Common Properties of relativelayout relative Layout

Class 1: the property value is true or false.
Android: layout_centerhrizontal horizontal center
Android: layout_centervertical vertical center
Android: layout_centerinparent is completely centered over the parent Element
Android: layout_alignparentbottom: attach the lower edge of the parent Element
Android: layout_alignparentleft: Stick the left edge of the parent Element
Android: layout_alignparentright: attaches the right edge of the parent element.
Android: layout_alignparenttop: top the parent Element
Android: layout_alignwithparentifmissing

Class 2: the property value must be the reference name "@ ID/ID-name" of the ID"
Android: layout_below is under an element
Android: layout_abve is above an element.
Android: layout_toleftof on the left of an element
Android: layout_torightof on the right of an element

Android: layout_aligntop: Align the top edge of an element with the top edge of an element.
Android: layout_alignleft: Align the left edge of an element with the left edge of an element.
Android: layout_alignbottom: the bottom edge of the current element is aligned with the bottom edge of an element.
Android: layout_alignright: the right edge of an element is aligned with the right edge of an element.

Category 3: Move pixels

Android: layout_margintop offset value;

Android: layout_marginbottom offset value;

Android: layout_marginleft value of the left offset;

Android: value of the right offset of layout_marginright;