Xamarin Android Proguard-不支持的类版本号52.0
我试图在我的Xamarin.Android项目中使用Proguard，但编译失败，错误为Xamarin Android Proguard-不支持的类版本号52.0,xamarin,xamarin.android,android-proguard,Xamarin,Xamarin.android,Android Proguard,我试图在我的Xamarin.Android项目中使用Proguard，但编译失败，错误为不支持的类版本号[52.0]（最大51.0，Java 1.7） 我从中看到，可能是Java7和Java8不匹配，更确切地说，proguard的一些版本不支持Java8。然而，在Xamarin Preferences->SDK位置，Java SDK指向JDK 7:/Library/Java/JavaVirtualMachines/jdk1.7.079.JDK/Contents/Home 是否有任何地方可以更精确
不支持的类版本号[52.0]（最大51.0，Java 1.7）/Library/Java/JavaVirtualMachines/jdk1.7.079.JDK/Contents/Home您需要使用以下最新版本的proguard更新默认的Android SDK
proguard.jarAndroid sdk\tools\proguardproguard在我的Windows 10 x64和visual studio 2015上，我也面临同样的问题。我已经在VisualStudio的android设置下将JDK路径设置为JDK 1.8
工具->选项->xamarin->java开发工具包位置。它指向“C:\Program Files（x86）\Java\jdk1.7.0\u 55”，我把它指向“C:\Program Files\Java\jdk1.8.0\u 31”，问题已经解决。简单答案 根据文档，您需要更新proguard版本（从支持Java 8的it开始），并确保您使用的是jdk1.8 JDK 1.8-API 24之前的版本+ JDK 1.7-API 23之前的版本 JDK 1.6-API 20之前的版本 如何从软件包控制台更新编写此命令
PM> Install-Package name.atsushieno.proguard.facebook
如果您同时使用google play服务，我遇到一个问题，Proguard将google play服务库从我的应用程序中删除 除了上面的回答之外，我还必须将以下几行文本添加到该文件夹中的
proguard android.txt/（Android SDK文件夹路径）/tools/proguard-keep public class com.google.android.gms.* { public *; }
-dontwarn com.google.android.gms.**
-保持公共类com.google.android.gms.*{public*；}
-dontwarn com.google.android.gms**
#这是ProGuard的配置文件。
# http://proguard.sourceforge.net/index.html#manual/usage.html
-dontusemixedcaseclassnames
-DontskipnonPublicLibraryClass
-冗长的
#默认情况下，优化处于关闭状态。Dex不喜欢代码运行
#通过ProGuard优化和预验证步骤（并执行一些
#这些优化的一部分）。
-dontoptimize
-不要翻转
#请注意，如果要启用优化，则不能
#在您自己的项目配置文件中包含优化标志；
#相反，您需要指向
#“proguard android optimize.txt”文件，而不是您的
#project.properties文件。
-keepattributes*注释*
-保持公共类com.google.vending.licensing.ILicensingService
-保持公共类com.android.vending.licensing.ILicensingService
#有关本机方法，请参见http://proguard.sourceforge.net/manual/examples.html#native
-KeepClassSwithMemberNames类*{
本地人；
}
#使setter保持在视图中
-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>(...);
}
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Xamarin\Android\proguard\lib
-dontwarn com.symbol.emdk.**
-dontwarn org.apache.http.**
-dontwarn com.appdynamics.eumagent.runtime.**
-keep public class android.support.v7.widget.** { *; }