Xamarin Android ProGuard Enable

Question

i am working on xamarin application. When i enable "ProGuard" in android properties, while building the application, I'm getting the following error:

"java.exe" exited with code1.

proguard cfg file has the following:

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service

Developing Environment:
Visual Studio 2015
Xamarin 4.0.4.4

Answer 1

I had the same issue when enabling ProGuard. By following the advice on this link, I fixed the issue by updating my proguard manually. The steps are fairly easy to follow and they fixed the problem. Hope this helps you.

1. Download the ProGuard zip file available from: https://sourceforge.net/projects/proguard/files/. At time of writing the latest version of ProGuard was 5.3.
2. ProGuard does not have a setup program, so you will need to unzip the file and copy the proguard folder structure into the location identified in the steps below.
3. Launch the SDK Manager and note the path in the top left under the menu options. In my case this was C:\Users\Sahar\AppData\Local\Android\android-sdk. The proguard folder is located in the tools folder of this path (in my case this was C:\Users\Sahar\AppData\Local\Android\android-sdk\tools\proguard).
4. Close any development environments that might be accessing the SDK and rename the proguard folder to proguard.old.
5. Copy the proguard folder of the new version into the tools folder and rename it to proguard if necessary (in my case the copied folder was renamed from proguard5.3).
6. Finally copy the configuration files from the proguard.old folder to the new folder. In my case these were:- proguard-android.txt, proguard-android-optimize.txt and proguard-project.txt.
7. Clean and rebuild your project with ProGuard enabled.

Answer 2

I had a problem where Proguard was removing the Google Play Services libraries from my app.

I had to add the following lines of text to the proguard-android.txt file found in this folder:

/(Path to your Android SDK Folder)/tools/proguard

-keep public class com.google.android.gms.* { public *; }
-dontwarn com.google.android.gms.**

Complete proguard-android.txt File

-keep public class com.google.android.gms.* { public *; }
-dontwarn com.google.android.gms.**

# This is a configuration file for ProGuard.
# http://proguard.sourceforge.net/index.html#manual/usage.html

-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-verbose

# Optimization is turned off by default. Dex does not like code run
# through the ProGuard optimize and preverify steps (and performs some
# of these optimizations on its own).
-dontoptimize
-dontpreverify
# Note that if you want to enable optimization, you cannot just
# include optimization flags in your own project configuration file;
# instead you will need to point to the
# "proguard-android-optimize.txt" file instead of this one from your
# project.properties file.

-keepattributes *Annotation*
-keep public class com.google.vending.licensing.ILicensingService
-keep public class com.android.vending.licensing.ILicensingService

# For native methods, see http://proguard.sourceforge.net/manual/examples.html#native
-keepclasseswithmembernames class * {
    native <methods>;
}

# keep setters in Views so that animations can still work.
# see http://proguard.sourceforge.net/manual/examples.html#beans
-keepclassmembers public class * extends android.view.View {
   void set*(***);
   *** get*();
}

# We want to keep methods in Activity that could be used in the XML attribute onClick
-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keepclassmembers class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator CREATOR;
}

-keepclassmembers class **.R$* {
    public static <fields>;
}

# The support library contains references to newer platform versions.
# Don't warn about those in case this app is linking against an older
# platform version.  We know about them, and they are safe.
-dontwarn android.support.**

# Understand the @Keep support annotation.
-keep class android.support.annotation.Keep

-keep @android.support.annotation.Keep class * {*;}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <methods>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <fields>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <init>(...);
}