Android Reading notes 1

Layer four
Linux kernel layer
Library Java Virtual Machine
Framework
Application

Four components
activity (activity), Service (services), broadcast receiver ( Broadcast receiver), content provider

Device drop-down point DDMS the right drop-down list of reset adb is available

Some notes about the project directory
src     java Code Storage Place
gen     This directory is automatically generated, never modify them
asserts     Some of the files packaged with the program are placed here, and if you use the Web, the relevant pages will also be stored here
bin    apk and some of the compile-time directories here
libs     The third-party jar package
res     projects used in the picture, layout (XML layout), string (values) are placed here
androidmanifest.xml   The four components defined in the   program are registered in this file, you can also add permission declarations to the application, or you can reassign the minimum and target versions specified when the project was created
project.properties     Specifies the SDK version to use when compiling the program

Resource is placed in the Res directory under the beginning of the
Drawable directory is to put pictures, different resolutions of the picture used on the machine, if only one picture is placed inside the-hdpi
layout, Values are XML files that reference these resources in Java or XML, use R.STRING.XXXX when referenced in Java, use @string/xxxx when referencing in other XML, and XXXX is the XML key value. String is a reference to the strings, if the reference is a picture is drawable, if you are referring to a layout file is layouts
Note: If you reference an ID in XML, you want to use @id/id_name; If you define an ID in XML, you use @+id /id_name

Android Reading note 1