First of all, I would like to say, I'm quite new to C#.
I'm trying to create a POST request which sends some data to a PHP file somewhere on a different server.
Now, after the request is send I would like to see the response, as I'm sending back a JSON string from the server as a success message.
When I use the following code:
public MainPage()
{
this.InitializeComponent();
Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().SetDesiredBoundsMode(Windows.UI.ViewManagement.ApplicationViewBoundsMode.UseCoreWindow);
responseBlockTxt.Text = start();
}
public string start()
{
var response = sendRequest();
System.Diagnostics.Debug.WriteLine(response);
return "";
}
public async Task<string> sendRequest()
{
using (var client = new HttpClient())
{
var values = new Dictionary<string, string>
{
{ "vote", "true" },
{ "slug", "the-slug" }
};
var content = new FormUrlEncodedContent(values);
var response = await client.PostAsync("URL/api.php", content);
var responseString = await response.Content.ReadAsStringAsync();
return responseString;
}
}
The output is:
System.Threading.Tasks.Task`1[System.String]
So, how would I see all the results from this?
Go Async all the way. Avoid blocking calls when calling async methods. async void is allowed in event handlers so update page to perform the call on load event
Read up on Async/Await - Best Practices in Asynchronous Programming
And then update your code accordingly
public MainPage() {
this.InitializeComponent();
Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().SetDesiredBoundsMode(Windows.UI.ViewManagement.ApplicationViewBoundsMode.UseCoreWindow);
this.Loaded += OnLoaded;
}
public async void OnLoaded(object sender, RoutedEventArgs e) {
responseBlockTxt.Text = await start();
}
public async Task<string> start() {
var response = await sendRequest();
System.Diagnostics.Debug.WriteLine(response);
return response;
}
private static HttpClient client = new HttpClient();
public async Task<string> sendRequest() {
var values = new Dictionary<string, string> {
{ "vote", "true" },
{ "slug", "the-slug" }
};
var content = new FormUrlEncodedContent(values);
using(var response = await client.PostAsync("URL/api.php", content)) {
var responseString = await response.Content.ReadAsStringAsync();
return responseString;
}
}
I Guess
public string start()
{
var response = sendRequest();
Task<String> t = sendRequest();
System.Diagnostics.Debug.WriteLine(t.Result);
return "";
}
public async Task<string> sendRequest()
{
using (var client = new HttpClient())
{
var values = new Dictionary<string, string>
{
{ "vote", "true" },
{ "slug", "the-slug" }
};
var content = new FormUrlEncodedContent(values);
var response = await client.PostAsync("URL/api.php", content);
var responseString = await response.Content.ReadAsStringAsync();
return responseString;
}
}
The problem is in the start method, the SendRequest method returns a Task<string> and that's what you get on your response variable. Since you are attempting to run an async method synchronously you have to do some extra stuff, try this:
public string start()
{
var response = sendRequest().ConfigureAwait(true)
.GetAwaiter()
.GetResult();
System.Diagnostics.Debug.WriteLine(response);
return "";
}
That get the actual result inside your awaitable Task<string>. If you want to find some more info on this take a look at this question
public string start()
{
var response = sendRequest().ConfigureAwait(true)
.GetAwaiter()
.GetResult();
System.Diagnostics.Debug.WriteLine(response);
return "";
}
I have Tried this. It is working perfectly.
Related
I am bit frustrated now what's wrong with my code, and I hope you guys can help me with it, so here are the things I have tried.
