Is there any difference between “center_horizontal|center_vertical” and “center”

问题

I want to center an image in a linearLayout.

Is there any difference between

android:gravity="center_horizontal|center_vertical"

and

android:gravity="center"

?

回答1:

No, there is no difference. According to source code

public static final int CENTER = CENTER_VERTICAL|CENTER_HORIZONTAL;

回答2:

There really is not difference between the two except that it's less code using center. combining center_horizontal and center_veritcal is the equivalent of center

回答3:

I know this is old question but i want just want to share to anyone what i found. And pardon the bad english.

Imagine Horizontal line as X an vertical line as Y (like the one used in 3d modeling model ex: maya and 3dmax).

_{(source: helpingwithmath.com)}

center_horizontal = this one will put your view/layout postion of X into zero

center_vertical = as you guess, it will make the postion Y into zero

center = this one will make the position X and Y into Zero

I figured this out by my own when trying all of them on my layout. Cant give an example because my printscreen isnt working.

I dont know if there is a documentation that tell you about this, so correct me if im wrong. I just hope it will help someone understand :cheers.

来源：https://stackoverflow.com/questions/17892786/is-there-any-difference-between-center-horizontalcenter-vertical-and-center