Unable to fetch data in Xamarin.Forms project. I have tried with the following code and is getting NameResolutionFailure error.
private const string BaseUrl = "http://intilaqemployees.azurewebsites.net/api/employeesapi";
public async Task<List<Employee>> GetEmployeesAsync()
{
var httpClient = new HttpClient();
try
{
var jsonResponse = await httpClient.GetStringAsync(BaseUrl).ConfigureAwait(false);
//The following line never gets executed
var employeesList = JsonConvert.DeserializeObject<List<Employee>>(jsonResponse);
return employeesList;
}
catch (AggregateException exception) { }
catch (Exception ex)
{
}
return null;
}
This is what I have tried so far
Have enable INTERNET in android manifest
Translating the host name to ip
Tried to set host directly by setting client.DefaultRequestHeaders.Host = "intilaqemployees.azurewebsites.net";
Putting the wifi off in emulator
Please note: Android emulator does not have any internet connectivity.
My problem solved by this code:
var client = new HttpClient {
BaseAddress = new Uri("http://1.2.3.4"),
DefaultRequestHeaders = { Host = "example.com" }
};
Related
I am working on a Xamarin App where I am facing an issue.
Case 1:
Mode: Debug
Error: System.NullReferenceException: 'Object reference not set to an instance of an object'
Explanation:
No value is being set and passed to ViewModel, Controller.
Even I tried setting static values to variables and parameters.
LoginModel logtest = new LoginModel();
logtest.Username = "Test#user.com"; //uName;
logtest.Password = "2342534"; //pWord;
Tried solution:
In the beginning, I tried many different solutions nothing worked.
Then I create a new project and moved all the code to the new project, then it started working.
Case 2:
Mode: release
Now the same issue I am getting in release mode.
No value is being set and passed to ViewModels and Controller.
I have already tried moving code to a new project.
How can I resolve this? I am not sure is this a Visual studio issue or Xamarin issue or Apple.
I have tried updating Visual Studio enterprise 2019 and Xcode on Mac.
Deleted and recreated Provisioning Profiles and Signing Identities.
Code From LoginPage.xaml.cs
private async void LoginButtonClicked(object sender, EventArgs e)
{
await ((LoginViewModel)BindingContext).Login();
}
protected async override void OnAppearing()
{
//App.Current.MainPage = new Navigation(new DashboardPage());
//load the login page
Device.BeginInvokeOnMainThread(() =>
{
try
{
((LoginViewModel)BindingContext).IsLoading = false;
((LoginViewModel)BindingContext).RememberMe = DeviceStorage.RememberMe;
if (DeviceStorage.RememberMe == true)
{
((LoginViewModel)BindingContext).UserName = "Test#user.ca"; //Trying set static values here
((LoginViewModel)BindingContext).Password = "password"; //Trying set static values here
}
//RememberMeToggle.Toggled += switcher_Toggled;
((LoginViewModel)BindingContext).Load();
}
catch (Exception ex)
{
//logger.Error(App.LogPrefix() + "Error opening Navigation Page: " + ex.Message);
Console.WriteLine(App.LogPrefix() + "Error opening Load(): " + ex.Message);
}
});
}
Code from LoginViewModel.cs
public async Task Login()
{
IsLoading = true;
await TokenController.GetAuthorizationToken(UserName, Password);
}
Code from TokenController.cs
public static async Task GetAuthorizationToken(string uName, string pWord)
{
bool tokenReturned = false;
string tokenGetResponse = string.Empty;
// Have tried setting them static values as well
LoginModel logtest = new LoginModel();
logtest.Username = uName;
logtest.Password = pWord;
logtest.AppType = Constants.AppDetails.APP_CODE;
logtest.SystemCode = Constants.AppDetails.SYSTEM_CODE;
logtest.Push.PushSystem = PushAddressModel.PushSystemCode.FireBase;
logtest.Push.Address = ((App)App.Current).PushNotificationToken;
logtest.Push.AppCode = Constants.AppDetails.APP_CODE;
string uri = URI.message_Chat_Endpoint;
(tokenReturned, tokenGetResponse) = await ApiFunctions.Post(logtest, URI.token_Endpoint, false);
if (tokenReturned)
{
try
{
//deserialize the return object
TokenModel token = JsonConvert.DeserializeObject<TokenModel>(tokenGetResponse);
((App)App.Current).token = token;
}
catch (Exception ex)
{
Console.WriteLine("Error: " + ex.Message);
//logger.Error(App.LogPrefix() + "Error: " + ex.Message);
}
Console.WriteLine("Profile Token loaded: " + ((App)App.Current).token.access_token);
}
else
{
Console.WriteLine("Error: Error loading profile token ");
//logger.Error(App.LogPrefix() + "Error loading profile token");
}
}
I have an ASP.NET Core 3.0 Web API endpoint that I have set up to allow me to post large audio files. I have followed the following directions from MS docs to set up the endpoint.
