Web Service Call Stopped Processing - xamarin.forms

I have a bunch of Xamarin iOS applications running on our Corporate iPhones and iPads. I recently upgraded my Visual Studio and Mac Book Pro to latest release version and my applications are no longer PROCESSING data from my web service correctly. I did not change version of Xamarin.Forms
VS 2017 Version 15.9.13
Xamarin.Forms.2.4.0.282
The web services are http. I have my NSAppTransportSecurityNSAllowsArbitraryLoads
set to allow http.
I am using the flag true to generate the Task.Factory.FromAsync methods in the Web Service Reference.cs file.
I could go on with describing how everything works if anyone needs more info.
Luckily, my Mac Book Pro Simulator has old and new versions of my apps installed in different iPhone/iPad devices for me to test. I installed fiddler to make sure all the requests/responses were the same. My old App in one device works and my new App in a different device fails. Same thing for ALL of my Applications. Old one works and new one fails.
When I review fiddler, the requests and responses are all working the same:
Request is made
App gets an authentication prompt
Authentication happens
Request returns code 200 with the data requested
The only difference in Fiddler is that two of the headers are in a different order: Working one has SOAPAction first and Content-Type next, the one failing has Content-Type and then SOAPAction. I am grasping at straws here because the order of these headers should not matter.
This is for all the applications. The only problem is that my new applications are ignoring the response. It is almost like the endMethod function from the parameter passed to FromAsync is never called.
This is the function call:
public async Task<ProcessLogon> ExecuteSaveLogon(DeviceItem DeviceItem)
{
ResultLogin = new ProcessLogon();
try
{
var ProcessLogon = await Task<WebServiceTrading.ProcessLogon>.Factory.FromAsync(serviceTrading.BeginSaveLogon, serviceTrading.EndSaveLogon, ToServiceTrading(DeviceItem), TaskCreationOptions.None);
ResultLogin = FromServiceTrading(ProcessLogon);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(#"ExecuteSaveLogon ERROR {0}", ex.Message);
}
return ResultLogin;
}
Does anyone know of any DEBUG or LOGGING tools that I could use to find out why my successful response is lost?

Related

Xamarin Android project cannot connect to localhost API

I have been working on this problem for quite some time. I've read the many similar posts and their solutions don't help me (many posts are old and stale). I have a new Xamarin project and a localhost API that I am testing to. Initially I installed our production API locally and it doesn't connect. So I created a smaller test API and have had varying results in connecting. Xamarin Android will not connect with a "Failed to connect to localhost:XXXXX" message. I built a WPF project and get the same results. However I can connect to outside public API's (github) with both. I can connect to my localhost with a Windows forms desktop app and successfully get & post. Postman and httprepl both connect locally and successfully get & post. A couple of the other things the other posts suggested are 1) Client handler to ignore SSL - doesn't work, 2) Use the emulator's browser to connect to localhost - cannot connect. (this might be exposing where the problem really is but not sure).
Also The debugger seems to be behaving oddly. When the debugger gets to the HttpResponseMessageresponse.... line it rarely makes it to the next line so I cannot inspect the statuscode. The block I have below is in a try/catch and rarely makes it to the catch if the connection truly fails. Sometimes it will be caught at the catch and that's how I get the "failed to connect" message. Another developer here has run the project on his computer and gets the same results/errors on his computer.
HttpResponseMessage response = await client.SendAsync(request);
var Statuscode = response.StatusCode;
if (response.IsSuccessStatusCode)
{
var jsonbody = response.Content.ReadAsStringAsync().Result;
var ResponseBody = JsonConvert.DeserializeObject(response.Content.ReadAsStringAsync().Result);
}
else
{
string oops = "Nothing";
}
I seem to be running out of options and am looking for any advice.
Thanks in advance.

