如何获得Android系统版本

项目移植中，遇到需要区分不同系统版本的问题。于是查找相关方法如下：

android.os.Build类提供了当前系统信息。
可用if (Build.VERSION.SDK_INT < Build.VERSION_CODES.GINGERBREAD)这样来判断。

有人用这样一个函数来获取版本号：

public static int getAndroidSDKVersion() {
int version;
try {
version = Integer.valueOf(android.os.Build.VERSION.SDK);
} catch (NumberFormatException e) {
Log.e(e.toString());
}
return version;
}

android.os.Build.VERSION_CODES 值有如下，其中第二列的值就是API LEVEL编号：

int 1 (0x00000001)BASEOctober 2008: The original, first, version of Android.int 2 (0x00000001)BASE_1_1February 2009: First Android update, officially called 1.1.int 3 (0x00000001)CUPCAKEMay 2009: Android 1.5.int 10000 (0x00002710)CUR_DEVELOPMENTMagic version number for a current development build, which has not yet turned into an official release.int 5 (0x00000001)DONUTSeptember 2009: Android 1.6.int　ECLAIRNovember 2009: Android 2.0　Applications targeting this or a later release will get these new changes in behavior: 5 (0x00000008)The Service.onStartCommand function will return the new START_STICKY behavior instead of the old compatibility START_STICKY_COMPATIBILITY.int 6 (0x00000008)ECLAIR_0_1December 2009: Android 2.0.1int 7 (0x00000008)ECLAIR_MR1January 2010: Android 2.1int 8 (0x00000008)FROYOJune 2010: Android 2.2int GINGERBREADNovember 2010: Android 2.3　Applications targeting this or a later release will get these new changes in behavior: 9 (0x00000009)The application's notification icons will be shown on the new dark status bar background, so must be visible in this situation.int 10 (0x0000000a)GINGERBREAD_MR1February 2011: Android 2.3.3.int 11 (0x0000000b)HONEYCOMBFebruary 2011: Android 3.0.int 12 (0x0000000c)HONEYCOMB_MR1May 2011: Android 3.1.int 13 (0x0000000d)HONEYCOMB_MR2June 2011: Android 3.2.int 14 (0x0000000e)ICE_CREAM_SANDWICHOctober 2011: Android 4.0.int 15 (0x0000000f)ICE_CREAM_SANDWICH_MR1December 2011: Android 4.0.3.int 16 (0x00000010)