So I've been working on a xamarin PCL project targeting android and windows store app and I've had this issue for about two weeks now. One of the very first things this app does is to make an http request to a yahoo service when the user tries to search for something.
Now, on the windows store app project, this works just fine. However, whenever I'm debugging the android project, this fails miserably. It times out and I get a TaskAbortedException.
I've navigated with the browser within the android emulator to the restful service url and I do get a response in the browser but nothing when I make the http request. I have tried everything I could think of but no cigar. I have researched this for weeks now and I have yet to find an answer. It should be noted that I'm making the request within the PCL project with HttpClient.
Here's the code where this happens:
var queryUrl = string.Format(QUERY_URL_TEMPLATE, TickerSearch);
try
{
var requestTask = httpClient.GetStringAsync(queryUrl);
requestTask.ContinueWith(t =>
{
var responseDto = JsonConvert.DeserializeObject<TickerSearchResultDto>(t.Result);
TickerSearchResults = responseDto.ResultSet.Result;
});
}
catch (Exception ex)
{
}
Any help is greatly appreciated.
Related
I have a finished application which I would like to make available to run on the iOS and Android platforms. I have tested the application as much as possible and it works without problem. But I know there is always the chance that something might go wrong and I could get an exception.
My question is how can I deal with this or what should I do. What happens on the phone, if a Forms application is deployed and there is an exception.
Would appreciate any advice or even links as to how this is handled.
If an exception is thrown and not handled by your code, the app will stop working (i.e. crash).
In order to handle these crashes we are using MS AppCenter (the successor to HockeyApp/Xamarin AppInsights).
You'll have to create a project there (one for each platform), and add the NuGet package to your projects. Afterwards you can initialize it with
AppCenter.Start("ios={Your App Secret};android={Your App Secret}",
typeof(Crashes)); // you'll get the app secrets from appcenter.ms
Crashes will be logged to AppCenter now and you'll be informed whenever there is a new crash.
Please note that it's best practice (if not required by law), that you ask the user for consent before sending the crash report (see here). You are using the delegate Crashes.ShouldAwaitUserConfirmation for that matter. You could for example show an action sheet with Acr.UserDialogs
private bool AwaitUserConfirmation()
{
// you should of course use your own strings
UserDialogs.Instance.ActionSheet(
new ActionSheetConfig
{
Title = "Oopsie",
Message = "The app crashed. Send crash to developers.",
Options = new List<ActionSheetOption>
{
new ActionSheetOption("Sure", () => Crashes.NotifyUserConfirmation(UserConfirmation.Send)),
new ActionSheetOption("Yepp, and don't bug be again.", () => Crashes.NotifyUserConfirmation(UserConfirmation.AlwaysSend)),
new ActionSheetOption("Nope", () => Crashes.NotifyUserConfirmation(UserConfirmation.DontSend))
}
});
return true;
}
I'm building an app with Xamarin Forms. I have no issues with Android, but when I attempt to simulate or deploy the iOS app, my HttpClient can't seem to connect to the server. After the timeout expires, I get a TaskCanceledException.
The HttpClient is actually used in a separate project that is referenced by the iOS app, if that matters. Here's my usage:
string serviceUri = service + methodName;
HttpRequestMessage request = new HttpRequestMessage(methodRequestType, serviceUri)
{
Content = new StringContent(content, Encoding.UTF8, "application/json")
};
HttpResponseMessage response = await _client.SendAsync(request).ConfigureAwait(false);
string returnString = await response.Content.ReadAsStringAsync();
return returnString;
I'm not using any waits or accessing .Result, as I've seen many people try that don't understand async operations.
I've seen older posts (circa 2013) where the wrong HttpClient is used. Is this still an issue in current releases? I've also tried changing the HttpClient implementation in the iOS project settings, to no avail.
Thanks in advance!
The issue was an invalid Deployment Target - It was set to "80" instead of "8.0
In come cases, the build server does not communicate this invalidity back to your machine - hence why it took so long to notice it!
This may well be a duplicate question, but no answer from an existing question has solved my problem.
