android:layout_marginLeft android:paddingLeft android:layout_gravity android:gravity

相信你一看就懂：<__>

android:layout_marginLeft

Specifies extra space on the left side of this view. This space is outside this view's bounds.  指的是控件本View 相对于外部控件的一个偏移量。

android:paddingLeft

Sets the padding, in pixels, of the left edge; see padding. 指控件内部内容相对于所在控件边距的的偏移量。

下同：

android:layout_gravity

Standard gravity constant that a child supplies to its parent. Defines how the child view should be positioned, on both the X and Y axes, within its enclosing layout.

android:gravity

Specifies how an object should position its content, on both the X and Y axes, within its own bounds.