how to consume post api in xamarin forms - xamarin.forms

I consumed a get api by creating a base service like that:
public class BaseService<T> where T : class
{
private string baseUrl = "http://192.168.43.137:45455/api";
public IEnumerable<T> GetRequest(string uri)
{
baseUrl += uri;
var client = new RestClient(baseUrl);
var request = new RestRequest(Method.GET);
var response = client.Execute(request);
if (response.StatusCode == System.Net.HttpStatusCode.OK)
{
string json = response.Content;
return JsonConvert.DeserializeObject<IEnumerable<T>>(json);
}
return default;
}
and a userService like this:
public class UserServices {
public IEnumerable<User> GetUsers()
{
var requestService = new BaseService<User>();
return requestService.GetRequest("/Users");
}
It worked fine for the get but I don't know how to consume the post api like this

You can check the microsoft document "Consume a RESTful web service":
https://learn.microsoft.com/en-us/xamarin/xamarin-forms/data-cloud/web-services/rest
It shows you how to deal with the different kinds of requests, and there is a sample link in the bottom which you can refer to.

Related

Asp.net web api controller long querystring returns BadRequest

I have an Asp.net web api with one method that receive a crypted string with variable length, my problem is it string some times could take a length near 5000.
When that method receive a string under 1930 length it process everything ok, but for lengths over 1929 returns
404 Operation returned an invalid status code 'BadRequest'
I changed method GET to POST but problem persists.
I changed filter options on server to very very long limits, but problem persists
This is my controller:
public class LicencingManagerController : ApiController
{
[HttpPost]
[Route(nameof(SaveCustomer2))]
public string SaveCustomer2(string custInfo)
{
return $"ItsOk = {custInfo}";
}
}
Actually I made calls to controller using autogenerated c# client by AutoRest 2.0.483.
I tried hand building PostAsync Request using HttpClient but nothing works.
string custInfo = "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";
var pairs = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("custInfo", custInfo)
};
var content = new FormUrlEncodedContent(pairs);
var client = new HttpClient();
// call sync
var response = client.PostAsync($"{Modelos.Shared.HttpsServicesReference.Licencing}/LicencingAPI/SaveCustomer2", content).Result;
if (response.IsSuccessStatusCode)
{
}
What is the right way to process this controller call?
There is another approach to perform this ?
Create model to hold data
public class Customer {
public string CustumerInfo { get; set; }
}
Update API to expect model in body of request
public class LicencingManagerController : ApiController {
[HttpPost]
[Route(nameof(SaveCustomer2))]
public IHttpActionResult SaveCustomer2([FromBody]Customer model) {
if(!ModelState.IsValid)
return BadRequest(ModelState);
var custInfo = model.CustumerInfo;
return Ok($"ItsOk = {custInfo}");
}
}
Post content to API in body of the request like you did before
string custInfo = "H4sIAAAAAAAEAA...";
string url = $"{Modelos.Shared.HttpsServicesReference.Licencing}/LicencingAPI/SaveCustomer2";
var pairs = new List<KeyValuePair<string, string>> {
new KeyValuePair<string, string>("CustumerInfo", custInfo)
};
var content = new FormUrlEncodedContent(pairs);
var client = new HttpClient();
var response = await client.PostAsync(url, content);
if (response.IsSuccessStatusCode) {
}

