The error message returned when setting wrap_content in RelativeLayout is invalid,

The error message returned when setting wrap_content in RelativeLayout is invalid,

Respect labor results, reprinted please indicate the source: http://www.cnblogs.com/tangZH/p/8419053.html

 

During the project, I encountered a strange phenomenon. I set the width of RelativeLayout to wrap_content, and the components in RelativeLayout also set a fixed size, however, the RelativeLayout width is still full throughout the screen.

 

Why ??? Face-to-face

Baidu later found that the official documentation has explained:

A Layout where the positions of the children can be described in relation to each other or to the parent.Note that you cannot have a circular dependency between the size of the RelativeLayout and the position of its children. for example, you cannot have a RelativeLayout whose height is set to WRAP_CONTENT and a child set to ALIGN_PARENT_BOTTOM.

 

It means:Circular dependency cannot exist between the RelativeLayout size and the sub-level location. For example, you cannot set the RelativeLayout height to WRAP_CONTENT, and set the child to ALIGN_PARENT_BOTTOM.

 

The two situations I have encountered are as follows:

1. Set the RelativeLayout width to wrap_content, and the child component

Android: layout_alignParentEnd = "true"

As a result, the screen is filled with RelativeLayout width.

 

2. Set the height of RelativeLayout to wrap_content, and the child component

ALIGN_PARENT_BOTTOM

As a result, the screen is filled with RelativeLayout height.

 

Finally, I changed my mind to LinearLayout layout.