What is android:weightSum in android, and how does it work?

Question

I want to know: What is android:weightSum and layout weight, and how do they work?

Answer 1

Per documentation, android:weightSum defines the maximum weight sum, and is calculated as the sum of the layout_weight of all the children if not specified explicitly.

Let's consider an example with a LinearLayout with horizontal orientation and 3 ImageViews inside it. Now we want these ImageViews always to take equal space. To acheive this, you can set the layout_weight of each ImageView to 1 and the weightSum will be calculated to be equal to 3 as shown in the comment.

    android:orientation="horizontal"
    android:layout_gravity="center">

   
  .....

weightSum is useful for having the layout rendered correctly for any device, which will not happen if you set width and height directly.