https://learn.microsoft.com/en-us/aspnet/core/mvc/models/file-uploads?view=aspnetcore-3.0#kestrel-maximum-request-body-size
When an audio file is uploaded to the endpoint, it is streamed to an Azure Blob Storage container.
My code works as expected locally.
When I push it to my production server in Azure App Service on Linux, the code does not work and errors with
Unhandled exception in request pipeline: System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Request body too large.
Per advice from the above article, I have configured incrementally updated Kesterl with the following:
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseKestrel((ctx, options) =>
{
var config = ctx.Configuration;
options.Limits.MaxRequestBodySize = 6000000000;
options.Limits.MinRequestBodyDataRate =
new MinDataRate(bytesPerSecond: 100,
gracePeriod: TimeSpan.FromSeconds(10));
options.Limits.MinResponseDataRate =
new MinDataRate(bytesPerSecond: 100,
gracePeriod: TimeSpan.FromSeconds(10));
options.Limits.RequestHeadersTimeout =
TimeSpan.FromMinutes(2);
}).UseStartup<Startup>();
Also configured FormOptions to accept files up to 6000000000
services.Configure<FormOptions>(options =>
{
options.MultipartBodyLengthLimit = 6000000000;
});
And also set up the API controller with the following attributes, per advice from the article
[HttpPost("audio", Name="UploadAudio")]
[DisableFormValueModelBinding]
[GenerateAntiforgeryTokenCookie]
[RequestSizeLimit(6000000000)]
[RequestFormLimits(MultipartBodyLengthLimit = 6000000000)]
Finally, here is the action itself. This giant block of code is not indicative of how I want the code to be written but I have merged it into one method as part of the debugging exercise.
public async Task<IActionResult> Audio()
{
if (!MultipartRequestHelper.IsMultipartContentType(Request.ContentType))
{
throw new ArgumentException("The media file could not be processed.");
}
string mediaId = string.Empty;
string instructorId = string.Empty;
try
{
// process file first
KeyValueAccumulator formAccumulator = new KeyValueAccumulator();
var streamedFileContent = new byte[0];
var boundary = MultipartRequestHelper.GetBoundary(
MediaTypeHeaderValue.Parse(Request.ContentType),
_defaultFormOptions.MultipartBoundaryLengthLimit
);
var reader = new MultipartReader(boundary, Request.Body);
var section = await reader.ReadNextSectionAsync();
while (section != null)
{
var hasContentDispositionHeader = ContentDispositionHeaderValue.TryParse(
section.ContentDisposition, out var contentDisposition);
if (hasContentDispositionHeader)
{
if (MultipartRequestHelper
.HasFileContentDisposition(contentDisposition))
{
streamedFileContent =
await FileHelpers.ProcessStreamedFile(section, contentDisposition,
_permittedExtensions, _fileSizeLimit);
}
else if (MultipartRequestHelper
.HasFormDataContentDisposition(contentDisposition))
{
var key = HeaderUtilities.RemoveQuotes(contentDisposition.Name).Value;
var encoding = FileHelpers.GetEncoding(section);
if (encoding == null)
{
return BadRequest($"The request could not be processed: Bad Encoding");
}
using (var streamReader = new StreamReader(
section.Body,
encoding,
detectEncodingFromByteOrderMarks: true,
bufferSize: 1024,
leaveOpen: true))
{
// The value length limit is enforced by
// MultipartBodyLengthLimit
var value = await streamReader.ReadToEndAsync();
if (string.Equals(value, "undefined",
StringComparison.OrdinalIgnoreCase))
{
value = string.Empty;
}
formAccumulator.Append(key, value);
if (formAccumulator.ValueCount >
_defaultFormOptions.ValueCountLimit)
{
return BadRequest($"The request could not be processed: Key Count limit exceeded.");
}
}
}
}
// Drain any remaining section body that hasn't been consumed and
// read the headers for the next section.
