How to use proguard optimizer tool with xamarin forms

Question

I want to reduce size of .apk file, so I am checking Enable ProGuard option in Android project's property window but getting compile time error

Error "java.exe" exited with code 1.

I tried few things like

Head size is already 1G.
Android target version is 9.0(Pie).
My Solutions Configuration in Release mode.
Using latest ProGuard file(6.1.1)
Added proguard-android.txt, proguard-android-optimize.txt and proguard-project.txt in new ProGuard file.

Log:

1>------ Rebuild All started: Project: DirectionApp, Configuration: Release Any CPU ------
1>DirectionApp -> D:\New\West\ReadOut\DirectionApp\DirectionApp\DirectionApp\bin\Release\netstandard2.0\DirectionApp.dll
2>------ Rebuild All started: Project: DirectionApp.Android, Configuration: Release Any CPU ------
2>  DirectionApp.Android -> D:\New\West\ReadOut\DirectionApp\DirectionApp\DirectionApp.Android\bin\Release\DirectionApp.Android.dll
2>  No way to resolve conflict between "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" and "mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e". Choosing "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c5614e089" arbitrarily.
2>PROGUARD : warning : md5606e28f7ad4f2edd4892d456667ca4fb.EmdkWrapper: can't find superclass or interface com.symbol.emdk.EMDKManager$EMDKListener
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_EMDKListenerImplementor: can't find superclass or interface com.symbol.emdk.EMDKManager$EMDKListener
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find superclass or interface com.symbol.emdk.EMDKManager$StatusListener
2>PROGUARD : warning : mono.com.symbol.emdk.ProfileManager_DataListenerImplementor: can't find superclass or interface com.symbol.emdk.ProfileManager$DataListener
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find superclass or interface com.symbol.emdk.barcode.BarcodeManager$ScannerConnectionListener
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_DataListenerImplementor: can't find superclass or interface com.symbol.emdk.barcode.Scanner$DataListener
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_StatusListenerImplementor: can't find superclass or interface com.symbol.emdk.barcode.Scanner$StatusListener
2>PROGUARD : warning : mono.com.symbol.emdk.scanandpair.ScanAndPairManager_StatusListenerImplementor: can't find superclass or interface com.symbol.emdk.scanandpair.ScanAndPairManager$StatusListener
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_DataListenerImplementor: can't find superclass or interface com.symbol.emdk.simulscan.SimulScanReader$DataListerner
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_StatusListenerImplementor: can't find superclass or interface com.symbol.emdk.simulscan.SimulScanReader$StatusListerner
2>PROGUARD : warning : md5606e28f7ad4f2edd4892d456667ca4fb.EmdkWrapper: can't find referenced class com.symbol.emdk.EMDKManager$EMDKListener
2>PROGUARD : warning : md5606e28f7ad4f2edd4892d456667ca4fb.EmdkWrapper: can't find referenced class com.symbol.emdk.EMDKManager
2>PROGUARD : warning : md5606e28f7ad4f2edd4892d456667ca4fb.EmdkWrapper: can't find referenced class com.symbol.emdk.EMDKManager
2>PROGUARD : warning : md5606e28f7ad4f2edd4892d456667ca4fb.EmdkWrapper: can't find referenced class com.symbol.emdk.EMDKManager
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_EMDKListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager$EMDKListener
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_EMDKListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_EMDKListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_EMDKListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager$StatusListener
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager$StatusData
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager$StatusData
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.EMDKBase
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.EMDKManager$StatusData
2>PROGUARD : warning : mono.com.symbol.emdk.EMDKManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.EMDKBase
2>PROGUARD : warning : mono.com.symbol.emdk.ProfileManager_DataListenerImplementor: can't find referenced class com.symbol.emdk.ProfileManager$DataListener
2>PROGUARD : warning : mono.com.symbol.emdk.ProfileManager_DataListenerImplementor: can't find referenced class com.symbol.emdk.ProfileManager$ResultData
2>PROGUARD : warning : mono.com.symbol.emdk.ProfileManager_DataListenerImplementor: can't find referenced class com.symbol.emdk.ProfileManager
2>PROGUARD : warning : mono.com.symbol.emdk.ProfileManager_DataListenerImplementor: can't find referenced class com.symbol.emdk.ProfileManager$ResultData
2>PROGUARD : warning : mono.com.symbol.emdk.ProfileManager_DataListenerImplementor: can't find referenced class com.symbol.emdk.ProfileManager$ResultData
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find referenced class com.symbol.emdk.barcode.BarcodeManager$ScannerConnectionListener
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find referenced class com.symbol.emdk.barcode.BarcodeManager$ConnectionState
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find referenced class com.symbol.emdk.barcode.BarcodeManager
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find referenced class com.symbol.emdk.barcode.ScannerInfo
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find referenced class com.symbol.emdk.barcode.BarcodeManager$ConnectionState
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find referenced class com.symbol.emdk.barcode.ScannerInfo
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.BarcodeManager_ScannerConnectionListenerImplementor: can't find referenced class com.symbol.emdk.barcode.BarcodeManager$ConnectionState
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_DataListenerImplementor: can't find referenced class com.symbol.emdk.barcode.Scanner$DataListener
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_DataListenerImplementor: can't find referenced class com.symbol.emdk.barcode.Scanner
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_DataListenerImplementor: can't find referenced class com.symbol.emdk.barcode.ScanDataCollection
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_DataListenerImplementor: can't find referenced class com.symbol.emdk.barcode.ScanDataCollection
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_StatusListenerImplementor: can't find referenced class com.symbol.emdk.barcode.Scanner$StatusListener
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_StatusListenerImplementor: can't find referenced class com.symbol.emdk.barcode.Scanner
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_StatusListenerImplementor: can't find referenced class com.symbol.emdk.barcode.StatusData
2>PROGUARD : warning : mono.com.symbol.emdk.barcode.Scanner_StatusListenerImplementor: can't find referenced class com.symbol.emdk.barcode.StatusData
2>PROGUARD : warning : mono.com.symbol.emdk.scanandpair.ScanAndPairManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.scanandpair.ScanAndPairManager$StatusListener
2>PROGUARD : warning : mono.com.symbol.emdk.scanandpair.ScanAndPairManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.scanandpair.ScanAndPairManager
2>PROGUARD : warning : mono.com.symbol.emdk.scanandpair.ScanAndPairManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.scanandpair.StatusData
2>PROGUARD : warning : mono.com.symbol.emdk.scanandpair.ScanAndPairManager_StatusListenerImplementor: can't find referenced class com.symbol.emdk.scanandpair.StatusData
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_DataListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanReader$DataListerner
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_DataListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanReader
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_DataListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanData
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_DataListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanData
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_StatusListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanReader$StatusListerner
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_StatusListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanReader
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_StatusListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanStatusData
2>PROGUARD : warning : mono.com.symbol.emdk.simulscan.SimulScanReader_StatusListenerImplementor: can't find referenced class com.symbol.emdk.simulscan.SimulScanStatusData
2>PROGUARD : warning : there were 57 unresolved references to classes or interfaces.
2>C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(2550,3): error MSB6006: "java.exe" exited with code 1.
========== Rebuild All: 1 succeeded, 1 failed, 0 skipped ==========

