android资源类型

 

资源分组类型：

animator/	XML files that define property animations.
anim/	XML files that define tween animations. (Property animations can also be saved in this directory, but the animator/ directory is preferred for property animations to distinguish between the two types.)
color/	XML files that define a state list of colors. See Color State List Resource
drawable/	Bitmap files (.png, .9.png, .jpg, .gif) or XML files that are compiled into the following drawable resource subtypes: Bitmap files Nine-Patches (re-sizable bitmaps) State lists Shapes Animation drawables Other drawables See Drawable Resources.
layout/	XML files that define a user interface layout. See Layout Resource.
menu/	XML files that define application menus, such as an Options Menu, Context Menu, or Sub Menu. See Menu Resource.
raw/	Arbitrary files to save in their raw form. To open these resources with a raw InputStream, call Resources.openRawResource() with the resource ID, which is R.raw.filename. However, if you need access to original file names and file hierarchy, you might consider saving some resources in the assets/ directory (instead of res/raw/). Files in assets/ are not given a resource ID, so you can read them only using AssetManager.
values/	XML files that contain simple values, such as strings, integers, and colors. Whereas XML resource files in other res/ subdirectories define a single resource based on the XML filename, files in the values/ directory describe multiple resources. For a file in this directory, each child of the <resources> element defines a single resource. For example, a <string> element creates an R.string resource and a <color> element creates an R.color resource. Because each resource is defined with its own XML element, you can name the file whatever you want and place different resource types in one file. However, for clarity, you might want to place unique resource types in different files. For example, here are some filename conventions for resources you can create in this directory: arrays.xml for resource arrays (typed arrays). colors.xml for color values dimens.xml for dimension values. strings.xml for string values. styles.xml for styles. See String Resources, Style Resource, and More Resource Types.
xml/	Arbitrary XML files that can be read at runtime by calling Resources.getXML(). Various XML configuration files must be saved here, such as a searchable configuration.

注：不能在res目录下直接保存任何资源文件，否则会出现编译错误，不能通过编译
   

在以上的目录中，所有的资源为默认的资源信息，然而android设备多种多样，需要为不同的设备提供不同的资源以达到最佳的适配效果。

 

为不同设备配置最佳资源的规则：

1、  为不同的资源创建不同资源目录:res/<resources_name>-<config_qualifier>.

resources_name:资源的种类，同上目录结构中信息

config_qualifier:设备配置信息

2、不同资源目录下，资源名称要相同

res/
    drawable/   
        icon.png
        background.png    
    drawable-hdpi/  
        icon.png
        background.png  