I have a WebAPI end point running on my dev machine. I've configured it to run on
.UseUrls("http://localhost:57971", "http://10.0.2.2:57971", "http://192.168.44.1:57971", "http://192.168.1.48:57971", "http://*:57971")
where:
192.168.44.1 is Desktop Adapter #2 on the emulator Networks settings tab
10.0.2.2 is the special address for the Android emulator, as set out in Google's doco (possibly not relevant to Xamarin) and
192.168.1.48 is my local IP address for my dev machine.
I have created a firewall rule permitting connections on TCP port 57971.
I researched this pretty heavily and heeded instructions such as those set out here http://briannoyesblog.azurewebsites.net/2016/03/06/calling-localhost-web-apis-from-visual-studio-android-emulator/
I'm kinda out of ideas. The annoying thing is, it fails silently. There is no exception and the output just basically shows the different threads exiting with code 0. And the application keeps running i.e. the debugging session is not returning the IDE to a "code entry" state. This may suggest that something else its at play here.
The code looks pretty innocuous to me:
protected async Task<T> GetAsync<T>(string url)
where T : new()
{
HttpClient httpClient = CreateHttpClient();
T result;
try
{
var response = await httpClient.GetStringAsync(url);
result = await Task.Run(() => JsonConvert.DeserializeObject<T>(response));
}
catch
{
result = new T();
}
return result;
}
I'm using Visual Studio 2015.
I'm using the Visual Studio emulator https://www.visualstudio.com/vs/msft-android-emulator/
Any idea how I can get wheels on the ground on this thing?
Is there a way to Ping my machine from the emulator?
Thanks
I got this working by using 169.254.80.80 i.e. I added it to the list of urls which the API serves and called that ip address from the Xamarin app.
So, in Program.cs became simple:
.UseUrls("http://localhost:57971", "http://169.254.80.80:57971")
I also had to add it to the bindings element ApplicationConfig file in the hidden .vs folder of the ASP.NET API solution. Not sure why it had to be 169.254.80.80, as that was Desktop Adapter #4.
That got it working.
I'm trying to make a simple web api call using HttpClient in an iOS build. When setting the client.BaseAddress, the BaseAddress always ends up null. I can't find what could possibly be wrong.
using System.Net.Http;
....
private const string BaseApiUrl = "http://localhost:55904/";
static HttpClient client = new HttpClient();
client.BaseAddress = new Uri(BaseApiUrl);
// client.BaseAddress is still null
I downloaded a sample non-Xamarin project and the same code works fine.
Any ideas?
Update
As I continue messing with this I figured I would try some of the other platforms. UWP seems to work fine. I was going to test Android but all of a sudden, I have a bunch of "The name 'InitializeComponent' does not exist in the current context" errors.
I'm new to Xamarin but not to VS or C#.
Update
I was just thinking, does iOS need to request any special permission for internet access? If so, where would that be set?
Just in case anyone else comes across this problem, I found the cause. It turns out that the iOS project didn't include a reference to System.Net.Http. Once I added the reference, everything worked fine.
I am writing an android app that makes requests using the HttpClient interface from the Apache Commons project (supplied with both versions of android).
The problem occurs in the following code listing:
try {
URI uri = URIUtils.createURI(SCHEME, host, DEFAULT_PORT, QUERY,
URLEncodedUtils.format(qparams, ENCODING), EMPTY_FRAGMENT);
HttpUriRequest request = new HttpGet(uri);
response = client.execute(request);
} catch (Exception e) {
throw new CheckedSecurityException("Could not execute request", e);
}
Android 2.2 does this just fine (API level 8) but when I run this on Android 2.1-update1 (API level 7) it "hangs" at client.execute(request). What am I doing wrong?
Okay, I figured this out myself.
Part of the problem was that I had to use 10.0.2.2 from the emulator and I wrote a class that detects the emulator using the model. the string google_sdk worked fine for me before. But yesterday I updated my SDK and apparently they changed it to just sdk so the class wasn't detecting the device as an emulator before and was using the wrong IP address.
Status: Solved!