so I tried making the HttpClient static, and I tried using the IHttpClientFactory.CreateClient() and I even added this on my .csproj
<ServerGarbageCollection>false</ServerGarbageCollection>
Here is the sample code that I have been doing
public class TestController : BaseController
{
private static HttpClient _httpClient = new();
public TestController()
{
}
[HttpGet("bills")]
public async Task<IActionResult> GetBillsPresentment([FromQuery] GetBillPresentmentQuery query)
{
if (!query.AccountNumber.Contains("-"))
query.AccountNumber = FormatAccountNumber(query.AccountNumber);
var billDetails = await GetBillDetail(query.AccountNumber);
if (billDetails == null)
throw new ProviderProcessException(ProviderErrorCode.INVALID_ACCOUNT_NUMBER);
return Ok(new BillPresentmentVm
{
User = new CustomerDto
{
CustomerName = billDetails.Name
},
Billing = new BillingDto
{
AccountNumber = query.AccountNumber,
DueDate = DateTime.Parse(billDetails.LastReadDate).AddMonths(1),
Outstanding = !string.IsNullOrEmpty(billDetails.Arrears) ? decimal.Parse(billDetails.Arrears) : null
}
});
}
private async Task<ResponseModel> GetBillDetail(string accountNumber)
{
try
{
var payload = new { accno = accountNumber };
string json = JsonConvert.SerializeObject(payload);
var buffer = System.Text.Encoding.UTF8.GetBytes(json);
using var byteContent = new ByteArrayContent(buffer);
byteContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
var response = await _httpClient.PostAsync("https://test.com", byteContent);
if (!response.IsSuccessStatusCode)
throw new ProviderProcessException(ProviderErrorCode.BILLING_CYCLE_UNAVAILABLE);
var result = await response.Content.ReadAsStringAsync();
if (result == "Accno not found!") return null;
var data = JsonConvert.DeserializeObject<ResponseModel>(result);
return data;
}
catch (Exception)
{
throw new ProviderProcessException(ProviderErrorCode.BILLING_CYCLE_UNAVAILABLE);
}
}
private static string FormatAccountNumber(string accountNumber)
{
return string.Format("{0:#######-########}", Convert.ToInt64(accountNumber));
}
}
And here's the docker memory usage
The memory usage keeps increasing after a request. Can someone explains me why it is not decreasing?
Thank you very much in advance
I solve this issue using IHttpClientFactory instead of HttpClient.
https://learn.microsoft.com/en-us/dotnet/architecture/microservices/implement-resilient-applications/use-httpclientfactory-to-implement-resilient-http-requests
I use some thing like this and it works fine on large amount of requests per second and it use memory in normal way .
namespace BehsaLoyalty.ApiClient
{
public class ApiRepo : IApiRepo
{
private readonly IHttpClientFactory _HttpClientFactory;
public ApiRepo (IHttpClientFactory httpClientFactory)
{
_HttpClientFactory = httpClientFactory;
}
public async Task<ResponseModel> PostMyObject(Myobject model, CancellationToken cancellationToken)
{
HttpClient httpClient = _HttpClientFactory.CreateClient("ApiDestinationURI");
using HttpRequestMessage request = new(HttpMethod.Post, "/blah/blah");
request.Content = new StringContent(JsonSerializer.Serialize(model));
request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
HttpResponseMessage response = await httpClient.SendAsync(request, HttpCompletionOption.ResponseContentRead, cancellationToken);
response.EnsureSuccessStatusCode();
string createdContent = await response.Content.ReadAsStringAsync();
ResponseModel ResponseReturn = JsonSerializer.Deserialize<ResponseModel>(createdContent);
return ResponseReturn;
}
}
}
I want to connect to my Web api with these code
but when debugger arrived on
var response = await client.GetAsync(url);
skip without any error,
UPDATE
it's mean:
I set breakpoint and when debugger arrive on that line after that don't catch the next line and exit from this block and jump to caller method
public class Constants
{
public const string BaseUrl = "https://localhost:44301/";
}
2:
public static class GeneralUrl
{
public static string ComapnyNameUrl()
{
return string.Format(Constants.BaseUrl);
}
}
3: change to 3.1
public async static Task<List<CompanyName>> GetCompanyNamesAsync()
{
List<CompanyName> companyNameList = new List<CompanyName>();
string url = GeneralUrl.ComapnyNameUrl() + "api/CompanyName";
using (HttpClient client = new HttpClient())
{
var response = await client.GetAsync(url);
if (response.IsSuccessStatusCode)
{
string content =await response.Content.ReadAsStringAsync();
companyNameList = JsonConvert.DeserializeObject<List<CompanyName>>(content);
}
}
return companyNameList;
}
UPDATE 2
3.1:
I change above code to this but the problen exist
Update
public class CompanyNameService
{
private static HttpClient client = new HttpClient();
public async static Task<List<CompanyName>> GetCompanyNamesAsync()
{
List<CompanyName> companyNameList = new List<CompanyName>();
string url = GeneralUrl.ComapnyNameUrl() + "api/Companyname";
var response = await client.GetAsync(url);
if (response.IsSuccessStatusCode)
{
string content =await response.Content.ReadAsStringAsync();
companyNameList = JsonConvert.DeserializeObject<List<CompanyName>>(content);
}
return companyNameList;
}
}
also my startup.cs in my web api is
services.AddControllers().AddJsonOptions(o =>
{
o.JsonSerializerOptions.ReferenceHandler = ReferenceHandler.Preserve;
o.JsonSerializerOptions.MaxDepth = 0;
});
services.AddControllers().AddNewtonsoftJson(options =>
options.SerializerSettings.ReferenceLoopHandling =
Newtonsoft.Json.ReferenceLoopHandling.Ignore);
END OF UPDATE 2
and final for calling them is=>
4:
protected override async void OnAppearing()
{
base.OnAppearing();
var companyName = await CompanyNameService.GetCompanyNamesAsync();
}
I think that it was for async method what is my mistake??