section = await reader.ReadNextSectionAsync();
}
var form = formAccumulator;
var file = streamedFileContent;
var results = form.GetResults();
instructorId = results["instructorId"];
string title = results["title"];
string firstName = results["firstName"];
string lastName = results["lastName"];
string durationInMinutes = results["durationInMinutes"];
//mediaId = await AddInstructorAudioMedia(instructorId, firstName, lastName, title, Convert.ToInt32(duration), DateTime.UtcNow, DateTime.UtcNow, file);
string fileExtension = "m4a";
// Generate Container Name - InstructorSpecific
string containerName = $"{firstName[0].ToString().ToLower()}{lastName.ToLower()}-{instructorId}";
string contentType = "audio/mp4";
FileType fileType = FileType.audio;
string authorName = $"{firstName} {lastName}";
string authorShortName = $"{firstName[0]}{lastName}";
string description = $"{authorShortName} - {title}";
long duration = (Convert.ToInt32(durationInMinutes) * 60000);
// Generate new filename
string fileName = $"{firstName[0].ToString().ToLower()}{lastName.ToLower()}-{Guid.NewGuid()}";
DateTime recordingDate = DateTime.UtcNow;
DateTime uploadDate = DateTime.UtcNow;
long blobSize = long.MinValue;
try
{
// Update file properties in storage
Dictionary<string, string> fileProperties = new Dictionary<string, string>();
fileProperties.Add("ContentType", contentType);
// update file metadata in storage
Dictionary<string, string> metadata = new Dictionary<string, string>();
metadata.Add("author", authorShortName);
metadata.Add("tite", title);
metadata.Add("description", description);
metadata.Add("duration", duration.ToString());
metadata.Add("recordingDate", recordingDate.ToString());
metadata.Add("uploadDate", uploadDate.ToString());
var fileNameWExt = $"{fileName}.{fileExtension}";
var blobContainer = await _cloudStorageService.CreateBlob(containerName, fileNameWExt, "audio");
try
{
MemoryStream fileContent = new MemoryStream(streamedFileContent);
fileContent.Position = 0;
using (fileContent)
{
await blobContainer.UploadFromStreamAsync(fileContent);
}
}
catch (StorageException e)
{
if (e.RequestInformation.HttpStatusCode == 403)
{
return BadRequest(e.Message);
}
else
{
return BadRequest(e.Message);
}
}
try
{
foreach (var key in metadata.Keys.ToList())
{
blobContainer.Metadata.Add(key, metadata[key]);
}
await blobContainer.SetMetadataAsync();
}
catch (StorageException e)
{
return BadRequest(e.Message);
}
blobSize = await StorageUtils.GetBlobSize(blobContainer);
}
catch (StorageException e)
{
return BadRequest(e.Message);
}
Media media = Media.Create(string.Empty, instructorId, authorName, fileName, fileType, fileExtension, recordingDate, uploadDate, ContentDetails.Create(title, description, duration, blobSize, 0, new List<string>()), StateDetails.Create(StatusType.STAGED, DateTime.MinValue, DateTime.UtcNow, DateTime.MaxValue), Manifest.Create(new Dictionary<string, string>()));
// upload to MongoDB
if (media != null)
{
var mapper = new Mapper(_mapperConfiguration);
var dao = mapper.Map<ContentDAO>(media);
try
{
await _db.Content.InsertOneAsync(dao);
}
catch (Exception)
{
mediaId = string.Empty;
}
mediaId = dao.Id.ToString();
}
else
{
// metadata wasn't stored, remove blob
await _cloudStorageService.DeleteBlob(containerName, fileName, "audio");
return BadRequest($"An issue occurred during media upload: rolling back storage change");
}
if (string.IsNullOrEmpty(mediaId))
{
return BadRequest($"Could not add instructor media");
}
}
catch (Exception ex)
{
return BadRequest(ex.Message);
}
var result = new { MediaId = mediaId, InstructorId = instructorId };
return Ok(result);
}
I reiterate, this all works great locally. I do not run it in IISExpress, I run it as a console app.
