Xposed原理简介
Xposed基于两个部分，底层是替换/system/bin/app_process，增加Hook替换函数的接口，主体框架为XposedBridge，由de.robv.android.xposed.XposedBridge的main方法入口。
开发一个基于Xposed的插件
这里以一个动态监测sendTextMessage的Demo为例介绍如何基于Xposed框架实现一个插件。
AndroidManifest.xml
Xposed会读取Application下的相关meta-data，例如这里：
<meta-data android:value="true" android:name="xposedmodule"/> <meta-data android:value="2.1*" android:name="xposedminversion"/> <meta-data android:value="Test for Xposed." android:name="xposeddescription"/>IXposedHookLoadPackage IXposedHookLoadPackage接口的handleLoadPackage方法在Package Load前调用。
public class Main implements IXposedHookLoadPackage { public void handleLoadPackage(final LoadPackageParam pkg) throws Throwable { XposedBridge.log("Loaded app: " + pkg.packageName);在测试程序运行后输出日志如下：
09-17 17:25:11.319: I/Xposed(13475): Loaded app: com.example.smshookfindAndHookMethod
实现对指定类的指定方法进行Hook，并且通过override beforeHookedMethod和afterHookedMethod来记录和改变原始行为。
findAndHookMethod("android.telephony.SmsManager", pkg.classLoader, "sendTextMessage", String.class, String.class, String.class, PendingIntent.class, PendingIntent.class, new XC_MethodHook() { protected void beforeHookedMethod(MethodHookParam param) throws Throwable { XposedBridge.log("before send"); Object[] args = param.args; XposedBridge.log(args[0] + ": " + args[2]); } protected void afterHookedMethod(MethodHookParam param) throws Throwable { XposedBridge.log("after send"); } });在测试程序点击发送短信后输出日志如下：
09-17 17:25:12.150: I/Xposed(13475): before send 09-17 17:25:12.150: I/Xposed(13475): 10086: test hello world. 09-17 17:25:12.160: I/Xposed(13475): after send