.Net Core 2.0 - Get AAD access token to use with Microsoft Graph

When starting up a fresh .Net Core 2.0 project with Azure AD Authentication you get a working sample that can sign in to your tenant, great!
Now I want to get an access token for the signed in user and use that to work with Microsoft Graph API.
I am not finding any documentation on how to achieve this. I just want a simple way to get an access token and access the graph API, using the template created when you start a new .NET Core 2.0 project. From there I should be able to figure out the rest.
Very important that it works with the project that gets created when following the process where you select Work and school accounts for authentication when creating a new 2.0 MVC Core app in Visual Studio.
I wrote a blog article which shows just how to do that: ASP.NET Core 2.0 Azure AD Authentication
The TL;DR is that you should add a handler like this for when you receive an authorization code from AAD:
.AddOpenIdConnect(opts =>
{
Configuration.GetSection("Authentication").Bind(opts);
opts.Events = new OpenIdConnectEvents
{
OnAuthorizationCodeReceived = async ctx =>
{
var request = ctx.HttpContext.Request;
var currentUri = UriHelper.BuildAbsolute(request.Scheme, request.Host, request.PathBase, request.Path);
var credential = new ClientCredential(ctx.Options.ClientId, ctx.Options.ClientSecret);
var distributedCache = ctx.HttpContext.RequestServices.GetRequiredService<IDistributedCache>();
string userId = ctx.Principal.FindFirst("http://schemas.microsoft.com/identity/claims/objectidentifier").Value;
var cache = new AdalDistributedTokenCache(distributedCache, userId);
var authContext = new AuthenticationContext(ctx.Options.Authority, cache);
var result = await authContext.AcquireTokenByAuthorizationCodeAsync(
ctx.ProtocolMessage.Code, new Uri(currentUri), credential, ctx.Options.Resource);
ctx.HandleCodeRedemption(result.AccessToken, result.IdToken);
}
};
});
Here my context.Options.Resource is https://graph.microsoft.com (Microsoft Graph), which I'm binding from config along with other settings (client id etc.).
We redeem a token using ADAL, and store the resulting token in a token cache.
The token cache is something you will have to make, here is the example from the example app:
public class AdalDistributedTokenCache : TokenCache
{
private readonly IDistributedCache _cache;
private readonly string _userId;
public AdalDistributedTokenCache(IDistributedCache cache, string userId)
{
_cache = cache;
_userId = userId;
BeforeAccess = BeforeAccessNotification;
AfterAccess = AfterAccessNotification;
}
private string GetCacheKey()
{
return $"{_userId}_TokenCache";
}
private void BeforeAccessNotification(TokenCacheNotificationArgs args)
{
Deserialize(_cache.Get(GetCacheKey()));
}
private void AfterAccessNotification(TokenCacheNotificationArgs args)
{
if (HasStateChanged)
{
_cache.Set(GetCacheKey(), Serialize(), new DistributedCacheEntryOptions
{
AbsoluteExpirationRelativeToNow = TimeSpan.FromDays(1)
});
HasStateChanged = false;
}
}
}
The token cache here uses a distributed cache to store tokens, so that all instances serving your app have access to the tokens. They are cached per user, so you can retrieve a token for any user later.
Then when you want to get a token and use MS graph, you'd do something like (important stuff in GetAccessTokenAsync()):
[Authorize]
public class HomeController : Controller
{
private static readonly HttpClient Client = new HttpClient();
private readonly IDistributedCache _cache;
private readonly IConfiguration _config;
public HomeController(IDistributedCache cache, IConfiguration config)
{
_cache = cache;
_config = config;
}
[AllowAnonymous]
public IActionResult Index()
{
return View();
}
public async Task<IActionResult> MsGraph()
{
HttpResponseMessage res = await QueryGraphAsync("/me");
ViewBag.GraphResponse = await res.Content.ReadAsStringAsync();
return View();
}
private async Task<HttpResponseMessage> QueryGraphAsync(string relativeUrl)
{
var req = new HttpRequestMessage(HttpMethod.Get, "https://graph.microsoft.com/v1.0" + relativeUrl);
string accessToken = await GetAccessTokenAsync();
req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
return await Client.SendAsync(req);
}
private async Task<string> GetAccessTokenAsync()
{
string authority = _config["Authentication:Authority"];
string userId = User.FindFirst("http://schemas.microsoft.com/identity/claims/objectidentifier").Value;
var cache = new AdalDistributedTokenCache(_cache, userId);
var authContext = new AuthenticationContext(authority, cache);
string clientId = _config["Authentication:ClientId"];
string clientSecret = _config["Authentication:ClientSecret"];
var credential = new ClientCredential(clientId, clientSecret);
var result = await authContext.AcquireTokenSilentAsync("https://graph.microsoft.com", credential, new UserIdentifier(userId, UserIdentifierType.UniqueId));
return result.AccessToken;
}
}
There we acquire a token silently (using the token cache), and attach it to requests to the Graph.