IdentityModel.OidcClient library doesn't seem to work with UWP

We are using ASP.NET Identity with IdentityServer4. We've added a Client to use with Azure AD. This works great within a web page, that part is working.
Our end goal is a UWP app, so we found the IdentityModel.OidcClient which has a UWP sample. This sample has two browser classes. We configured HTTPS, but the WabBrowser class now refuses to connect to the site at all. If I change the config to hit https://demo.identityserver.io then it works, but all the other config is the same, so I'm not sure what the problem could be. It shows an error message in the pop up browser that it could not connect.
I looked at the SystemBrowser class, but this logs in fine, then the browser window does not close, and even if we close it, the code doesn't move on to get back a result. Looking at the source, this is not surprising, it calls:
Launcher.LaunchUriAsync(new Uri(options.StartUrl));
and that's all. The RedirectUri is not passed in, and mechanism appears to exist to use it. So, the behaviour we see appears to be the extent of what the class can do.
Looking at the console .NET Core sample, it has a SystemBrowser class that works. I updated the UWP sample to use the Fall Creators Update and was able to bring in the ASP.NET Core dlls needed to compile this code. It sets up a class like this:
public LoopbackHttpListener(int port, string path = null)
{
path = path ?? String.Empty;
if (path.StartsWith("/")) path = path.Substring(1);
_url = $"http://127.0.0.1:{port}/{path}";
_host = new WebHostBuilder()
.UseKestrel()
.UseUrls(_url)
.Configure(Configure)
.Build();
_host.Start();
}
and I can confirm this gets called only once, but even if I hard code an unused IP address, I get an error that the IP is in use.
So, at this stage, the sample that exists for UWP works for the demo server but not for ours (I suspect an HTTPS issue, but that's not the error I get), and importing code that works for a Core sample, does not work either. I've spent a couple of days on this and would appreciate a nudge in the right direction.
So, to recap, the WabBrowser seems the best bet but, for my localhost IdentityServer I get this:
and if I try to use a .NET Core library that works elsewhere, it thinks a port is in use. I suspect I need to work out why WabBrowser can't connect to my local site. I have turned off Fiddler. I can browse to my https URL and get a disco document, in the browser, at https://localhost:44305/.well-known/openid-configuration.
There are extra steps necessary to enable localhost in the Web Authentication Broker -
https://msdn.microsoft.com/en-us/library/windows/desktop/jj658959%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396
This website gave me the fix. Here is a synopsis:
Remove loopback isolation
For security and reliability reasons, UWP applications are not allowed to send requests to the loopback interface. While Visual Studio automatically creates exemptions for debugged apps, this feature won't be helpful in this case, as the authentication broker always executes in a separate process.
If you see this (cryptic) error message in your Windows event logs, then you're likely facing this issue:
AuthHost encountered a navigation error at URL: [...] with StatusCode: 0x800C0005.
One option to fix it is to use the loopack exemption utility developed by Eric Lawrence. It's natively included in Fiddler 4 but can also be downloaded as a standalone software. To allow the authentication broker to communicate with the loopback interface, exempt the applications starting with microsoft.windows.authhost and save your changes:
If everything was properly configured, you should now see the login/consent page returned by your server.

400 Error calling WCF web service from Ripple emulator

I tried to bring an old phonegap 1.0 app into VS tool for Apache Cardova. It calls an old WCF XML web service. When I ran the app in Ripple Emulator using local proxy, I got 400 error from the WCF web service. After some digging around, I found the problem in C:\Users\user_name\AppData\Roaming\npm\node_modules\vs-mda\node_modules\ripple-emulator\lib\server\proxy.js line 85-91:
if (Object.keys(req.body).length > 0) {
if (req.is("json")) {
proxyReqData.body = JSON.stringify(req.body);
} else {
proxyReqData.form = req.body;
}
}
If the request is not json, the code would change it to a form so that an XML web service is not supported by the Ripple proxy. I fixed the code at the place, but it was not picked up by the project build. I also do not have a good way to debug my version of proxy.js. Any suggestion would be appreciated.
I figured out the fix myself. The proxy.js that I found is the right location. However, I had to make several changes to proxy.js to make it work with a soap web service. Note that my changes works when you only call soap web services.
Comment out the line with app.use(express.bodyParser()); and replace with it with raw parser in this post: Expressjs raw body
Replace the code block in my question with just:
proxyReqData.form = req.body;

