Retrieving From A WEBAPI Into a textview in xamarin

Chioma Joshua

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im new to programming and i need help in

retrieving the results from the webapi to my textview on xamarin??

this is the WEBAPI address : http://api.iolab.net/v1/exams?access-token=

need help.

10 Replies

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Bhuvanesh Mohankumar10y ago
Accepted answer
Hi Chioma,
Please modify the response to the proper Json format.
Sample Json:
[{"Name":"Chioma","ID":1234}]
Now your response has some unwanted code "
or you can use the below regular expression to get valid Json
var validJsonData = data.replace(/[^a-z0-9\s",{}:[]"]/gi, '').replace(/[_\s]/g, ' ');
once you clean up your JSON content check the content is proper by pasting to online parser link provided.
http://json.parser.online.fr/
Now you can parse the Valid Jsonand get assigned to object you require and manipulate in Xamarin.
Accept as answer, if helpful.
0
Chioma Joshua10y ago
Thank You Bhuvanesh.... Nice To Meet You....
0
Bhuvanesh Mohankumar10y ago
You can also check for the "HTTPCollectionKeys",as I searched this is due to some settings issue the error mayoccurred.
Chioma, Will try to post if I get any update on this.
0
Chioma Joshua10y ago
Thank You, Bhuvanesh.. Its a mobile application..
0
Bhuvanesh Mohankumar10y ago
Can you add this line in your configuration file [Web.config]

key="aspnet:MaxHttpCollectionKeys" value="2001" />
0
Chioma Joshua10y ago
hey bhuvanesh,
did as you suggested but its still returning the same error:
System.InvalidOperationException: Operation is not valid due to the current state of the object.

plus the result of the webapi is in an array...
0
Bhuvanesh Mohankumar10y ago
Thanks Chioma,
I believe this is due to the object may not available or disposed before you access that.
Ican see you used -> using (WebResponse response = await request.GetResponseAsync())....
When the "using" is used the object will be disposed automatically, may be due to which current object is out of scope.
Can you try removing the using and check, once that works then we can optimize the code by using keyword.
0
Chioma Joshua10y ago
Hello Bhuvanesh,
thanks for the assistance so far... i really do appreciate..
Still have a problem... i'll paste my code.. please help me.. tried debugging but its not coming through...

its returning this error:
"System.InvalidOperationException: Operation is not valid due to the current state of the object."

Code Used..:
button.Click += async (sender, e) =>
{
string url = "http://api.iolab.net/v1/exams?access-token";
// Fetch the weather information asynchronously, parse the results,
// then update the screen:
JsonValue json = await FetchExamAsync(url);
ParseAndDisplay(json);
};
}
private async Task FetchExamAsync(string url)
{
// Create an HTTP web request using the URL:
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(new Uri(url));
request.ContentType = "application/json";
request.Method = "GET";
// Send the request to the server and wait for the response:
using (WebResponse response = await request.GetResponseAsync())
{
// Get a stream representation of the HTTP web response:
using (Stream stream = response.GetResponseStream())
{
// Use this stream to build a JSON document object:
JsonValue jsonDoc = await Task.Run(() => JsonObject.Load(stream));
Console.Out.WriteLine("Response: {0}", jsonDoc.ToString());
// Return the JSON document:
return jsonDoc;
}
}
}
private void ParseAndDisplay(JsonValue json)
{
TextView itemtext = FindViewById(Resource.Id.textView1);
JsonValue weatherResults = json["items"];
itemtext.Text = weatherResults["shortname"];
}

0
Chioma Joshua10y ago
Bhuvanesh i dont know how to.. please help me..
0
Bhuvanesh Mohankumar10y ago
Can you returnas JSON from the WEB API and try to read the JSON data in your Xamarin.
+1