If you are new to android development world, you may have doubts about the word “layout”.
So let’s start here,
In Android, layout describes the appearance of the app. Layouts are just resourced files. The instructions or content in layout decides to position your widget and make your user interface.
The layout contains view, viewgroup objects and <merge> tag. Just like HTML, It must have a root element. It can contain more GUI widgets like Button, TextView etc. Nested elements are also supported.
An app can have more than one screens based on developer needs. So you can have many layouts as you want.
Layout resource names must contain only lowercase a-z, 0-9, or underscore otherwise, you might end with an error.
How to create layout in android?
- Using XML
You can use XML straightforward vocabulary to specify your UI. For beginners, you can check it out drag and drop feature. It helps us to drag a view which you want and drop it wherever you want in layout design. The XML code will automatically complete by android studio.
For localization (translating strings into different languages), XML layout would be a better idea.
Note: You must put xmlns:android attribute with android namespace inside root element.
For an example: assume LinearLayout as your root element.
- Programmatically at runtime
It’s not generally recommended. There may be occasions to make your layout at runtime. But it mixes up UI code and code that controlling app behavior. So it may become difficult to tweak and refine user interface.
Where is layout files located at?
Android studio automatically creates a directory to hold your layout files – layout subdirectory.
In your project structure
all resource files stored in res (resources folder).
How to create a layout file in android studio?
Right Click on your default layout subdirectory
New -> Layout resource file -> Enter layout Name and click OK.
Also give details of the root element, source set, Directory name and other available qualifiers.
How to rename layout file in android studio?
Right click on your layout file which want to rename
Refactor -> Rename -> give new file name -> Refactor. You can use shift + F6 key also.