时间：2021-12-24 11:07:18 | 栏目：Android代码 | 点击：次
Android中由于不同版本API会有一些变化，导致一些较早版本可能不支持新的方法，或者某些功能处理过程不太一样，需要判断当前版本然后进行适当的处理。
那么，如何判断当前API的版本号呢？
例如判断api版本号是否大于等于19：
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {...}
其中，Build.VERSION_CODES.KITKAT = 19
Build.VERSION.SDK_INT是什么：
public static final int SDK_INT = SystemProperties.getInt("ro.build.version.sdk", 0);
获取系统属性配置文件中“ro.build.version.sdk”的值，该值即为当前设备的系统版本号。
在Android源码 frameworks\base\core\java\android\os\Build.java 文件中的 Build.VERSION_CODES 类下包含对应各个版本的版本号信息。
以下是Android 7.0版本下的源码：
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.
*/
public static final int DONUT = 4;
/**
* November 2009: Android 2.0
*/
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.
*/
public static final int HONEYCOMB = 11;
/**
* May 2011: Android 3.1.
*/
public static final int HONEYCOMB_MR1 = 12;
/**
* June 2011: Android 3.2.
*/
public static final int HONEYCOMB_MR2 = 13;
/**
* October 2011: Android 4.0.
*/
public static final int ICE_CREAM_SANDWICH = 14;
/**
* December 2011: Android 4.0.3.
*/
public static final int ICE_CREAM_SANDWICH_MR1 = 15;
/**
* June 2012: Android 4.1.
*/
public static final int JELLY_BEAN = 16;
/**
* Android 4.2: Moar jelly beans!
*/
public static final int JELLY_BEAN_MR1 = 17;
/**
* Android 4.3: Jelly Bean MR2, the revenge of the beans.
*/
public static final int JELLY_BEAN_MR2 = 18;
/**
* Android 4.4: KitKat, another tasty treat.
*/
public static final int KITKAT = 19;
/**
* Android 4.4W: KitKat for watches, snacks on the run.
*/
public static final int KITKAT_WATCH = 20
public static final int L = 21;
/**
* Lollipop. A flat one with beautiful shadows. But still tasty. Android 5.0
*/
public static final int LOLLIPOP = 21;
/**
* Lollipop with an extra sugar coating on the outside! Android 5.1
*/
public static final int LOLLIPOP_MR1 = 22
/**
* M is for Marshmallow! Android 6.0
*/
public static final int M = 23;
/**
* N is for ¯\_(ツ)_/¯. Android 7.0
*/
public static final int N = 24;
}