No orientation specified, and the default is horizontal.

整的错误提示信息为：No orientation specified, and the default is horizontal. This is a common source of bugs when

 children are added dynamically.

Wrong orientation? No orientation specified, and the default is horizontal, yet this layout 

 has multiple children where at least one has layout_width="match_parent"

通常发生这个错误提示的原因是我们直接在原有的页面上把别的布局标签改成<LinearLayout>，但是使用<LinearLayout>标签要指明方向，水平方向还是垂直方向

horizontal or vertical

所以直接修改，会导致没有指名线性布局的方向，只要添加上

 android:orientation = "vertical"

或

 android:orientation = "horizontal"

即可解决

from:http://blog.youkuaiyun.com/sky_monkey/article/details/21466975