Order Of Evaluation With Relative Layouts, Best Practices And Parsing Of Relative-layout

I read this ' It used to be that Android would use a single pass to process RelativeLayout-defined rules. That meant you could not reference a widget (e.g., via android:layout_abov

Solution 1:

@+id/name creates a new id, if it doesn't already exist. @id/name references an existing id, and will never create one.

I'm not sure if you can use @id/name before @+id/name in the same file. If not, I can think of two workarounds:

1. Always use @+id/name.

2. Define all id's in the ids.xml file, and always use @id/name.

Solution 2:

This is general information on how Android draw views. I think that Android passes twice through all the view, but it doesn't pass through each single view once. So if you have a reference from one xml to another it will always work fine, but if you have references inside a single xml you must be carefull to order the elements in the xml correctly. For example, I have view1 and view2 in my RelativeLayout. If I want to refer to view2 from view1 I must declare view2 before view1.