Xamarin forms app Connection to Asp.net core web Api-CodePudding

I have a xamarin forms app that uses a (local) web api (using asp.net core) to connect to Sql Server Database. i tried the demo provided here https://docs.microsoft.com/en-us/aspnet/web-api/overview/advanced/calling-a-web-api-from-a-net-client to make a client api calls but it uses a console app instead of mobile app and it worked fine.

using both Microsoft.AspNet.WebApi.Client and Newtonsoft.Json Nuget Packages

Xamarin forms client code

 client.BaseAddress = new Uri("http://myIP:port/");

            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(
                new MediaTypeWithQualityHeaderValue("application/json"));
            try
            {
                HttpResponseMessage response = await client.PostAsJsonAsync("api/users", user);
                response.EnsureSuccessStatusCode();
                return response.IsSuccessStatusCode;
            }
            catch (Exception ex)
            {

                Debug.WriteLine("Post Api Exception Msg: "   ex.Message, Class_Name);
                return false;
            }

and my web-Api code

public IActionResult Post([FromBody] User user)
        {
        if(!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }
    
    bool result= repository.Create(user);
    if(result)
    {
        return Ok();
    }
    else
    {
        return StatusCode(500);
    }
}

and i have tested the api code and it's working fine. but whenever i try to make calls from my xamarin app

first) i placed a breake point in the web-api code it never gets hit

second) i keep getting the exception

[monodroid-net]   --- End of managed Java.Net.SocketException stack trace ---
[monodroid-net] java.net.SocketException: Socket closed
[monodroid-net]     at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:394)
[monodroid-net]     at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230)
[monodroid-net]     at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212)
[monodroid-net]     at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436)
[monodroid-net]     at java.net.Socket.connect(Socket.java:621)
[monodroid-net]     at com.android.okhttp.internal.Platform.connectSocket(Platform.java:145)
[monodroid-net]     at com.android.okhttp.internal.io.RealConnection.connectSocket(RealConnection.java:141)
[monodroid-net]     at com.android.okhttp.internal.io.RealConnection.connect(RealConnection.java:112)
[monodroid-net]     at com.android.okhttp.internal.http.StreamAllocation.findConnection(StreamAllocation.java:184)
[monodroid-net]     at com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:126)
[monodroid-net]     at com.android.okhttp.internal.http.StreamAllocation.newStream(StreamAllocation.java:95)
[monodroid-net]     at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:281)
[monodroid-net]     at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:224)
[monodroid-net]     at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:461)
[monodroid-net]     at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:127)

I think it means that there is a problem with the connection socket but I have no idea what the problem is and how to resolve it.

CodePudding user response：

In order to access your location machine's web API in the android emulator, you must use the IP 10.0.2.2, see the link below for assistance

https://developer.android.com/studio/run/emulator-networking#networkaddresses

CodePudding user response：

You need change this:

client.BaseAddress = new Uri("http://10.0.2.2:port/");

instead of:

client.BaseAddress = new Uri("http://myIP:port/");

for more information, see the official documentation: https://docs.microsoft.com/en-us/xamarin/cross-platform/deploy-test/connect-to-local-web-services