FAQ_19 如何判断 android 版本

android 已经发布很多版本，记住每个版本及其对应的版本名称，实在是没那个必要。

先看一张来自 http://zh.wikipedia.org/wiki/Android 的图：

但是，有些时候需要知道这些信息。所以，你需要知道到那里去找。

有问题，找源码！

下面是 android4.0//frameworks/base/core/java/android/os/Build.java 部分源码：

 /**     * Enumeration of the currently known SDK version codes.  These are the     * values that can be found in {@link VERSION#SDK}.  Version numbers     * increment monotonically with each official platform release.     */    public static class VERSION_CODES {        /**         * Magic version number for a current development build, which has         * not yet turned into an official release.         */        public static final int CUR_DEVELOPMENT = 10000;                /**         * October 2008: The original, first, version of Android.  Yay!         */        public static final int BASE = 1;                /**         * February 2009: First Android update, officially called 1.1.         */        public static final int BASE_1_1 = 2;                /**         * May 2009: Android 1.5.         */        public static final int CUPCAKE = 3;                /**         * September 2009: Android 1.6.         *          * <p>Applications targeting this or a later release will get these         * new changes in behavior:</p>         * <ul>         * <li> They must explicitly request the         * {@link android.Manifest.permission#WRITE_EXTERNAL_STORAGE} permission to be         * able to modify the contents of the SD card.  (Apps targeting         * earlier versions will always request the permission.)         * <li> They must explicitly request the         * {@link android.Manifest.permission#READ_PHONE_STATE} permission to be         * able to be able to retrieve phone state info.  (Apps targeting         * earlier versions will always request the permission.)         * <li> They are assumed to support different screen densities and         * sizes.  (Apps targeting earlier versions are assumed to only support         * medium density normal size screens unless otherwise indicated).         * They can still explicitly specify screen support either way with the         * supports-screens manifest tag.         * </ul>         */        public static final int DONUT = 4;                /**         * November 2009: Android 2.0         *          * <p>Applications targeting this or a later release will get these         * new changes in behavior:</p>         * <ul>         * <li> The {@link android.app.Service#onStartCommand         * Service.onStartCommand} function will return the new         * {@link android.app.Service#START_STICKY} behavior instead of the         * old compatibility {@link android.app.Service#START_STICKY_COMPATIBILITY}.         * <li> The {@link android.app.Activity} class will now execute back         * key presses on the key up instead of key down, to be able to detect         * canceled presses from virtual keys.         * <li> The {@link android.widget.TabWidget} class will use a new color scheme         * for tabs. In the new scheme, the foreground tab has a medium gray background         * the background tabs have a dark gray background.         * </ul>         */        public static final int ECLAIR = 5;                /**         * December 2009: Android 2.0.1         */        public static final int ECLAIR_0_1 = 6;                /**         * January 2010: Android 2.1         */        public static final int ECLAIR_MR1 = 7;                /**         * June 2010: Android 2.2         */        public static final int FROYO = 8;                /**         * November 2010: Android 2.3         */        public static final int GINGERBREAD = 9;                /**         * February 2011: Android 2.3.3.         */        public static final int GINGERBREAD_MR1 = 10;        /**         * February 2011: Android 3.0.         *         * <p>Applications targeting this or a later release will get these         * new changes in behavior:</p>         * <ul>         * <li> The default theme for applications is now dark holographic:         *      {@link android.R.style#Theme_Holo}.         * <li> The activity lifecycle has changed slightly as per         * {@link android.app.Activity}.         * <li> When an application requires a permission to access one of         * its components (activity, receiver, service, provider), this         * permission is no longer enforced when the application wants to         * access its own component.  This means it can require a permission         * on a component that it does not itself hold and still access that         * component.         * </ul>         */        public static final int HONEYCOMB = 11;                /**         * May 2011: Android 3.1.         */        public static final int HONEYCOMB_MR1 = 12;                /**         * June 2011: Android 3.2.         *         * <p>Update to Honeycomb MR1 to support 7 inch tablets, improve         * screen compatibility mode, etc.</p>         *         * <p>As of this version, applications that don't say whether they         * support XLARGE screens will be assumed to do so only if they target         * {@link #HONEYCOMB} or later; it had been {@link #GINGERBREAD} or         * later.  Applications that don't support a screen size at least as         * large as the current screen will provide the user with a UI to         * switch them in to screen size compatibility mode.</p>         *         * <p>This version introduces new screen size resource qualifiers         * based on the screen size in dp: see         * {@link android.content.res.Configuration#screenWidthDp},         * {@link android.content.res.Configuration#screenHeightDp}, and         * {@link android.content.res.Configuration#smallestScreenWidthDp}.         * Supplying these in <supports-screens> as per         * {@link android.content.pm.ApplicationInfo#requiresSmallestWidthDp},         * {@link android.content.pm.ApplicationInfo#compatibleWidthLimitDp}, and         * {@link android.content.pm.ApplicationInfo#largestWidthLimitDp} is         * preferred over the older screen size buckets and for older devices         * the appropriate buckets will be inferred from them.</p>         *         * <p>New {@link android.content.pm.PackageManager#FEATURE_SCREEN_PORTRAIT}         * and {@link android.content.pm.PackageManager#FEATURE_SCREEN_LANDSCAPE}         * features are introduced in this release.  Applications that target         * previous platform versions are assumed to require both portrait and         * landscape support in the device; when targeting Honeycomb MR1 or         * greater the application is responsible for specifying any specific         * orientation it requires.</p>         */        public static final int HONEYCOMB_MR2 = 13;        /**         * Android 4.0.         *         * <p>Applications targeting this or a later release will get these         * new changes in behavior:</p>         * <ul>         * <li> For devices without a dedicated menu key, the software compatibility         * menu key will not be shown even on phones.  By targeting Ice Cream Sandwich         * or later, your UI must always have its own menu UI affordance if needed,         * on both tablets and phones.  The ActionBar will take care of this for you.         * <li> 2d drawing hardware acceleration is now turned on by default.         * You can use         * {@link android.R.attr#hardwareAccelerated android:hardwareAccelerated}         * to turn it off if needed, although this is strongly discouraged since         * it will result in poor performance on larger screen devices.         * <li> The default theme for applications is now the "device default" theme:         *      {@link android.R.style#Theme_DeviceDefault}. This may be the         *      holo dark theme or a different dark theme defined by the specific device.         *      The {@link android.R.style#Theme_Holo} family must not be modified         *      for a device to be considered compatible. Applications that explicitly         *      request a theme from the Holo family will be guaranteed that these themes         *      will not change character within the same platform version. Applications         *      that wish to blend in with the device should use a theme from the         *      {@link android.R.style#Theme_DeviceDefault} family.         * <li> Managed cursors can now throw an exception if you directly close         * the cursor yourself without stopping the management of it; previously failures         * would be silently ignored.         * <li> The fadingEdge attribute on views will be ignored (fading edges is no         * longer a standard part of the UI).  A new requiresFadingEdge attribute allows         * applications to still force fading edges on for special cases.         * </ul>         */        public static final int ICE_CREAM_SANDWICH = 14;    }

ok，里面详细说明了版本号以及版本名称！

但是如何判断当前设备的 android 版本？

if (Build.VERSION.SDK_INT > 13) {// 4.0version    //}

这样可以在代码里面根据 android 设备的不同版本，做相应的处理。