Unable to get provider (ClassNotFoundException) Xamarin

问题

I am working on a Solution in Xamarin which contains at least 4 different Android Applications.

My Goal is to create a shared content provider for all of these four apps so that I can have the Master data in one place (If an application updates that data, I can get that updated version in another app).

In Visual Studio, I have create a PCL project where I have defined the Content provider (which I can reference in all applications and do the CRUD operations).

My Content Provider is as follows:

namespace com.cybertron.android.Provider
{
    public class SectionProvider : ContentProvider
    {
        SectionDatabase sectDb;
        public const string AUTHORITY = "com.cybertron.android.Provider.SectionProvider";
        public const string SECTIONS_MIME_TYPE = ContentResolver.CursorDirBaseType + "/vnd.com.cybertron.android.sections";
        public const string SECTION_MIME_TYPE = ContentResolver.CursorItemBaseType + "/vnd.com.cybertron.android.section";
        static string BASE_PATH = "sections";
        static UriMatcher uriMatcher = BuildUriMatcher();
        public static readonly Android.Net.Uri CONTENT_URI = Android.Net.Uri.Parse("content://" + AUTHORITY + "/" + BASE_PATH);
        const int GET_ALL = 0;
        const int GET_ONE = 1;
        public static class SectionConsts
        {
            public const string SectNo = "SectNo";
            public const string KeyPos = "Key";
            public const string Date = "Date";
            public const string UnitID = "UnitID";
        }

        static UriMatcher BuildUriMatcher()
        {
            var matcher = new UriMatcher(UriMatcher.NoMatch);

            matcher.AddURI(AUTHORITY, BASE_PATH, GET_ALL); 
            matcher.AddURI(AUTHORITY, BASE_PATH + "/#", GET_ONE);
            return matcher;
        }
        public override bool OnCreate()
        {
            sectDb = new SectionDatabase(Context);
            return true;
        }        

        public override string GetType(Android.Net.Uri uri)
        {
            switch (uriMatcher.Match(uri))
            {
                case GET_ALL:
                    return SECTIONS_MIME_TYPE; // list
                case GET_ONE:
                    return SECTION_MIME_TYPE; // single item
                default:
                    throw new Java.Lang.IllegalArgumentException("Unknown Uri: " + uri);
            }
        } 
.
.
.        
    }
}

I have referenced my project in my Xamarin Application project. I did not put the ContentProvider attribute because I learned that gives out INSALL_FAILED_CONFLICT error if two applications use the same one. Instead I put that in the manifest file as follows:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
                package="com.cybertron.android.bluecork"
                android:versionCode="1" android:versionName="1.0">
  <uses-sdk android:minSdkVersion="16" />
  <application android:label="com.cybertron.android.bluecork.blueapp">
    <provider
          android:name="com.cybertron.android.Provider.SectionProvider"
          android:authorities="com.cybertron.android.Provider.SectionProvider"
          android:exported="true" />
  </application>          
</manifest>

When I try to debug this application I get an error up front (when the app starts in the emulator)

java.lang.RuntimeException: Unable to get provider com.cybertron.android.Provider.SectionProvider:
java.lang.ClassNotFoundException: Didn't find class com.cybertron.android.Provider.SectionProvider on path: DexPathList......

Can anyone tell me why I am getting this error. Secondly, I would like to know if it is possible for multiple applications to share one database on Android Systems?

Thanks,

来源：https://stackoverflow.com/questions/45074287/unable-to-get-provider-classnotfoundexception-xamarin