Xamarin java绑定库编译错误

Question

我有一个使用 Android 库的 android 应用程序 (Java)。 一切正常，但我需要将此应用程序包装到 Xamarin 应用程序中。所以我决定将这个应用程序转换为第二个 Android 库。 我创建了我的 Xamarin Android 应用程序和一个 Android Java 绑定库项目，其中我将两个 .aar 文件添加到“Jars”文件夹中。

当我尝试编译这个绑定项目时，问题就来了。我遇到了很多这样的错误：

/.../obj/Release/generated/src/Com.Google.Common.Util.Concurrent.ForwardingListenableFuture.cs(17,17): Error CS0102: The type `Com.Google.Common.Util.Concurrent.ForwardingListenableFutureInvoker' already contains a definition for `id_delegate' (CS0102)

当我打开生成的 ForwardingListenableFuture.cs 文件时，有以下代码：

[global::Android.Runtime.Register ("com/google/common/util/concurrent/ForwardingListenableFuture", DoNotGenerateAcw=true)]
internal partial class ForwardingListenableFutureInvoker : ForwardingListenableFuture, global::Com.Google.Common.Util.Concurrent.IListenableFuture {

        public ForwardingListenableFutureInvoker (IntPtr handle, JniHandleOwnership transfer) : base (handle, transfer) {}

        protected override global::System.Type ThresholdType {
            get { return typeof (ForwardingListenableFutureInvoker); }
        }

        static IntPtr id_delegate;
        // Metadata.xml XPath method reference: path="/api/package[@name='com.google.common.util.concurrent']/class[@name='ForwardingListenableFuture']/method[@name='delegate' and count(parameter)=0]"
        [Register ("delegate", "()Lcom/google/common/util/concurrent/ListenableFuture;", "GetDelegateHandler")]
        protected override global::Com.Google.Common.Util.Concurrent.IListenableFuture Delegate ()
        {
            if (id_delegate == IntPtr.Zero)
                id_delegate = JNIEnv.GetMethodID (class_ref, "delegate", "()Lcom/google/common/util/concurrent/ListenableFuture;");
            return global::Java.Lang.Object.GetObject<global::Com.Google.Common.Util.Concurrent.IListenableFuture> (JNIEnv.CallObjectMethod  (Handle, id_delegate), JniHandleOwnership.TransferLocalRef);
        }

        static IntPtr id_delegate;
        // Metadata.xml XPath method reference: path="/api/package[@name='com.google.common.util.concurrent']/class[@name='ForwardingFuture']/method[@name='delegate' and count(parameter)=0]"
        [Register ("delegate", "()Ljava/util/concurrent/Future;", "GetDelegateHandler")]
        protected override global::Java.Util.Concurrent.IFuture Delegate ()
        {
            if (id_delegate == IntPtr.Zero)
                id_delegate = JNIEnv.GetMethodID (class_ref, "delegate", "()Ljava/util/concurrent/Future;");
            return global::Java.Lang.Object.GetObject<global::Java.Util.Concurrent.IFuture> (JNIEnv.CallObjectMethod  (Handle, id_delegate), JniHandleOwnership.TransferLocalRef);
        }

        static IntPtr id_delegate;
        // Metadata.xml XPath method reference: path="/api/package[@name='com.google.common.collect']/class[@name='ForwardingObject']/method[@name='delegate' and count(parameter)=0]"
        [Register ("delegate", "()Ljava/lang/Object;", "GetDelegateHandler")]
        protected override global::Java.Lang.Object Delegate ()
        {
            if (id_delegate == IntPtr.Zero)
                id_delegate = JNIEnv.GetMethodID (class_ref, "delegate", "()Ljava/lang/Object;");
            return global::Java.Lang.Object.GetObject<global::Java.Lang.Object> (JNIEnv.CallObjectMethod  (Handle, id_delegate), JniHandleOwnership.TransferLocalRef);
        }

    }

确实，“id_delegate”是重复的..

我也有与第一个 .aar 相关的警告（不是应用程序）：

/../JARTOXML: Warning J2X9001: Couldn't load class com/company/project/controllers/activities/MenuActivity : java.lang.NoClassDefFoundError: android/support/v4/app/FragmentActivity (J2X9001)

Answer 1

好的，我通过将 remove-node 语句添加到 Metadata.xml 解决了第一部分的错误。

对于第二部分，添加对 Xamarin.Android.Support.v4 的引用解决了问题。