Android-the first Android program, android-android

Android-the first Android program, android-android

• Directory structure and functions of Android Projects

Directory	Function
Gen	Do not modify automatically generated files
Assets	Resources needed for custom projects, which cannot be identified by the Android platform
Res	Engineering resources, which can be identified by the Android platform and will be automatically generated in the gen directory
Drawable	Resources (images) that can be drawn correspond to different resolutions
Layout	Layout management File
Values	Manage constant values
AndroidManifest. xml	The project list file describes the entire Android application.

• Activity

Activity is the user interface of the android application. Multiple controls can be placed in an Activity.

Activity can also be understood as the control container.

• Important attributes

Android: layout_width

Android: layout_height

Fill_parent | wrap_content

Android: layout_weight weight (0 by default)

Android: Unique id used for reference in a program or configuration file

Width and height are attributes that must be included in the control.