Stuck on AsyncPost in Web API

I am really stuck on this as I have searched far and wide for a solution for an asyncpost using Web API but couldnt find anything. Essentially, its got to make a POST call using HttpClient to the relevant controller class AddMenuItem using Web API but it just doesn't work. It simply throws an error of a 404 Error and cannot see the controller method. Any reasons why and solution for this would be very helpful!
// Async Post Call
public static async void asyncPost()
{
using (var client = new HttpClient())
{
try
{
var values = new System.Collections.Generic.Dictionary<string, string>();
values.Add("ItemName", "Pepperoni Pizza");
var content = new FormUrlEncodedContent(values);
string baseAddress = "http://localhost:9000/";
HttpResponseMessage response3 = await client.PostAsync(baseAddress + "api/values/AddMenuItem", content);
if (response3.StatusCode == System.Net.HttpStatusCode.OK)
{
// Do something...
}
}
catch (OperationCanceledException) { }
}
}
// POST api/values
public void AddMenuItem([FromBody]string itemName)
{
//Should go in here when PostAync is called
}
Don't use async void; use async Task instead.
public static async Task PostAsync()
Then your controller can call it with await:
public async Task AddMenuItem([FromBody]string itemName)
{
await PostAsync(..);
}

Testing Web API controllers protected with [Authorize]

I have just added token-based security to my Web API using ASP.net identity OWIN and OAuth 2. As a result of this I am getting 405 unauthorized error on all my tests. How can I mock the securitycontext. I've seen some samples where other have overridden the Thread.CurrentPrincipal but unsure if this is the correct way.
sample test
[TestMethod]
public void Verify_GetReferenceData_Http_Get()
{
var configAE = new HttpSelfHostConfiguration("http://localhost:53224");
Konstrukt.SL.AggregationEngine.WebApiConfig.Register(configAE, new AutoFacStandardModule());
using (HttpSelfHostServer serverAE = new HttpSelfHostServer(configAE))
{
serverAE.OpenAsync().Wait();
HttpResponseMessage responseMessage;
using (var client = new HttpClient())
{
responseMessage =
client.GetAsync(
"http://localhost:53224/AggregationEngine/GetReferenceData/1/Dummy/..."
).Result;
serverAE.CloseAsync().Wait();
configAE.Dispose();
Assert.AreEqual(HttpStatusCode.OK, responseMessage.StatusCode, "Wrong http status returned");
}
}
}
sample controller
public class GetReferenceDataController : ApiController
{
private readonly IDeserializeHelper _deserializeHelper;
private readonly IGetBudgetData _getBudgetData;
private readonly IRevision _revision;
public GetReferenceDataController(IDeserializeHelper deserializeHelper, IGetBudgetData getBudgetData, IRevision revision)
{
_deserializeHelper = deserializeHelper;
_getBudgetData = getBudgetData;
_revision = revision;
}
[Authorize]
[Route("AggregationEngine/GetReferenceData/{budgetId}/{userId}/{filterJSON}")]
[HttpGet]
public HttpResponseMessage Get(int budgetId, string userId, [FromUri]string filterJSON)
{
FlatBudgetData data = new FlatBudgetData();
IDataQueryFilter dataQueryFilter = _deserializeHelper.DeserializeToFilterObject(EntityType.UserReferenceLine, _revision.GetLatesRevision(budgetId), userId, filterJSON);
data.Data = _getBudgetData.GetData(dataQueryFilter);
string jsonFlatBudget = JsonConvert.SerializeObject(data);
var jsonResponse = new HttpResponseMessage()
{
Content = new StringContent(jsonFlatBudget)
};
jsonResponse.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
return jsonResponse;
}
}
I followed the first answer in the following stack thread and got it working. Integration Test Web Api With [Authorize]

