Xamarin.Android java.lang.ClassNotFoundException

问题

I'm trying to receive files from external apps using Intent and Action.Send. I chose my app at chooser list and then app trying to start but it crashes:

java.lang.ClassNotFoundException: Didn't find class "net.inlu.Incrypta.MainActivity" on path: DexPathList[[zip file "/data/app/net.inlu.Incrypta-1.apk"],nativeLibraryDirectories=[/data/app-lib/net.inlu.Incrypta-1, /vendor/lib, /system/lib]] at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) at java.lang.ClassLoader.loadClass(ClassLoader.java:497) at java.lang.ClassLoader.loadClass(ClassLoader.java:457) at android.app.Instrumentation.newActivity(Instrumentation.java:1084) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2115) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2248) at android.app.ActivityThread.access$800(ActivityThread.java:138) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1199) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5054) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604) at dalvik.system.NativeStart.main(Native Method)

my manifest file:

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="6" android:versionName="1.0.1" package="net.inlu.Incrypta" android:installLocation="auto">
    <uses-sdk android:minSdkVersion="19" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
    <application android:allowBackup="true" android:label="@string/app_name" android:logo="@drawable/Logo" android:theme="@style/StartTheme" android:windowSoftInputMode="stateVisible|adjustPan" android:icon="@drawable/Logo">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.SEND" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="*/*" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.SEND_MULTIPLE" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="*/*" />
            </intent-filter>
        </activity>
    </application>
</manifest>

I've seen a lot of such issues for Android, but didn't find anuthing exactly for Xamarin.Android. May be anyone knows how to fix it.

MainActivity :

namespace Android.App
{
    [Activity (MainLauncher = true, Icon = "@drawable/Logo", NoHistory = true)]
    public class MainActivity : Activity
    {
        protected override async void OnCreate (Bundle savedInstanceState)
        {
            BootStrapper.RegisterDependencies(new IoCModule());

            Intent intent = Intent;
            string action = intent.Action;
            string type = intent.Type;

            //Xamarin.Insights.Initialize (XamarinInsights.ApiKey, this);
            base.OnCreate (savedInstanceState);
            //SetContentView(Resource.Layout.splash);
            try
            {
                var srv= BootStrapper.Container.Resolve<IServiceManager>();
                var credentials = await srv.ConnectAsync();
                StartActivity(credentials != null ? typeof(BaseActivity) : typeof(LoginActivity));
            }
            catch (Exception)
            {
                StartActivity(typeof(LoginActivity));
            }
        }
    }
} 

回答1:

Try to explicitly change the ACW(Android Callable Wrapper) name of your MainActivity. This can be done multiple ways, but the easiest way would be to use the Name property inside the [Activity] attribute to specify a name. You would then set that name to the name it's looking for.

i.e.

[Activity(Name="net.inlu.incrypta.MainActivity")]

Note: Ensure your namespace follows Java conventions in the sense of a fully qualified name.

EX: com.my.package.ClassName

https://developer.xamarin.com/releases/android/xamarin.android_5/xamarin.android_5.1/#Android_Callable_Wrapper_Naming

来源：https://stackoverflow.com/questions/37947063/xamarin-android-java-lang-classnotfoundexception