TodoList sample Bing Maps service returns error with status blank

I am working thru the sample todolist application for the Cordova SDK.
the url is here
https://msdn.microsoft.com/en-us/library/dn832630.aspx
I set up a key on the BING Maps website. I can access the location service sending latitude and longitude thru a standard web browser, pasting in the URL with my key.
However the angular call always fails. What is worse is the error is always blank. no status code no error message. Was thinking it must be CORS.
I have run through the sample and downloaded the code sample and both have the same issue.
For anyone going thru the sample. I have realised today that Angular is evil. They say it is nicely testable javascript with dependancy injection, however it doesn't seem to be too interested in telling you what the error is when you have one, it just fails. Great and noble programming ideas, but without an error message it isn't much good.
Anyhow the fix is that Angular is very strict about json code so the line in services.js for the Bings Maps Service method getAddressFromPosition
it used to work with .get() but this was probably an old version of Angular when the demo was written. I tried using 1.2 but the Ripple emulator didn't like references to browser specific code. So I used the latest 1.3.13 I believe.
This is where to access the Bing location service with the Cordova geolocation coordinates returns Json, but Angular wants them wrapped in JSONP. searching the increasing fragmented web it appeared the error might be CORS no, so a many different people had their JSONP calls in controllers, modules, services, some using $http others $resources. Finally using bits and pieces I got JSONP to work with $resources and to plug it into the $promise the call from the controller requires. I used a static Url with Coordinates I knew worked, so you will have to use the :param angular notation to put those back in. Hope it helps someone.
So change to:
getAddressFromPosition: function (position) {
var resource = $resource(url, {}, {
jsonp_query: {
method: 'JSONP'
}
});
return resource.jsonp_query().$promise.then(function (response) {
return response.resourceSets[0].resources[0].address.formattedAddress;
}, function (error) {
return position.coords.latitude + "," + position.coords.longitude
});
edit:
I put the above in and it worked. However the problem was for some reason, perhaps thru debugging, another instance of the app was deployed on another port in ripple. This then change the app to run on this new port. The initial port was 4400. The problem is that and $http or $resource calls in angular have to go thru this emulator, and the emulator was seeing this as cross domain, unless it is configured to the same port the app is running under.
so Url:
http://localhost:4409/index.html?enableripple=cordova-3.0.0-iPhone5
then in the Settings Div dropdown on the right side, the Proxy Port must also be set to 4409 or else the browser will complain that the $http request is cross-domain, before the emulator actually executes it to query Azure mobile service or Bing maps.
So this was very frustrating. However VS Cordova has definately reduced the amount of bits you have to configure to make hybrid mobile apps, there are still little glitches like this which can trip you up. I assumed it was something with angular, because there was no error messages, but in Chrome in the Dev Tools console that was where the error was, and after some googling it was plain that it was the ripple emulator running on a different port than its proxy was not allowing the call to be forwarded on due to Access-Control-Allow not being set.

Why won't OAuth work on web server?

I have an ASP.Net web application running on Windows Server 2012, and need to make calls to social networking sites using oauth to generate some of the page content. Everything works on my development machine, but I can't even get a single response back ("unable to connect to the remote server" error).
I disabled the firewall to test that. No luck. I created a console application to test it that way. A simple HttpWebRequest will get the html for any page I throw at it, but not any oauth request. I've used different libraries to try to achieve this, including Linq2Twitter, Spring.Social, and HigLabo. All work locally, but not on the server. I've found nothing useful in the server event log.
Can anyone give me some clues what might be happening?
EDIT: Here's some code I'm using with the HigLabo library to try to retrieve the user timeline.
using HigLabo.Net.Twitter;
var cl = new TwitterClient(consumerKey, consumerSecret, accessToken, accessTokenSecret);
var rr = cl.GetHomeTimeline();
foreach (var r in rr)
{
//Console.WriteLine(r.CreatedAt + ":" + r.Text);
}
I'm aware that accessToken & accessTokenSecret aren't/shouldn't be necessary for a simple timeline read, but this is just to make sure it works first.
This turned out to be a firewall issue, as had been suspected. But not the server firewall. This was a problem with the ISP. They had an internal firewall that was blocking all traffic to/from the social network sites. They were able to resolve it quickly with a phonecall, but it was not a coding or configuration error on my part.

Resources