I started to explore the new release of Net.Maui combined with Blazor and gRPC Service using the "Net Maui Blazor App Template" as Client and "gRPC Service AspNetCore template" as Server.
So Application is working as well when I'm running under the "Windows platform" with no kind of error, but when I'm running the same application under the "Android platform" the calling to the gRPC server is giving the following error:
Status(StatusCode="Internal", Detail="Error starting gRPC call. WebException: Failed to connect to localhost/127.0.0.1:7215 ConnectException: Failed to connect to localhost/127.0.0.1:7215", DebugException="System.Net.WebException: Failed to connect to localhost/127.0.0.1:7215
Stack Trace:
---> Java.Net.ConnectException: Failed to connect to localhost/127.0.0.1:7215
at Java.Interop.JniEnvironment.InstanceMethods.CallVoidMethod(JniObjectReference instance, JniMethodInfo method, JniArgumentValue* args) in /Users/builder/azdo/_work/2/s/xamarin-android/external/Java.Interop/src/Java.Interop/Java.Interop/JniEnvironment.g.cs:line 11643
at Java.Interop.JniPeerMembers.JniInstanceMethods.InvokeAbstractVoidMethod(String encodedMember, IJavaPeerable self, JniArgumentValue* parameters) in /Users/builder/azdo/_work/2/s/xamarin-android/external/Java.Interop/src/Java.Interop/Java.Interop/JniPeerMembers.JniInstanceMethods_Invoke.cs:line 17
at Javax.Net.Ssl.HttpsURLConnectionInvoker.Connect() in /Users/builder/azdo/_work/2/s/xamarin-android/src/Mono.Android/obj/Release/net6.0/android-31/mcw/Javax.Net.Ssl.HttpsURLConnection.cs:line 535
at Xamarin.Android.Net.AndroidMessageHandler.<>c__DisplayClass122_0.<ConnectAsync>b__0() in /Users/builder/azdo/_work/2/s/xamarin-android/src/Mono.Android/Xamarin.Android.Net/AndroidMessageHandler.cs:line 398
at System.Threading.Tasks.Task.InnerInvoke()
at System.Threading.Tasks.Task.<>c.<.cctor>b__271_0(Object obj)
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
at Xamarin.Android.Net.AndroidMessageHandler.DoProcessRequest(HttpRequestMessage request, URL javaUrl, HttpURLConnection httpConnection, CancellationToken cancellationToken, RequestRedirectionState redirectState) in /Users/builder/azdo/_work/2/s/xamarin-android/src/Mono.Android/Xamarin.Android.Net/AndroidMessageHandler.cs:line 447
--- End of managed Java.Net.ConnectException stack trace ---
java.net.ConnectException: Failed to connect to localhost/127.0.0.1:7215
at com.android.okhttp.internal.io.RealConnection.connectSocket(RealConnection.java:147)
at com.android.okhttp.internal.io.RealConnection.connect(RealConnection.java:116)
at com.android.okhttp.internal.http.StreamAllocation.findConnection(StreamAllocation.java:186)
at com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:128)
at com.android.okhttp.internal.http.StreamAllocation.newStream(StreamAllocation.java:97)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:289)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:232)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:465)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:131)
at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.connect(DelegatingHttpsURLConnection.java:90)
at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:30)
--- End of managed Java.Net.ConnectException stack trace ---
java.net.ConnectException: Failed to connect to localhost/127.0.0.1:7215
at com.android.okhttp.internal.io.RealConnection.connectSocket(RealConnection.java:147)
at com.android.okhttp.internal.io.RealConnection.connect(RealConnection.java:116)
at com.android.okhttp.internal.http.StreamAllocation.findConnection(StreamAllocation.java:186)
at com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:128)
at com.android.okhttp.internal.http.StreamAllocation.newStream(StreamAllocation.java:97)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:289)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:232)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:465)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:131)
at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.connect(DelegatingHttpsURLConnection.java:90)
at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:30)
--- End of inner exception stack trace ---
at Xamarin.Android.Net.AndroidMessageHandler.DoProcessRequest(HttpRequestMessage request, URL javaUrl, HttpURLConnection httpConnection, CancellationToken cancellationToken, RequestRedirectionState redirectState) in /Users/builder/azdo/_work/2/s/xamarin-android/src/Mono.Android/Xamarin.Android.Net/AndroidMessageHandler.cs:line 454
at Xamarin.Android.Net.AndroidMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) in /Users/builder/azdo/_work/2/s/xamarin-android/src/Mono.Android/Xamarin.Android.Net/AndroidMessageHandler.cs:line 329
at Grpc.Net.Client.Web.GrpcWebHandler.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken) in /_/src/Grpc.Net.Client.Web/GrpcWebHandler.cs:line 165
at Grpc.Net.Client.Internal.GrpcCall`2.<RunCall>d__72[[AppsShared.Protos.Credentials, AppsShared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[AppsShared.Protos.LoginStatus, AppsShared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext() in /_/src/Grpc.Net.Client/Internal/GrpcCall.cs:line 469")
Here the settings:
gRPC Client Channel:
builder.Services.AddSingleton(services =>
{
var httpHandler = new GrpcWebHandler(new GrpcWebHandler(GrpcWebMode.GrpcWeb, new HttpClientHandler()));
return GrpcChannel.ForAddress("https://localhost:7215", new GrpcChannelOptions { HttpHandler = httpHandler });
});
gRPC Client Call
var loginer = new Loginer.LoginerClient(channel);
var loginStatus = await loginer.LoginAsync(new Credentials { Password = password , UserName = userName });
Android Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" />
<application android:allowBackup="true" android:icon="@mipmap/appicon" android:roundIcon="@mipmap/appicon_round" android:supportsRtl="true"></application>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
</manifest>
Andoid MainActivity.cs
using Android.App;
using Android.Content.PM;
using Android.OS;
using Android.Runtime;
using Microsoft.Maui;
using Microsoft.Maui.Essentials;
namespace MauiBlazorBase
{
[Activity(Theme = "@style/Maui.SplashTheme", MainLauncher = true,
ConfigurationChanges = ConfigChanges.ScreenSize |
ConfigChanges.Orientation | ConfigChanges.UiMode |
ConfigChanges.ScreenLayout | ConfigChanges.SmallestScreenSize)]
public class MainActivity : MauiAppCompatActivity
{
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Platform.Init(this, savedInstanceState);
}
public override void OnRequestPermissionsResult(int requestCode, string[] permissions,
[GeneratedEnum] Permission[] grantResults)
{
Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
}
Thankyou in advance for tips.
Piercarlo
