Xamarin forms issue with Android 9

Question

I am using httpclient in my application that was initally design for andriod 7 but in andriod 9 it says here

https://developer.android.com/about/versions/marshmallow/android-6.0-changes#behavior-apache-http-client

I am using xamrain forms and this is the code I am using to connect

HttpClient _client;

    public RestServices()
    {
        _client = new HttpClient();
    }

public async Task<List<BomLookupModel>> GetBomLookups()
{

        List<BomLookupModel> _result = new List<BomLookupModel>();
        try
        {
            var uri = new Uri(string.Format(Constants.GetBomLookupInfo, string.Empty));

            var response = await _client.GetAsync(uri);
            if (response.IsSuccessStatusCode)
            {
                var content = await response.Content.ReadAsStringAsync();
                _result = JsonConvert.DeserializeObject<List<BomLookupModel>>(content);
            }
        }
        catch(Exception ex)
        {

          Log.Warn(ex.ToString());  
        }
        return _result.ToList();
    }

What must I change to get my code to work with a json fetch in android 9 on Xamrian forms? Has anyone else come across this work in Android 7 but according to that article it may not work in Andriod 9.

It just crashes out with a java.io error. The error I get is no firewall is active and my phone is in developer mode any ideas?

192.168.0.13 not permitted at Java.Interop.JniEnvironment+InstanceMethods.CallVoidMethod

{Java.IO.IOException: Cleartext HTTP traffic to 192.168.0.13 not permitted at Java.Interop.JniEnvironment+InstanceMethods.CallVoidMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniMethodInfo method, Java.Interop.JniArgumentValue* args) [0x00069] in <9ed4c1a7b8844cdcb5330cc881c1cd6a>:0 at Java.Interop.JniPeerMembers+JniInstanceMethods.InvokeAbstractVoidMethod (System.String encodedMember, Java.Interop.IJavaPeerable self, Java.Interop.JniArgumentValue* parameters) [0x00014] in <9ed4c1a7b8844cdcb5330cc881c1cd6a>:0 at Java.Net.HttpURLConnectionInvoker.Connect () [0x0000a] in :0 at Xamarin.Android.Net.AndroidClientHandler+<>c__DisplayClass44_0.b__0 () [0x0005a] in :0 at System.Threading.Tasks.Task.InnerInvoke () [0x0000f] in <3a61d48d66dd458fa0b64990b6c8f8cc>:0 at System.Threading.Tasks.Task.Execute () [0x00000] in <3a61d48d66dd458fa0b64990b6c8f8cc>:0 --- End of stack trace from previous location where exception was thrown ---

at Xamarin.Android.Net.AndroidClientHandler.DoProcessRequest (System.Net.Http.HttpRequestMessage request, Java.Net.URL javaUrl, Java.Net.HttpURLConnection httpConnection, System.Threading.CancellationToken cancellationToken, Xamarin.Android.Net.AndroidClientHandler+RequestRedirectionState redirectState) [0x0012e] in :0 at Xamarin.Android.Net.AndroidClientHandler.SendAsync (System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) [0x002be] in :0 at System.Net.Http.HttpClient.SendAsyncWorker (System.Net.Http.HttpRequestMessage request, System.Net.Http.HttpCompletionOption completionOption, System.Threading.CancellationToken cancellationToken) [0x000ca] in <162fad71ed6e4a3cb7598d196d170e1b>:0 at FuelStockApp.RESTApi.FuelRestServices.GetBomLookups () [0x00065] in D:\Git\FuelStockAppLive\FuelStockApp\FuelStockApp\FuelRestServices.cs:72 --- End of managed Java.IO.IOException stack trace --- java.io.IOException: Cleartext HTTP traffic to 192.168.0.13 not permitted at com.android.okhttp.HttpHandler$CleartextURLFilter.checkURLPermitted(HttpHandler.java:115) at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:458) at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:127) }

Edit 2

I have tried the following with Xamrian forms andriod but its not allowing me to still access the http://192 address

 <?xml version="1.0" encoding="utf-8"?> <manifest
 xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.companyname.StockApp" android:installLocation="auto"
 android:versionCode="2" android:versionName="1.0">     <uses-sdk
 android:minSdkVersion="24" android:targetSdkVersion="28" />
    <uses-permission
 android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_SETTINGS" />
    <uses-permission android:name="android.permission.WRITE_SMS" />
    <uses-permission
 android:name="android.permission.WRITE_USER_DICTIONARY" />
    <application android:label="StockApp.Android"></application>
    <uses-permission
 android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission
 android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET" />  
 <application

         android:usesCleartextTraffic="true">

   </application> </manifest>

While the layout of the xml file is true for android its not true for Xam forms @SushiHangover — c-sharp-and-swiftui-devni, Jun 12 '19 at 21:05
You have to make those changes in your Xamarin.Android project, not the NetStd2/Forms project as it is platform dependent — SushiHangover, Jun 12 '19 at 21:33
@SushiHangover ok but what about beacuse i have a 192.168 address and not a domain how would the format then go. — c-sharp-and-swiftui-devni, Jun 12 '19 at 21:41
@SushiHangover I have done this and its still not working 192.168.0.13 10.0.2.2 10.0.3.2 — c-sharp-and-swiftui-devni, Jun 12 '19 at 21:53
Since you are using an xml to define the domains, have you add the `NetworkSecurityConfig` link to that file (Resources/xml/??????.xml) in your manifest or Application attribute? — SushiHangover, Jun 12 '19 at 22:03
@SushiHangover yes and set the build type to andriod resource and also allowed internet permissions — c-sharp-and-swiftui-devni, Jun 12 '19 at 22:04

Xamarin forms issue with Android 9

0 Answers0