performance than LinearLayout and RelativeLayout but more than LinearLayout with nested weight

Also u can refer this post from android developer: http://developer.android.com/training/improving-layouts/optimizing-layout.html

回答3:

Try PercentRelativeLayout and PercentFrameLayout of Percent Support Library

http://android-er.blogspot.in/2015/08/try-percentrelativelayout-and.html

here you can find best comparison for both layouts.