在main.xml 或者其他xml 布局文件中布局Button的时候,选择Android:gravity="center_horizontal",意思是Place object in the horizontal center of its container, not changing its size.我们用RelativeLayout 布局,这样可以使不同的组件有对齐的方式。
[代码] main.xml
01 | <? xml version = "1.0" encoding = "utf-8" ?> |
02 | < RelativeLayout xmlns:Android = "http://schemas.android.com/apk/res/android" |
03 | Android:layout_width = "fill_parent" |
04 | Android:layout_height = "fill_parent" > |
05 | < TextView Android:id = "@+id/gallerytext" |
06 | Android:layout_width = "fill_parent" |
07 | Android:layout_height = "wrap_content" > |
09 | < Gallery Android:id = "@+id/gallery" |
10 | Android:layout_width = "fill_parent" |
11 | Android:layout_height = "wrap_content" > |
13 | < Button Android:id = "@+id/btngal" |
14 | Android:layout_width = "wrap_content" |
15 | Android:layout_height = "wrap_content" |
16 | Android:gravity = "center_horizontal" |
17 | Android:textSize = "20sp" |
18 | Android:layout_alignParentBottom = "true" |
19 | Android:layout_centerHorizontal = "true" |
20 | Android:text = "返回主界面" /> |
[代码] 简单说明
1 | 可以看到Button 与Gallery的对齐方式是居中对齐,也即Button 与Parent居中对齐。 |
3 | Android:gravity="CENTER_VERTICAL“:这个是垂直居中对齐 |
4 | Android:gravity="BOTTOM”:放在容器的底部 |
5 | Android:gravity="CENTER“ :放在容器的中心 |