Android LinearLayout Why Gravity don't work

Some Android Developer may not be know well of linearlayout. This is the know sth about the gravity of its chilren;

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1) wahts The diffrence between "Gravity" Android "Layout_gravity"?

Gravity:is STH to itself;   This is the want its content to layout; its see a TextView; Provided its WD is 200;   and its content (text) measured WD is 150; This Gravity setting would make it text align Left? Top? Center? etc...

Layout_gravity:is STH to its parent; This tells It;s the parent how it wants is layed out; Again this TextView with its parent linearlayout; Provided parent WD is, HT is 400;

2) Why Does my layout_gravity?

Layout_gravity is STH relevent to its parent orentation;

If its orentation is horizontal, top, BTM, center_vertical'll be effective;

else if is vertical:left, right, center_horizontal is effective;

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That's for TODAY! MY POOR UBUNTU INPUT METHOD!!!

Android LinearLayout Why Gravity don't work