How can I fix this issue? I want to fix above error not only warnings.

Follow this URL and customize your rules based on libraries that you have used. https://learn.microsoft.com/en-us/xamarin/android/deploy-test/release-prep/proguard?tabs=macos — Jaymin, Sep 30 '19 at 08:52
They are telling to add new proguard file but I am confuse, do I need to add proguard.txt or proguard.cfg file and for above logs I am not sure what to add in custom proguard file. — R15, Sep 30 '19 at 08:58
proguard.cfg has to be created and you also can edit the file. — Jaymin, Sep 30 '19 at 09:10
I need to add .cs class file first then need to change extension of that file to .cfg. Now that would be empty file. So I have to fill in this file based on above errors. Could you pl tell me what to write there. — R15, Sep 30 '19 at 09:13
You have to write the rules which exclude the classes which are no use. it looks like this `-dontwarn org.apache.http.**` — Jaymin, Sep 30 '19 at 09:36
Hi, I have added new file with .cfg extension and that file has code `-dontwarn class org.apache.http.**` only. still those warnings and errors are there. Do you have any idea. — R15, Oct 01 '19 at 09:27
you can check this thread first: https://stackoverflow.com/questions/39106663/xamarin-android-proguard-enable — Jessie Zhang -MSFT, Oct 08 '19 at 07:17
@r15 add in proguard file -keep public class mono.com.symbol.emdk.* — Om Infowave Developers, Oct 09 '19 at 06:41
@r15 Are you using the latest version of VS? If yes why are you not using Google's `r8`? Progaurd has gotten old don't you think? — FreakyAli, Oct 09 '19 at 06:51

score 1 · Accepted Answer · answered Oct 16 '19 at 05:08

Follow below steps

First you need to add proguard.cfg to your android project level.
Change proguard.cfg file build action to ProguardConfiguration
Change proguard.cfg file Encoding using Notepad++ to UTF-8

If you are getting warnings then you need to use -dontwarn attribute like below

-dontwarn com.symbol.emdk.**
-dontwarn org.apache.http.**
-dontwarn com.appdynamics.eumagent.runtime.**

You must need to remove/solve warning because that cause above error. Above code will remove all of your warnings.
If you are getting exception after executing your application you need to use -keep attribute. like below for required classes

-keep public class android.support.v7.widget.** { *; }

How to use proguard optimizer tool with xamarin forms

1 Answers1

Linked