Question

I notice that in online tutorials people use specific dp values for width and height of any view

For example, android:layout width =”20dp”
I was wondering since we have so many devices and densities would it be better to determine this value programmatically?
For example I want a specific image to occupy 20% of the screen width then I would get the screen width and multiply by 20% and set width accordingly

U know dp is supposed to make it equal size on any screen no matter what density is but this not the case for many devices and example is galaxy s2 and galaxy note

Can you please enlighten me of my ways are correct?

Answer 1

the better way to do it is to use linear layout in your xmls and set layout_weight in it children with the value you want. You can use weight_sum in the linear layout to set the max weight too.

e.g

linear weight_sum = 100 and a textview inside with layout_weight = 20. it means your textview has 20% of the value of the linear.

p.s: for horizontal orientarion, weight = width and width = 0dp

for vertical, weight = height and height = 0

I hope to help you ^^