I submit large audio files via my SPA app and Postman and it works perfectly.
I am deploying this code to an Azure App Service on Linux (as a Basic B1).
Since the code works in my local development environment, I am at a loss of what my next steps are. I have refactored this code a few times but I suspect that it's environment related.
I cannot find anywhere that mentions that the level of App Service Plan is the culprit so before I go out spending more money I wanted to see if anyone here had encountered this challenge and could provide advice.
UPDATE: I attempted upgrading to a Production App Service Plan to see if there was an undocumented gate for incoming traffic. Upgrading didn't work either.
Thanks in advance.
-A
Currently, as of 11/2019, there is a limitation with the Azure App Service for Linux. It's CORS functionality is enabled by default and cannot be disabled AND it has a file size limitation that doesn't appear to get overridden by any of the published Kestrel configurations. The solution is to move the Web API app to a Azure App Service for Windows and it works as expected.
I am sure there is some way to get around it if you know the magic combination of configurations, server settings, and CLI commands but I need to move on with development.
have the following which works on Win10 phone in a pcl.
But i cannot get the same code to return OK on samsung s7 with android 7.0
project is xamarin forms.
nuget for system.net.http is 2.2.29.
I've include the same nuget in my UWP for the win10 phone and android projects.
i've also changed the user to include be "domain\user", "domain#user", "user#domain"
var httpClientHandler = new System.Net.Http.HttpClientHandler()
{
Credentials = credentials.GetCredential(new Uri(location), "NTLM")
};
I've tried and alternative to setting the httpClientHandler.Credentials.
var credentials = new NetworkCredentials("user", "pass", "domain");
var location = "http://apps.mysite.com/api#/doit";
var httpClientHandler = new HttpClientHandler{
Credentials = credentials
}
using (var httpClient = new HttpClient(httpClientHandler, true))
{
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
httpClient.DefaultRequestHeaders.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
try
{
var httpResponseMessage = await httpClient.GetAsync(location);
if (httpResponseMessage.StatusCode != System.Net.HttpStatusCode.OK)
{
//handle error
}
else
{
//do something
}
}
catch (Exception)
{}
finally
{}
}
another strange thing. when i run this on android, the code hits the await httpclient.getasync(location);
and the immediately jumps to the finally.
I hava a simple form with username & password Entry Fields, plus an OK button.
all three controls are bound to a viewmodel. the OK button via an ICommand.
this code and the view live in the PCL. which has a reference to Microsoft.Net.Http.
I have Android and Universal Windows Xamarin forms builds that consume the PCL.
Android Properties. Default httpClient, SSL/TLS Default. supported arch armeabi, armeabi-v7a;x86
Android Manifest: Camera, flashlight and internet
private bool calcEnabled = false;
private ICommand okCommand;
private string message = string.Empty;
private string validatingMessage = "Validating!";
private string unauthorizedMessage = "Invalid Credentials!";
private string authenticatedMessage = "Validated";
private bool validating = false;
public ICommand OkCommand => okCommand ?? (okCommand = new Command<object>((o) => clicked(o), (o) => CalcEnabled));
protected async void clicked(object state)
{
try
{
Validating = true;
Message = validatingMessage;
var credentials = new
System.Net.NetworkCredential(Helpers.Settings.UserName, Helpers.Settings.Password, "www.domain.com");
var location = "http://apps.wwwoodproducts.com/wwlocator#/information";
var httpClientHandler = new System.Net.Http.HttpClientHandler()
{
Credentials = credentials.GetCredential(new Uri(location), "NTLM") };
using (var httpClient = new System.Net.Http.HttpClient(httpClientHandler))
{
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
httpClient.DefaultRequestHeaders.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
