广播接收器不在Xamarin Forms中工作

Posted 2021-04-06

我试图在Xamarin Forms中实现广播消息接收器但无法接收任何消息，我不确定出了什么问题，下面是我的主要活动代码

[Activity(Label = "HeloApp.android", Theme = "@style/MyTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        protected override void OnCreate(Bundle bundle)
        {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(bundle);

            global::Xamarin.Forms.Forms.Init(this, bundle);

            LoadApplication(new App());
            Connector.Instance.Initialize(this, "151265380086941117", "E862D6D7D70ED2C3729CB24BC3AB40753A52EAB0");
            MeasurementReceiver heartRateRec = new MeasurementReceiver();
            RegisterReceiver(heartRateRec, new IntentFilter("com.worldgn.connector.HR_MEASUREMENT"));
        }

    }

    [BroadcastReceiver(Enabled = true)]
    [IntentFilter(new[] { "com.worldgn.connector.HR_MEASUREMENT" })]
    public class MeasurementReceiver : BroadcastReceiver
    {
        public override void OnReceive(Context context, Intent intent)
        {
            if (intent.Action.Equals("com.worldgn.connector.HR_MEASUREMENT"))
            {
                var heartRate = intent.GetStringExtra("HR_MEASUREMENT");
            }
        }
    }

以下是我从xamarin表单方面启动广播接收器的方式。我不确定广播接收器如何在给定的情况下工作，因为我第一次这样做。

[XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class BLEDevices : ContentPage
    {
        public BLEDevices()
        {
            InitializeComponent(); 
        }

        private void SearchBLE_Clicked(object sender, EventArgs e)
        {
            Connector.Instance.Scan(new DeviceScanCallBack());
        }

        private void Disconnect_Clicked(object sender, EventArgs e)
        {
            Connector.Instance.UnbindDevice();
        }
    }

    public class DeviceScanCallBack : Java.Lang.Object, IScanCallBack
    {
        public void OnLedeviceFound(DeviceItem p0)
        {
            Connector.Instance.Connect(p0);
            App.Current.MainPage.DisplayAlert("Information", "Device connected successfully.", "Cancel");

            //Here i am trying to initiate the broadcast receiver
            Connector.Instance.MeasureHR();
        }

        public void OnPairedDeviceNotFound()
        {
            App.Current.MainPage.DisplayAlert("Warning", "Please disconnect the device first.", "OK");
        }

        public void OnScanFinished()
        {

        }

        public void OnScanStarted()
        {

        }
    }

我想要实现的是在调试模式下点击OnReceive方法，这将解决我的所有问题。

任何帮助赞赏。谢谢

答案

我正在从xamarin表单方面启动广播接收器。

这意味着你想要使用原生API（Android平台API SendBroadcast），是不是？如果它是正确的，在xamarin.Android你可以使用DependencyService来实现它。

四个步骤：

1.定义PCL中的接口，你称之为xamarin forms side：

   public interface ISend
    {
        void Send();
    }

2.实现Android平台：

class SendImpl : ISend
{
    public void Send()
    {
        Intent intent = new Intent("com.worldgn.connector.HR_MEASUREMENT");
        intent.PutExtra("HR_MEASUREMENT","value");
        Forms.Context.SendBroadcast(intent);
    }
}

3.使用DependencyService注册，在命名空间上方添加：

[assembly:Dependency(typeof(SendImpl))]

4.拨打PCL中的DependencyService，然后你将获得OnReceive：

public void OnLedeviceFound(DeviceItem p0)
{
    Connector.Instance.Connect(p0);
    App.Current.MainPage.DisplayAlert("Information", "Device connected successfully.", "Cancel");

    //Here i am trying to initiate the broadcast receiver
    DependencyService.Get<ISend>().Send();
    Connector.Instance.MeasureHR();
}