         3、 目录配置config_qualifier参考表：

• 多个限定符可以用于一个文件，限定符之间用“-”隔开：drawable-en-rUS-land
• 限定符之间要严格按照顺序，顺序下表：

MCC and MNC	Examples: mcc310 mcc310-mnc004 mcc208-mnc00 etc.	The mobile country code (MCC), optionally followed by mobile network code (MNC) from the SIM card in the device. For example, mcc310 is U.S. on any carrier, mcc310-mnc004 is U.S. on Verizon, and mcc208-mnc00 is France on Orange. If the device uses a radio connection (GSM phone), the MCC and MNC values come from the SIM card. You can also use the MCC alone (for example, to include country-specific legal resources in your application). If you need to specify based on the language only, then use the language and region qualifier instead (discussed next). If you decide to use the MCC and MNC qualifier, you should do so with care and test that it works as expected. Also see the configuration fields mcc, and mnc, which indicate the current mobile country code and mobile network code, respectively.
Language and region	Examples: en fr en-rUS fr-rFR fr-rCA etc.	The language is defined by a two-letter ISO 639-1 language code, optionally followed by a two letter ISO 3166-1-alpha-2 region code (preceded by lowercase "r"). The codes are not case-sensitive; the r prefix is used to distinguish the region portion. You cannot specify a region alone. This can change during the life of your application if the user changes his or her language in the system settings. See Handling Runtime Changes for information about how this can affect your application during runtime. See Localization for a complete guide to localizing your application for other languages. Also see the locale configuration field, which indicates the current locale.
Layout Direction	ldrtl ldltr	The layout direction of your application. ldrtl means "layout-direction-right-to-left". ldltr means "layout-direction-left-to-right" and is the default implicit value. This can apply to any resource such as layouts, drawables, or values. For example, if you want to provide some specific layout for the Arabic language and some generic layout for any other "right-to-left" language (like Persian or Hebrew) then you would have: res/ layout/ main.xml (Default layout) layout-ar/ main.xml (Specific layout for Arabic) layout-ldrtl/ main.xml (Any "right-to-left" language, except for Arabic, because the "ar" language qualifier has a higher precedence.) Note: To enable right-to-left layout features for your app, you must set supportsRtl to "true" and set targetSdkVersion to 17 or higher. Added in API level 17.
smallestWidth	sw<N>dp Examples: sw320dp sw600dp sw720dp etc.	The fundamental size of a screen, as indicated by the shortest dimension of the available screen area. Specifically, the device's smallestWidth is the shortest of the screen's available height and width (you may also think of it as the "smallest possible width" for the screen). You can use this qualifier to ensure that, regardless of the screen's current orientation, your application has at least <N> dps of width available for its UI. For example, if your layout requires that its smallest dimension of screen area be at least 600 dp at all times, then you can use this qualifer to create the layout resources, res/layout-sw600dp/. The system will use these resources only when the smallest dimension of available screen is at least 600dp, regardless of whether the 600dp side is the user-perceived height or width. The smallestWidth is a fixed screen size characteristic of the device; the device's smallestWidth does not change when the screen's orientation changes. The smallestWidth of a device takes into account screen decorations and system UI. For example, if the device has some persistent UI elements on the screen that account for space along the axis of the smallestWidth, the system declares the smallestWidth to be smaller than the actual screen size, because those are screen pixels not available for your UI. Thus, the value you use should be the actual smallest dimension required by your layout (usually, this value is the "smallest width" that your layout supports, regardless of the screen's current orientation). Some values you might use here for common screen sizes: 320, for devices with screen configurations such as: 240x320 ldpi (QVGA handset) 320x480 mdpi (handset) 480x800 hdpi (high density handset) 480, for screens such as 480x800 mdpi (tablet/handset). 600, for screens such as 600x1024 mdpi (7" tablet). 720, for screens such as 720x1280 mdpi (10" tablet). When your application provides multiple resource directories with different values for the smallestWidth qualifier, the system uses the one closest to (without exceeding) the device's smallestWidth. Added in API level 13. Also see the android:requiresSmallestWidthDp attribute, which declares the minimum smallestWidth with which your application is compatible, and the smallestScreenWidthDp configuration field, which holds the device's smallestWidth value. For more information about designing for different screens and using this qualifier, see the Supporting Multiple Screens developer guide.