UPDATE
In debug mode in output windows I have this message
02-10 13:04:21.568 I/Choreographer( 790): Skipped 428 frames! The application may be doing too much work on its main thread.
02-10 13:04:21.642 I/OpenGLRenderer( 790): Davey! duration=7213ms; Flags=0, IntendedVsync=51372290598463, Vsync=51379423931511, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=51379430268200, AnimationStart=51379430347200, PerformTraversalsStart=51379430673700, DrawStart=51379441519600, SyncQueued=51379446948700, SyncStart=51379447122900, IssueDrawCommandsStart=51379447270300, SwapBuffers=51379483411800, FrameCompleted=51379504170100, DequeueBufferDuration=409000, QueueBufferDuration=612000,
UPDATE 3:
As I try use local address, after more than 5 min got a message in out put window that "the operation in canceled" and catch the exception with the same message.
Try this:
protected async override void OnAppearing()
{
base.OnAppearing();
var companyName = await GetCompanyNamesAsync();
}
public async static Task<List<CompanyName>> GetCompanyNamesAsync()
{
List<CompanyName> companyNameList = new List<CompanyName>();
string url = GeneralUrl.ComapnyNameUrl() + "api/Companyname";
using (HttpClient client = new HttpClient())
{
var response = await client.GetStringAsync(url);
companyNameList = JsonConvert.DeserializeObject<List<CompanyName>>(response);
}
return companyNameList;
}
I have my Web Api on a production server online and working well in postman and in Xamarin forms so far until I needed to do a Get Request and does not return any data. Infact it stops at the GetAsStringAsync line and does not continue. Instead, it jumps out of the method and then nothing more.
Does any one know what the problem could be? I have checked and made sure my Internet is working and the Uri too.
This is where I am doing my Get in Xamarin forms:
public async Task<List<OfferModel>> AllOffers()
{
var httpclient = new HttpClient();
httpclient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", Settings.AccessToken);
//it does not continue after this line, it jumps out of the method instead
var response = await httpclient.GetStringAsync(UrlConstants.offerurl);
var data =JsonConvert.DeserializeObject<List<OfferModel(response);
return data;
}
Solution 1
Can you try access task via awaiter it may be wait until result when responded
public class HttpHelperService
{
public async Task<List<OfferModel>> AllOffers()
{
List<OfferModel> result;
string responseBody;
using (HttpClient client = new HttpClient())
{
try
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", Settings.AccessToken);
HttpResponseMessage response = client.GetStringAsync(new Uri(UrlConstants.offerurl)).GetAwaiter().GetResult();
result = JsonConvert.DeserializeObject<List<OfferModel>>(response);
}
catch (Exception ex)
{
result = null;
}
return result;
}
}
}
Solution 2
public class MyPage : ContentPage
{
//Here is your page constructor
public MyPage()
{
GetServices(); //--> call here without awaiter
}
}
//Here is your awaiter method
private async void GetServices()
{
LoadingPopupService.Show();
var result = await HttpService.AllOffers();
LoadingPopupService.Hide();
}
//Here is your service.
public async Task<List<OfferModel>> AllOffers()
{
var httpclient = new HttpClient();
httpclient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", Settings.AccessToken);
var response = await httpclient.GetStringAsync(UrlConstants.offerurl);
var data =JsonConvert.DeserializeObject<List<OfferModel(response);
return data;
}
I have the code below in a console app. The LookUpUser method gets called and PostAsJsonAsync gets called but breakpoints in the response checking don't get hit afterwards. What am I doing incorrectly in this implementation?
