Introduction and use of Android resource files

Introduction and use of Android resource files

1. Resource introduction:
Defined in the res Directory: strings, colors, arrays, menus, images, videos, etc.; use these resources in applications;

2. advantages of using resources: reduces the amount of code and facilitates later maintenance;

3. Resource types:
Directory resource type description
Res/anim xml animation information, frame animation or this complementary Animation
Res/layout xml save layout information
Res/values xml string, color, size, type, and topic. The file can be named in the form of key-value. We recommend that different files store different types of values;
Res/menu xml saves menu resources. A resource file represents a menu
Res/xml is used to save any xml file, which can be read by code Resources. getXML;

Resources in the res/raw directory of any type are not compiled. You can call Resource. openRawResource (int id) to obtain the binary input stream of the Resource;
Assets of any type are the same as raw and will not be compiled. The difference is that the resource source files in this directory will not generate resource IDs;
Res/drawable graphics save images in multiple formats


4. system resources:
Android contains a large number of system resources, which are stored in the/platforms/android-version/data/res directory of the SDK;
Use: andorid. R. Resource file type. Resource ID in the code, reference in the XML file: @ android: Resource Type/resource ID;

5. How to use custom resources:
For example, how to use color resources ....
Resource location res/values/colors. xml
Color XML file format
Root element
Child element: # Color_value
Resource. getColor ();
Format of referenced Resource: in java: R. color. color_name
In xml: @ [package:] color/color_name

6. Use string resources:

Resource location: res/vaules/strings. xml
String xml file format
Root element
String_value
Method for obtaining string Resources. getString ();

Reference string in java: R. string. string_name = key
In xml: @ string/string_name

7. Use size resources:

Resource location: res/vaules/dimens. xml
String xml file format
Root element
Dimen_value

GetResources (). getDimension ()

Reference string in java: R. dimen. dimen_name = key
In xml: @ dimen/dimen_name


8. Use drawables resources:
A drawable resource is an image or color resource used to draw a screen. It is obtained through Resourcs. getDrawable (): method;
Drawable resources are classified into three types: BitmapFile (bitmap file), Color Drawable (Color), and Nine-Patch Image (Nine images );
Supported bitmap files for android include: png, jpg, and gif.

The usage is the same as above;