Available width	w<N>dp Examples: w720dp w1024dp etc.	Specifies a minimum available screen width, in dp units at which the resource should be used—defined by the <N> value. This configuration value will change when the orientation changes between landscape and portrait to match the current actual width. When your application provides multiple resource directories with different values for this configuration, the system uses the one closest to (without exceeding) the device's current screen width. The value here takes into account screen decorations, so if the device has some persistent UI elements on the left or right edge of the display, it uses a value for the width that is smaller than the real screen size, accounting for these UI elements and reducing the application's available space. Added in API level 13. Also see the screenWidthDp configuration field, which holds the current screen width. For more information about designing for different screens and using this qualifier, see the Supporting Multiple Screens developer guide.
Available height	h<N>dp Examples: h720dp h1024dp etc.	Specifies a minimum available screen height, in "dp" units at which the resource should be used—defined by the <N> value. This configuration value will change when the orientation changes between landscape and portrait to match the current actual height. When your application provides multiple resource directories with different values for this configuration, the system uses the one closest to (without exceeding) the device's current screen height. The value here takes into account screen decorations, so if the device has some persistent UI elements on the top or bottom edge of the display, it uses a value for the height that is smaller than the real screen size, accounting for these UI elements and reducing the application's available space. Screen decorations that are not fixed (such as a phone status bar that can be hidden when full screen) are not accounted for here, nor are window decorations like the title bar or action bar, so applications must be prepared to deal with a somewhat smaller space than they specify. Added in API level 13. Also see the screenHeightDp configuration field, which holds the current screen width. For more information about designing for different screens and using this qualifier, see the Supporting Multiple Screens developer guide.
Screen size	small normal large xlarge	small: Screens that are of similar size to a low-density QVGA screen. The minimum layout size for a small screen is approximately 320x426 dp units. Examples are QVGA low density and VGA high density. normal: Screens that are of similar size to a medium-density HVGA screen. The minimum layout size for a normal screen is approximately 320x470 dp units. Examples of such screens a WQVGA low density, HVGA medium density, WVGA high density. large: Screens that are of similar size to a medium-density VGA screen. The minimum layout size for a large screen is approximately 480x640 dp units. Examples are VGA and WVGA medium density screens. xlarge: Screens that are considerably larger than the traditional medium-density HVGA screen. The minimum layout size for an xlarge screen is approximately 720x960 dp units. In most cases, devices with extra large screens would be too large to carry in a pocket and would most likely be tablet-style devices. Added in API level 9. Note: Using a size qualifier does not imply that the resources are only for screens of that size. If you do not provide alternative resources with qualifiers that better match the current device configuration, the system may use whichever resources are the best match. Caution: If all your resources use a size qualifier that is larger than the current screen, the system will not use them and your application will crash at runtime (for example, if all layout resources are tagged with the xlarge qualifier, but the device is a normal-size screen). Added in API level 4. See Supporting Multiple Screens for more information. Also see the screenLayout configuration field, which indicates whether the screen is small, normal, or large.
Screen aspect	long notlong	long: Long screens, such as WQVGA, WVGA, FWVGA notlong: Not long screens, such as QVGA, HVGA, and VGA Added in API level 4. This is based purely on the aspect ratio of the screen (a "long" screen is wider). This is not related to the screen orientation. Also see the screenLayout configuration field, which indicates whether the screen is long.
Screen orientation	port land	port: Device is in portrait orientation (vertical) land: Device is in landscape orientation (horizontal) This can change during the life of your application if the user rotates the screen. See Handling Runtime Changes for information about how this affects your application during runtime. Also see the orientation configuration field, which indicates the current device orientation.
UI mode	car desk television appliance	car: Device is displaying in a car dock desk: Device is displaying in a desk dock television: Device is displaying on a television, providing a "ten foot" experience where its UI is on a large screen that the user is far away from, primarily oriented around DPAD or other non-pointer interaction appliance: Device is serving as an appliance, with no display Added in API level 8, television added in API 13. For information about how your app can respond when the device is inserted into or removed from a dock, read Determining and Monitoring the Docking State and Type. This can change during the life of your application if the user places the device in a dock. You can enable or disable some of these modes using UiModeManager. See Handling Runtime Changes for information about how this affects your application during runtime.
