下面具体说一说怎么样让SDK2.3下的proguard.cfg文件起作用,先来看看proguard.cfg的内容:
-optimizationpasses 5-dontusemixedcaseclassnames-dontskipnonpubliclibraryclasses-dontpreverify-verbose-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*-keep public class * extends android.app.Activity-keep public class * extends android.app.Application-keep public class * extends android.app.Service-keep public class * extends android.content.BroadcastReceiver-keep public class * extends android.content.ContentProvider-keep public class com.android.vending.licensing.ILicensingService-keepclasseswithmembernames class * {native <methods>;}-keepclasseswithmembernames class * {public <init>(android.content.Context, android.util.AttributeSet);}-keepclasseswithmembernames class * {public <init>(android.content.Context, android.util.AttributeSet, int);}-keepclassmembers enum * {public static **[] values();public static ** valueOf(java.lang.String);}-keep class * implements android.os.Parcelable {public static final android.os.Parcelable$Creator *;}
从脚本中可以看到,混淆中保留了继承自Activity、Service、Application、BroadcastReceiver、ContentProvider等基本组件以及com.android.vending.licensing.ILicensingService,并保留了所有的Native变量名及类名,所有类中部分以设定了固定参数格式的构造函数,枚举等等。(详细信息请参考<proguard_path>/examples中的例子及注释。)
让proguard.cfg起作用的做法很简单,就是在eclipse自动生成的default.properties文件中加上一句“proguard.config=proguard.cfg”就可以了,完整的default.properties文件应该如下:
# This file is automatically generated by Android Tools.# Do not modify this file -- YOUR CHANGES WILL BE ERASED!## This file must be checked in Version Control Systems.## To customize properties used by the Ant build system use,# "build.properties", and override values to adapt the script to your# project structure.# Project target.target=android-9proguard.config=proguard.cfg
大功告成,正常的编译签名后就可以防止代码被反编译了。反编译经过代码混淆的apk得到的代码应该类似于下面的效果,是很难看懂的:
如果您使用的是2.3之前的SDK版本也没关系,把上面的proguard.cfg文件复制一份放到项目中,然后进行相同的操作即可。