How to get Json Post Values with asp.net webapi

i'm making a request do a asp.net webapi Post Method, and i'm not beeing able to get a request variable.
Request
jQuery.ajax({ url: sURL, type: 'POST', data: {var1:"mytext"}, async: false, dataType: 'json', contentType: 'application/x-www-form-urlencoded; charset=UTF-8' })
.done(function (data) {
...
});
WEB API Fnx
[AcceptVerbs("POST")]
[ActionName("myActionName")]
public void DoSomeStuff([FromBody]dynamic value)
{
//first way
var x = value.var1;
//Second way
var y = Request("var1");
}
i Cannot obtain the var1 content in both ways... (unless i create a class for that)
how should i do that?
First way:
public void Post([FromBody]dynamic value)
{
var x = value.var1.Value; // JToken
}
Note that value.Property actually returns a JToken instance so to get it's value you need to call value.Property.Value.
Second way:
public async Task Post()
{
dynamic obj = await Request.Content.ReadAsAsync<JObject>();
var y = obj.var1;
}
Both of the above work using Fiddler. If the first option isn't working for you, try setting the content type to application/json to ensure that the JsonMediaTypeFormatter is used to deserialize the content.
After banging my head around for a while on this and trying many different things I ended up putting some breakpoints on the API server and found the key value pairs stuffed down in the request. After I knew where they were, it was easy to access them. However, I have only found this method to work with WebClient.UploadString. However, it does work easily enough and allows you to load up as many parameters as you like and very easily access them server side. Note that I am targeting .net 4.5.
CLIENT SIDE
// Client request to POST the parameters and capture the response
public string webClientPostQuery(string user, string pass, string controller)
{
string response = "";
string parameters = "u=" + user + "&p=" + pass; // Add all parameters here.
// POST parameters could also easily be passed as a string through the method.
Uri uri = new Uri("http://localhost:50000/api/" + controller);
// This was written to work for many authorized controllers.
using (WebClient wc = new WebClient())
{
try
{
wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
response = wc.UploadString(uri, login);
}
catch (WebException myexp)
{
// Do something with this exception.
// I wrote a specific error handler that runs on the response elsewhere so,
// I just swallow it, not best practice, but I didn't think of a better way
}
}
return response;
}
SERVER SIDE
// In the Controller method which handles the POST request, call this helper:
string someKeyValue = getFormKeyValue("someKey");
// This value can now be used anywhere in the Controller.
// Do note that it could be blank or whitespace.
// This method just gets the first value that matches the key.
// Most key's you are sending only have one value. This checks that assumption.
// More logic could be added to deal with multiple values easily enough.
public string getFormKeyValue(string key)
{
string[] values;
string value = "";
try
{
values = HttpContext.Current.Request.Form.GetValues(key);
if (values.Length >= 1)
value = values[0];
}
catch (Exception exp) { /* do something with this */ }
return value;
}
For more info on how to handle multi-value Request.Form Key/Value pairs, see:
http://msdn.microsoft.com/en-us/library/6c3yckfw(v=vs.110).aspx
I searched all morning to find an answer that depicted both client and server code, then finally figured it out.
Brief intro - The UI is an MVC 4.5 project that implements a standard view. The server side is an MVC 4.5 WebApi. The objective was to POST the model as JSON and subsequently update a database. It was my responsibility to code both the UI and backend. Below is the code. This worked for me.
Model
public class Team
{
public int Ident { get; set; }
public string Tricode { get; set; }
public string TeamName { get; set; }
public string DisplayName { get; set; }
public string Division { get; set; }
public string LogoPath { get; set; }
}
Client Side (UI Controller)
private string UpdateTeam(Team team)
{
dynamic json = JsonConvert.SerializeObject(team);
string uri = #"http://localhost/MyWebApi/api/PlayerChart/PostUpdateTeam";
try
{
WebRequest request = WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/json; charset=utf-8";
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write(json);
streamWriter.Flush();
streamWriter.Close();
}
WebResponse response = (HttpWebResponse)request.GetResponse();
using (var streamReader = new StreamReader(response.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
}
}
catch (Exception e)
{
msg = e.Message;
}
}
Server Side (WebApi Controller)
[Route("api/PlayerChart/PostUpdateTeam")]
[HttpPost]
public string PostUpdateTeam(HttpRequestMessage context)
{
var contentResult = context.Content.ReadAsStringAsync();
string result = contentResult.Result;
Team team = JsonConvert.DeserializeObject<Team>(result);
//(proceed and update database)
}
WebApiConfig (route)
config.Routes.MapHttpRoute(
name: "PostUpdateTeam",
routeTemplate: "api/PlayerChart/PostUpdateTeam/{context}",
defaults: new { context = RouteParameter.Optional }
);
Try this.
public string Post(FormDataCollection form) {
string par1 = form.Get("par1");
// ...
}
try using following way
[AcceptVerbs("POST")]
[ActionName("myActionName")]
public static void DoSomeStuff(var value)
{
//first way
var x = value;
}

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