Night mode	night notnight	night: Night time notnight: Day time Added in API level 8. This can change during the life of your application if night mode is left in auto mode (default), in which case the mode changes based on the time of day. You can enable or disable this mode using UiModeManager. See Handling Runtime Changes for information about how this affects your application during runtime.
Screen pixel density (dpi)	ldpi mdpi hdpi xhdpi nodpi tvdpi	ldpi: Low-density screens; approximately 120dpi. mdpi: Medium-density (on traditional HVGA) screens; approximately 160dpi. hdpi: High-density screens; approximately 240dpi. xhdpi: Extra high-density screens; approximately 320dpi. Added in API Level 8 nodpi: This can be used for bitmap resources that you do not want to be scaled to match the device density. tvdpi: Screens somewhere between mdpi and hdpi; approximately 213dpi. This is not considered a "primary" density group. It is mostly intended for televisions and most apps shouldn't need it—providing mdpi and hdpi resources is sufficient for most apps and the system will scale them as appropriate. This qualifier was introduced with API level 13. There is a 3:4:6:8 scaling ratio between the four primary densities (ignoring the tvdpi density). So, a 9x9 bitmap in ldpi is 12x12 in mdpi, 18x18 in hdpi and 24x24 in xhdpi. If you decide that your image resources don't look good enough on a television or other certain devices and want to try tvdpi resources, the scaling factor is 1.33*mdpi. For example, a 100px x 100px image for mdpi screens should be 133px x 133px for tvdpi. Note: Using a density qualifier does not imply that the resources are only for screens of that density. If you do not provide alternative resources with qualifiers that better match the current device configuration, the system may use whichever resources are the best match. See Supporting Multiple Screens for more information about how to handle different screen densities and how Android might scale your bitmaps to fit the current density.
Touchscreen type	notouch finger	notouch: Device does not have a touchscreen. finger: Device has a touchscreen that is intended to be used through direction interaction of the user's finger. Also see the touchscreen configuration field, which indicates the type of touchscreen on the device.
Keyboard availability	keysexposed keyshidden keyssoft	keysexposed: Device has a keyboard available. If the device has a software keyboard enabled (which is likely), this may be used even when the hardware keyboard is not exposed to the user, even if the device has no hardware keyboard. If no software keyboard is provided or it's disabled, then this is only used when a hardware keyboard is exposed. keyshidden: Device has a hardware keyboard available but it is hidden and the device does not have a software keyboard enabled. keyssoft: Device has a software keyboard enabled, whether it's visible or not. If you provide keysexposed resources, but not keyssoft resources, the system uses the keysexposed resources regardless of whether a keyboard is visible, as long as the system has a software keyboard enabled. This can change during the life of your application if the user opens a hardware keyboard. See Handling Runtime Changes for information about how this affects your application during runtime. Also see the configuration fields hardKeyboardHidden and keyboardHidden, which indicate the visibility of a hardware keyboard and and the visibility of any kind of keyboard (including software), respectively.
Primary text input method	nokeys qwerty 12key	nokeys: Device has no hardware keys for text input. qwerty: Device has a hardware qwerty keyboard, whether it's visible to the user or not. 12key: Device has a hardware 12-key keyboard, whether it's visible to the user or not. Also see the keyboard configuration field, which indicates the primary text input method available.
Navigation key availability	navexposed navhidden	navexposed: Navigation keys are available to the user. navhidden: Navigation keys are not available (such as behind a closed lid). This can change during the life of your application if the user reveals the navigation keys. See Handling Runtime Changes for information about how this affects your application during runtime. Also see the navigationHidden configuration field, which indicates whether navigation keys are hidden.
Primary non-touch navigation method	nonav dpad trackball wheel	nonav: Device has no navigation facility other than using the touchscreen. dpad: Device has a directional-pad (d-pad) for navigation. trackball: Device has a trackball for navigation. wheel: Device has a directional wheel(s) for navigation (uncommon). Also see the navigation configuration field, which indicates the type of navigation method available.
Platform Version (API level)	Examples: v3 v4 v7 etc.	The API level supported by the device. For example, v1 for API level 1 (devices with Android 1.0 or higher) and v4 for API level 4 (devices with Android 1.6 or higher). See the Android API levels document for more information about these values.

