Gravity 與 Visiable

今天在查看Astrid源碼的時候發現了界面佈局中Gravity和Visible的新用法，簡要記錄一下。

Gravity: API 文檔記錄

int	CENTER	Place the object in the center of its container in both the vertical and horizontal axis, not changing its size.
int	CENTER_HORIZONTAL	Place object in the horizontal center of its container, not changing its size.
int	CENTER_VERTICAL	Place object in the vertical center of its container, not changing its size.

 

android:visibility：API文檔記錄

這個頗有意思。

 

Constant	Value	Description
visible	0	Visible on screen; the default value.
invisible	1	Not displayed, but taken into account during layout (space is left for it).
gone	2	Completely hidden, as if the view had not been added.

 

注意invisible與gone的區別。

下面用圖演示一下：

注意看下面的稍後：

1：visible

2：invisible

 

「稍後」那個地方空白了

3：gone

這樣是否是清楚一點：

visible	invisible	gone