Xamarin双应用广播通信异常：休眠应用无法接收广播求助

我的代码实现 #

RFID_App的MainActivity #

using System;

using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.OS;
using RFID_App.Droid;
using Android.Content;
using AndroidX.LocalBroadcastManager.Content;

[assembly: Xamarin.Forms.Dependency(typeof(MainActivity))]
namespace RFID_App.Droid
{
    [Activity(Label = "RFID_App", Icon = "@mipmap/icon", Theme = "@style/MainTheme",
        MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | 
        ConfigChanges.Orientation | ConfigChanges.UiMode | ConfigChanges.ScreenLayout | 
        ConfigChanges.SmallestScreenSize )]
    public class MainActivity : 
        global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity, IBroadcastService
    {

        private static ReceiverRFID receiver;
        private IntentFilter intentFilter = new IntentFilter("eu.logfox.ReceiverMDE");
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            receiver = new ReceiverRFID();

            Xamarin.Essentials.Platform.Init(this, savedInstanceState);
            global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
            LoadApplication(new App());
        }
        public override void OnRequestPermissionsResult(int requestCode, string[]     
            permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
        {
            Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, 
                permissions, grantResults);

            base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
        }

        protected override void OnResume()
        {
            base.OnResume();
            RegisterReceiver(receiver, intentFilter);
        }

        protected override void OnPause()
        {
            UnregisterReceiver(receiver);
            base.OnPause();
        }

    
        public void sendDMC()
        {
            try
            {
                string dmcCode = "]<!n4lkj3n4j3n4lj3n4kj3n4l3k4nk3j4nlkj34nklj3";

                Intent intent = new Intent();
                intent.SetAction("eu.logfox.ReceiverMDE");
                intent.PutExtra("DMC_CODE", dmcCode);
                Context context = Android.App.Application.Context;
                context.SendBroadcast(intent);
            }
            catch(Exception ex)
            {
                System.Console.WriteLine(ex.Message);
            }
    }
}

ReceiverRFID #

namespace RFID_App.Droid
{
    [BroadcastReceiver(Enabled = true, Exported = true)]
    [IntentFilter(new[] { "eu.logfox.ReceiverMDE" })]
    public class ReceiverRFID : BroadcastReceiver
    {
        public override void OnReceive(Context context, Intent intent)
        {
            if(intent.HasExtra("SCAN_REQUEST")) {
                Toast.MakeText(context, intent.GetStringExtra("SCAN_REQUEST"), 
                    ToastLength.Long).Show();
            }
            else
            {
                Toast.MakeText(context, "Any intent", ToastLength.Long).Show();
            }
        }
    }
}

MDE_App的MainActivity #

namespace MDE_App
{
    [Activity(Label = "@string/app_name", Theme = "@style/AppTheme", MainLauncher = 
        true)]
    public class MainActivity : AppCompatActivity
    {

        private static ReceiverMDE receiver;
        private IntentFilter intentFilter = new IntentFilter("eu.logfox.ReceiverRFID");

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            Xamarin.Essentials.Platform.Init(this, savedInstanceState);
            
            SetContentView(Resource.Layout.activity_main);

            receiver = new ReceiverMDE();

            Button btnSend = FindViewById<Button>(Resource.Id.btnSend);

            btnSend.Click += (sender, e) =>
            {
                Intent intent = new Intent();
                intent.SetAction("eu.logfox.ReceiverRFID");
                intent.PutExtra("SCAN_REQUEST", "SCAN");
                intent.AddFlags(ActivityFlags.IncludeStoppedPackages);
                Context context = Android.App.Application.Context;
                context.SendBroadcast(intent);
                //context.SendOrderedBroadcast(intent, "");
            };
        }
        public override void OnRequestPermissionsResult(int requestCode, string[] 
            permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
            {
                Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, 
                    permissions, grantResults);

                base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
            }

        protected override void OnResume()
        {
            base.OnResume();
            RegisterReceiver(receiver, intentFilter);
        }

        protected override void OnPause()
        {
            UnregisterReceiver(receiver);
            base.OnPause();
        }
    }
}

MDE_App的Receiver #

namespace MDE_App
{
    [BroadcastReceiver(Enabled = true, Exported = true)]
    [IntentFilter(new[] { "eu.logfox.ReceiverRFID" })]
    public class ReceiverMDE : BroadcastReceiver
    {
        public override void OnReceive(Context context, Intent 
            intent)
        {
            Toast.MakeText(context, "Received intent!", 
                ToastLength.Short).Show();
        }
    }
}

一、需求可行性 #

完全可行。Android原生支持跨应用组件启动、广播通信，Xamarin作为Android的.NET绑定层，完全可以实现该业务场景。

二、当前代码的核心问题 #

1. 广播Action不匹配：
   • MDE_App发送的广播Action是eu.logfox.ReceiverRFID，但RFID_App的Receiver监听的是eu.logfox.ReceiverMDE，两者不对应，导致请求无法被接收。
   • RFID_App回传结果用的Action是eu.logfox.ReceiverMDE，但MDE_App的Receiver监听的是eu.logfox.ReceiverRFID，同样不匹配，结果无法回传。
2. 唤醒应用的方式错误：仅通过广播唤醒未运行的应用，即使添加IncludeStoppedPackages标记，也无法保证启动RFID_App的主Activity并触发扫描逻辑，必须直接启动目标应用的入口组件。

三、实现方向提示 #

1. 统一广播Action定义
   • 定义两个专属Action：比如com.yourcompany.action.RFID_SCAN_REQUEST（MDE发往RFID的扫描请求）、com.yourcompany.action.RFID_SCAN_RESULT（RFID回传扫描结果），确保发送方与接收方的Action完全一致。
2. 正确启动未运行的RFID_App
   • MDE_App通过PackageManager获取RFID_App主Activity的Intent，调用StartActivity启动，同时在Intent中携带扫描请求标识（如Extra参数），让RFID_App启动后直接触发扫描流程。
3. 优化跨应用广播可靠性
   • 优先使用显式广播：指定接收方的包名+Receiver类名，避免Android 8.0+对隐式广播的限制。
   • 若用隐式广播，需在Manifest中为Receiver声明对应的IntentFilter，同时广播需添加IncludeStoppedPackages标记。
4. RFID_App启动后的逻辑处理
   • RFID_App的入口Activity启动时，检查Intent的Extra参数，判断是否来自MDE_App的扫描请求，若有则直接执行扫描，完成后立即发送结果广播给MDE_App。
5. 兼容性与权限处理
   • Android 12+需添加QUERY_ALL_PACKAGES权限，或在Manifest中用<queries>标签指定允许交互的应用包名，确保MDE_App能找到RFID_App的组件。
   • 保持BroadcastReceiver的Exported = true配置（当前代码已满足）。

内容的提问来源于stack exchange，提问作者DaveR