static void Main(string[] args)
{
TestUseCase().GetAwaiter().GetResult();
}
private static async Task TestUseCase()
{
await GetUserGuids();
}
private static async Task GetUserGuids()
{
var userGuids = new List<Guid>();
userGuids.Add(Guid.Parse("7b5cf09c-196c-4e0b-a0e2-0683e4f11213"));
userGuids.Add(Guid.Parse("3a636154-b7fc-4d96-9cd1-d806119ff79f"));
userGuids.ForEach(async x => await LookUpUser(x));
}
private static async Task LookUpUser(Guid adUserGuid)
{
var client = new HttpClientManager().GetHttpClient();
var response = await client.PostAsJsonAsync("api/v1/users/search", new { ADUserGuid = adUserGuid });
if (response.IsSuccessStatusCode)
{
var groups = await response.Content.ReadAsAsync<List<User>>();
}
else //not 200
{
var message = await response.Content.ReadAsStringAsync();
}
}
userGuids.ForEach(async x => await LookUpUser(x));
The delegate in the ForEach is basically a async void (fire and forget)
Consider selecting a collection of Task and then use Task.WhenAll
private static async Task GetUserGuids() {
var userGuids = new List<Guid>();
userGuids.Add(Guid.Parse("7b5cf09c-196c-4e0b-a0e2-0683e4f11213"));
userGuids.Add(Guid.Parse("3a636154-b7fc-4d96-9cd1-d806119ff79f"));
var tasks = userGuids.Select(x => LookUpUser(x)).ToArray();
await Task.WhenAll(tasks);
}
Also assuming HttpClientManager.GetHttpClient() returns a HttpClient there is no need to create multiple instances. on static client should do
static HttpClient client = new HttpClientManager().GetHttpClient();
private static async Task LookUpUser(Guid adUserGuid) {
var response = await client.PostAsJsonAsync("api/v1/users/search", new { ADUserGuid = adUserGuid });
if (response.IsSuccessStatusCode) {
var groups = await response.Content.ReadAsAsync<List<User>>();
} else {
//not 200
var message = await response.Content.ReadAsStringAsync();
}
}
I got it to work by changing the ForEach to:
foreach (var guid in userGuids)
{
await LookUpUserInSecurityApi(guid);
}
I need to load data on a XAML page in a windows 10 UWP application. For that I wrote code to call the web service in async task function, and I call this in page constructor. Could you please tell best way to do this? Following is my code.
public sealed partial class MyDownloads : Page
{
string result;
public MyDownloads()
{
this.InitializeComponent();
GetDownloads().Wait();
string jsonstring = result;
//code for binding follows
}
private async Task GetDownloads()
{
JsonObject jsonObject = new JsonObject
{
{"StudentID", JsonValue.CreateStringValue(user.Student_Id.ToString()) },
};
string ServiceURI = "http://m.xxx.com/xxxx.svc/GetDownloadedNotes";
HttpClient httpClient = new HttpClient();
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, ServiceURI);
request.Content = new StringContent(jsonObject.ToString(), Encoding.UTF8, "application/json");
HttpResponseMessage response = await httpClient.SendAsync(request);
string returnString = await response.Content.ReadAsStringAsync();
result = returnString;
}
}
Instead that you need use OnNavigatedTo
because, GetDownloads().Wait() bad practice. You block UI Thread until the end of execution
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
}
protected override async void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
var result = await GetDownloadsAsync();
string jsonstring = result;
}
private async Task<string> GetDownloadsAsync()
{
JsonObject jsonObject = new JsonObject
{
{"StudentID", JsonValue.CreateStringValue(user.Student_Id.ToString()) },
};
string ServiceURI = "http://m.xxx.com/xxxx.svc/GetDownloadedNotes";
HttpClient httpClient = new HttpClient();
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, ServiceURI);
request.Content = new StringContent(jsonObject.ToString(), Encoding.UTF8, "application/json");
HttpResponseMessage response = await httpClient.SendAsync(request);
string returnString = await response.Content.ReadAsStringAsync();
return returnString;
}
}