try
{
var httpResponseMessage = await
httpClient.GetAsync(location);
if (httpResponseMessage.StatusCode != System.Net.HttpStatusCode.OK)
{
Message = unauthorizedMessage;
}
else
{
Message = authenticatedMessage;
Messenger.Default.Send<bool>(true);
}
}
catch (Exception)
{
Message = unauthorizedMessage;
}
finally
{
Validating = false;
}
}
}
catch (Exception)
{
throw;
}
}
I am using Microsoft Graph SDK to upload file in chunks in OneDrive. I am using below code to upload the file:
try
{
GraphServiceClient graphClient = this.GetGraphServiceClient(accessToken);
string fileName = Path.GetFileName(srcFilePath);
using (var fileContentStream = System.IO.File.Open(srcFilePath, System.IO.FileMode.Open))
{
var uploadSession = await graphClient.Me.Drive.Root.ItemWithPath(fileName).CreateUploadSession().Request().PostAsync();
var maxChunkSize = 5 * 1024 * 1024;
var provider = new ChunkedUploadProvider(uploadSession, graphClient, fileContentStream, maxChunkSize);
var chunkRequests = provider.GetUploadChunkRequests();
var readBuffer = new byte[maxChunkSize];
var trackedExceptions = new List<Exception>();
Microsoft.Graph.DriveItem itemResult = null;
foreach (var request in chunkRequests)
{
var result = await provider.GetChunkRequestResponseAsync(request, readBuffer, trackedExceptions);
if (result.UploadSucceeded)
{
itemResult = result.ItemResponse;
}
}
}
}
catch (Microsoft.Graph.ServiceException e)
{
}
catch (Exception ex)
{
}
The above code works fine with normal file names. However, when I am trying to upload a file with name as Test#123.pdf, "Object reference not set to an object" exception is thrown at line var provider = new ChunkedUploadProvider(uploadSession, graphClient, fileContentStream, maxChunkSize); Please see below screenshot:
Is this a limitation of OneDrive SDK, or am I not passing the parameters correctly?
The # sign has a special meaning in a URL. Before you can use it, you'll need to URL Encode the file name: Test%23123.pdf.
I'm having some trouble getting uploaded files to save to S3. My first attempt was:
Result SaveFile(System.Web.HttpPostedFileBase file, string path)
{
//Keys are in web.config
var t = new Amazon.S3.Transfer.TransferUtility(Amazon.RegionEndpoint.USWest2);
try
{
t.Upload(new Amazon.S3.Transfer.TransferUtilityUploadRequest
{
BucketName = Bucket,
InputStream = file.InputStream,
Key = path
});
}
catch (Exception ex)
{
return Result.FailResult(ex.Message);
}
return Result.SuccessResult();
}
This throws an exception with the message: "The request signature we calculated does not match the signature you provided. Check your key and signing method." I also tried copying file.InputStream to a MemoryStream, then uploading that, with the same error.
If I set the InputStream to:
new FileStream(#"c:\folder\file.txt", FileMode.Open)
then the file uploads fine. Do I really need to save the file to disk before uploading it?
This is my working version first the upload method:
public bool Upload(string filePath, Stream inputStream, double contentLength, string contentType)
{
try
{
var request = new PutObjectRequest();
request.WithBucketName(_bucketName)
.WithCannedACL(S3CannedACL.PublicRead)
.WithKey(filePath).InputStream = inputStream;
request.AddHeaders(AmazonS3Util.CreateHeaderEntry("ContentType", contentType));
_amazonS3Client.PutObject(request);
}
catch (Exception exception)
{
// log or throw;
return false;
}
return true;
}
I just get the stream from HttpPostedFileBase.InputStream
(Note, this is on an older version of the Api, the WithBucketName syntax is no longer supported, but just set the properties directly)
Following the comment of shenku, for newer versions of SDK.
public bool Upload(string filePath, Stream inputStream, double contentLength, string contentType)
{
try
{
var request = new PutObjectRequest();
string _bucketName = "";
request.BucketName = _bucketName;
request.CannedACL = S3CannedACL.PublicRead;
request.InputStream = inputStream;
request.Key = filePath;
request.Headers.ContentType = contentType;
PutObjectResponse response = _amazonS3Client.PutObject(request);
return true;
}catch(Exception ex)
{
return false;
}
}