 

•  限定符之间不能嵌套：res/drawable/drawable-en/ iswrong
• 不区分大小写，有资源编译器统一将目录名称编译成小写.
• 每一个文件只能有一个同类的限定修饰符：drawable-rES-rFR/. is wrong   instead of drawable-rES/ and drawable-rFR/

别名：

     应用场景：有一个资源，你有不想当做默认的资源使用，需要在不同的资源目中使用，当然你可以将该资源copy到每一个对应的文件夹，然而这是一个非常麻烦的事情，一旦该资源的内容发生变化，那么你不得不去更改每一个目录下的信息。当然你也可以采用别名的方式去处理，你可以在默认的资源文件夹下面为该资源创建别名。

     不是所有的资源都可以采用别名的方式去处理，animation, menu, raw, and other都可以采用别名，除了在xml/目录下的资源不能采用别名。

      假设drawable-en和drawable-us都有一个drawable icon.png 那么你可以在drawable目录下放置drawable icon.png，分别在drawable-en和drawable-us下创建一个icon.xml 分别指向drawable下的icon.png

<?xml version="1.0" encoding="utf-8"?><bitmapxmlns:android="http://schemas.android.com/apk/res/android"
    android:src="@drawable/icon"/>

 layout:

<?xml version="1.0" encoding="utf-8"?><merge>
    <includelayout="@layout/main_ltr"/></merge>

 values:

<?xml version="1.0" encoding="utf-8"?><resources>
    <stringname="hello">Hello</string>
    <stringname="hi">@string/hello</string></resources>

 colors:

<?xml version="1.0" encoding="utf-8"?><resources>
    <colorname="yellow">#f00</color>
    <colorname="highlight">@color/red</color></resources>

 最佳适配方式：

     如果你的应用要支持不同设备，不同分辨率，那么提供默认的资源就非常重要。

     假设你的应用支持多种语言，而且你将所有的语言描述都写在带有限定符的文件家中如：values-en，且没有提供默认的语言支持，那么一旦你的应用程序运行在中文的设备上，程序将会崩溃，最好的解决办法是提供默认的语言支持，即使用户不了解里面的内容，也比程序直接崩溃的好，上述就解决方案是：写一套语言描述的string.xml 放在没有修饰符的values中，当然string.xml中的内容你可以是中文的内容，也可以是法文。

    同样的，如果你的应用支持横竖屏的话，你需要用横屏或者竖屏中的一个来做默认，假设横屏layout-land，竖屏layout-port，默认使用横屏的话，那么将横屏的文件夹更名为layout。

    提供默认的资源非常重要不仅是因为有些设备的配置超出你的预料之中，而且android系统在新版本中的特性在某些老版本中是不支持。如果的你应用程序采用新版的sdk编写，而运行在老版本的设备上，一旦没有提供默认的支持，程序有可能会崩溃，因为程序需要新版的特性。假设你的应用程序中使用了“night mode（night/not night）”这个特性在API level 8 中添加，而该应用程序运行在API level 4的设备上，那么程序将不能访问诸如drawable-night之类文件夹下的资源，最好的办法是提供默认的支持drawable。

 

访问目录资源规则

android访问某个资源如何定位到某个文件夹是根据你运行程序设备的配置而言。假设有如下文件夹：

 

drawable/
drawable-en/
drawable-fr-rCA/
drawable-en-port/
drawable-en-notouch-12key/
drawable-port-ldpi/
drawable-port-notouch-12key/

 同样假设当前设备的配置如下：

Locale = en-GB 
Screen orientation = port 
Screen pixel density = hdpi
Touchscreen type = notouch 
Primary text input method = 12key

   那么应用程序如何找到最佳的适配目录drawable-en-port/，有一下几个规则：

• 剔除与设备配置相矛盾的文件夹，(screen size density 不参与排除)
• 选择最高优先匹配的限定符表2,由MCC逐步向下匹配
• 如果没有找到包含有限匹配的目录则执行上一步，有则执行下一步
• 排除不包含制定限制符的文件夹。
• 重复前面3个步骤，直到所剩余的文件夹为1个。

1、排除同设备配置矛盾的文件夹：
drawable/
drawable-en/
drawable-fr-rCA/
drawable-en-port/
drawable-en-notouch-12key/
drawable-port-ldpi/
drawable-port-notouch-12key/

2、MCC，MNC木有，根据language排除：
drawable/ 
drawable-en/
drawable-fr-rCA/
drawable-en-port/
drawable-en-notouch-12key/
drawable-port-ldpi/
drawable-port-notouch-12key/

3、根据屏幕方向排除：
drawable/ 
drawable-en/
drawable-fr-rCA/
drawable-en-port/
drawable-en-notouch-12key/
drawable-port-ldpi/
drawable-port-notouch-12key/