Xamarin.Forms problems sending large picture over HttpClient SendAsync in Json format

Question

from my Xamarin.Forms app I'm sending a picture and other fields to the server using HttpClient in Json format. If I send a little picture I've got with my front camera it's working fine, if I send a larger picture I've got with the rear camera it doesn't work and I always get an exception: "Excepional error".

I tried to create the same code in a windows form application and it's working fine also with large images, but not from my App.

I have already modified on the server web.config to increase json content size:

<jsonSerialization maxJsonLength="50000000"/>

Can someone help ?! Thanks!!

This is the code on my app:

public async static Task<MyAppDataModels.Common.WsResponse> PostPhotoFromUser(int catalogItemId, int objReferenceId, int languageId, byte[] fileContent)
    {
        MyAppDataModels.Common.WsResponse MyResponse = new MyAppDataModels.Common.WsResponse();
        try
        {                
            HttpClient MyHttpClient = new HttpClient();
            MyHttpClient.Timeout = TimeSpan.FromSeconds(520);
            MyHttpClient.BaseAddress = new Uri(string.Format("{0}/Application/ApplicationPostPhotoFromUser", MyAppSettings.ServerApiUrl));
            MyHttpClient.DefaultRequestHeaders.Accept.Clear();
            MyHttpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            MyHttpClient.DefaultRequestHeaders.AcceptCharset.Clear();
            MyHttpClient.DefaultRequestHeaders.AcceptCharset.Add(new StringWithQualityHeaderValue("utf-8"));
            HttpRequestMessage MyWsRequest = new HttpRequestMessage(HttpMethod.Post, MyHttpClient.BaseAddress);

            dynamic MyObjData = new JObject();
            MyObjData["CatalogItemId"] = catalogItemId;
            MyObjData["ObjReferenceId"] = objReferenceId;
            MyObjData["UserId"] = string.Empty;
            MyObjData["LanguageId"] = languageId;
            MyObjData["Picture"] = fileContent;

            string MySerializedPostedData = JsonConvert.SerializeObject(MyObjData);
            MyWsRequest.Content = new StringContent(MySerializedPostedData, Encoding.UTF8, "application/json");

            HttpResponseMessage MyWsResponse = await MyHttpClient.SendAsync(MyWsRequest, HttpCompletionOption.ResponseHeadersRead);
            MyWsResponse.EnsureSuccessStatusCode();
            var MyContentResponse = await MyWsResponse.Content.ReadAsStringAsync();
            MyResponse.ResponseId = MyAppConstants.Constants.ResponseCode.Successfull;
        }
        catch (Exception ex)
        {
            MyResponse.ResponseId = MyAppConstants.Constants.ResponseCode.ErrorWhileProcessingRequest;
            MyResponse.ResponseErrorMessage = ex.Message;
        }
        return MyResponse;
    }

I'm using Xamarin.Forms and the code it's inside PCL, in this case where I have the problem I'm running the app on Android — Stefano, Apr 26 '16 at 21:22

Mina Wissa · Accepted Answer · 2016-04-27T22:25:29.767

0

From the stacktrace,

System.Net.WebExceptionStatus.ProtocolError

means that the server responded with some 40x error, maybe 401 (Acess Denied) or something similar.

you can wrap your call in a:

try
{
}
catch(WebException ex){
}

then check the exceptions Status and cast the exception's response like that:

((HttpWebResponse)e.Response).StatusDescription

to get more info about what has gone wrong on the server.

EDIT: Because you're uploading large files, you can resolve the "maximum request length exceeded exception", you need to modify your server's (ASP.NET for example) web.config file to accept large request size:

<configuration>
    <system.web>
        <httpRuntime maxRequestLength="50000" />
    </system.web>
</configuration>

edited Apr 27 '16 at 22:25

answered Apr 26 '16 at 22:06

Mina Wissa

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From the TryCatch I got this message: ExceptionMaximum request length exceeded. at System.Web.HttpRequest.GetEntireRawContent() at System.Web.HttpRequest.get_InputStream() at ApplicationPostPhotoFromUser(HttpRequestMessage httRequestMessage) in D:\xxx\ApplicationController.vb:line 267. In this line I have the following code where I read the request content: Dim MyStreamReader As System.IO.StreamReader = New System.IO.StreamReader(HttpContext.Current.Request.InputStream) – Stefano Apr 27 '16 at 21:51
please check the updated answer, you need to increase the max request size on your server config. – Mina Wissa Apr 27 '16 at 21:57
I added this line in my web.config and restarted IIS, but now I get 500 (Internal server error) – Stefano Apr 27 '16 at 22:23
Sorry, I'm not sure, maybe you can debug your server side method that accepts the uploaded images and see the exact exception details. – Mina Wissa Apr 27 '16 at 22:26
I've been able to solve the 500 (Internal server error) then I got an error on JSON JavaScriptSerializer length of the string which exceeded the value set on the maxJsonLength property. I have increased this value on the code (MyJs.MaxJsonLength = Int32.MaxValue) and now it's working!! MANY thanks !!!!! – Stefano Apr 27 '16 at 22:58
Great, I'm glad to hear that. Good luck – Mina Wissa Apr 28 '16 at 09:15

Xamarin.Forms problems sending large picture over HttpClient SendAsync in Json format

1 Answers1