Yahoo Weather API C# Example

YWSample.cs

// Yahoo Weather API C# Sample Code
// Code sample offered under the terms of the CC0 Public Domain designation. See https://creativecommons.org/publicdomain/zero/1.0/legalcode/ for terms.
// Author: Eugene Plotnikov


using System;
using System.Net;
using System.Security.Cryptography;
using System.Text;

class YWSample {

 const string cURL              = "https://weather-ydn-yql.media.yahoo.com/forecastrss";
 const string cAppID            = "test-app-id";
 const string cConsumerKey      = "your-consumer-key";
 const string cConsumerSecret   = "your-consumer-secret";
 const string cOAuthVersion     = "1.0";
 const string cOAuthSignMethod  = "HMAC-SHA1";
 const string cWeatherID        = "woeid=727232";  // Amsterdam, The Netherlands
 const string cUnitID           = "u=c";           // Metric units
 const string cFormat           = "xml";

 static string _get_timestamp () {
  TimeSpan lTS = DateTime.UtcNow - new DateTime ( 1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc );
  return Convert.ToInt64 ( lTS.TotalSeconds ).ToString ();
 }  // end _get_timestamp

 static string _get_nonce () {
  return Convert.ToBase64String (
   new ASCIIEncoding ().GetBytes (
    DateTime.Now.Ticks.ToString ()
   )
  );
 }  // end _get_nonce
 
 // NOTE: whenever the value of a parameter is changed, say cUnitID "u=c" => "location=sunnyvale,ca"
 // The order in lSign needs to be updated, i.e. re-sort lSign
 // Please don't simply change value of any parameter without re-sorting.
 static string _get_auth () {
  string retVal;
  string lNonce = _get_nonce     ();
  string lTimes = _get_timestamp ();
  string lCKey  = string.Concat ( cConsumerSecret, "&" );
  string lSign  = string.Format (  // note the sort order !!!
   "format={0}&"                 +
   "oauth_consumer_key={1}&"     +
   "oauth_nonce={2}&"            +
   "oauth_signature_method={3}&" +
   "oauth_timestamp={4}&"        +
   "oauth_version={5}&"          +
   "{6}&{7}",
   cFormat,
   cConsumerKey,
   lNonce,
   cOAuthSignMethod,
   lTimes,
   cOAuthVersion,
   cUnitID,
   cWeatherID
  );
  
  lSign = string.Concat (
   "GET&", Uri.EscapeDataString ( cURL ), "&", Uri.EscapeDataString ( lSign )
  );
  
  using (   var lHasher = new HMACSHA1 (  Encoding.ASCII.GetBytes( lCKey )  )   ) {
   lSign = Convert.ToBase64String (
    lHasher.ComputeHash (  Encoding.ASCII.GetBytes ( lSign )  )
   );
  }  // end using
  
  return "OAuth "                     +
         "oauth_consumer_key=\""     + cConsumerKey     + "\", " +
         "oauth_nonce=\""            + lNonce           + "\", " +
         "oauth_timestamp=\""        + lTimes           + "\", " +
         "oauth_signature_method=\"" + cOAuthSignMethod + "\", " +
         "oauth_signature=\""        + lSign            + "\", " +
         "oauth_version=\""          + cOAuthVersion    + "\"";
          
 }  // end _get_auth

 public static void Main ( string[] args ) {

  const string lURL = cURL + "?" + cWeatherID + "&" + cUnitID +"&format=" + cFormat;
  
  var lClt = new WebClient ();
  
  lClt.Headers.Set (  "Content-Type",  "application/" + cFormat );
  lClt.Headers.Add (  "X-Yahoo-App-Id",  cAppID                   );
  lClt.Headers.Add (  "Authorization", _get_auth ()             );

  Console.WriteLine( "Downloading Yahoo weather report . . ." );
  
  byte[] lDataBuffer = lClt.DownloadData ( lURL );
  
  string lOut = Encoding.ASCII.GetString ( lDataBuffer );
  
  Console.WriteLine ( lOut );

  Console.Write ( "Press any key to continue . . . " );
  Console.ReadKey ( true );

 }  // end Main
 
}  // end YWSample

I have test this with location name.
please check my sample code.

public class CheckWeatherDetail
{

    public static string TestWeather()
    {
        const string url = cURL + "?location=sunnyvale" + "&" + cUnitID + "&format=" + cFormat;
        using (var client = new WebClient())
        {
            string responseText = string.Empty;                 try
            {
                string headerString = _get_auth();

                WebClient webClient = new WebClient();
                webClient.Headers[HttpRequestHeader.ContentType] = "application/json";
                webClient.Headers[HttpRequestHeader.Authorization] = headerString;
                webClient.Headers.Add("X-Yahoo-App-Id", cAppID);                   
                byte[] reponse = webClient.DownloadData(url);
                string lOut = Encoding.ASCII.GetString(reponse);
            }
            catch (WebException exception)
            {
                if (exception.Response != null)
                {
                    var responseStream = exception.Response.GetResponseStream();
                    if (responseStream != null)
                    {
                        using (var reader = new StreamReader(responseStream))
                        {
                            responseText = reader.ReadToEnd();
                           
                            
                            return responseText;
                        }
                    }
                }

            }
            return string.Empty;
        }
    }

    const string cURL = "https://weather-ydn-yql.media.yahoo.com/forecastrss";
    const string cAppID = "YOurKEY";
    const string cConsumerKey = "YourcConsumerKey";
    const string cConsumerSecret = "YourcConsumerSecret";
    const string cOAuthVersion = "1.0";
    const string cOAuthSignMethod = "HMAC-SHA1";
    const string cWeatherID = "sunnyvale";  // Amsterdam, The Netherlands
    const string cUnitID = "u=c";           // Metric units
    const string cFormat = "json";

    static string _get_timestamp()
    {
        TimeSpan lTS = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
        return Convert.ToInt64(lTS.TotalSeconds).ToString();
    }  // end _get_timestamp

    static string _get_nonce()
    {
        return Convert.ToBase64String(
         new ASCIIEncoding().GetBytes(
          DateTime.Now.Ticks.ToString()
         )
        );
    }  // end _get_nonce

    // NOTE: whenever the value of a parameter is changed, say cUnitID "u=c" => "location=sunnyvale,ca"
    // The order in lSign needs to be updated, i.e. re-sort lSign
    // Please don't simply change value of any parameter without re-sorting.
    static string _get_auth()
    {
        string retVal;
        string lNonce = _get_nonce();
        string lTimes = _get_timestamp();
        string lCKey = string.Concat(cConsumerSecret, "&");
        string lSign = string.Format(  // note the sort order !!!
         "format={0}&" +
         "location={1}&"+
         "oauth_consumer_key={2}&" +
         "oauth_nonce={3}&" +
         "oauth_signature_method={4}&" +
         "oauth_timestamp={5}&" +
         "oauth_version={6}&" +
         "{7}",
         cFormat,
         cWeatherID,
         cConsumerKey,
         lNonce,
         cOAuthSignMethod,
         lTimes,
         cOAuthVersion,
         cUnitID
        
        );

        lSign = string.Concat(
         "GET&", Uri.EscapeDataString(cURL), "&", Uri.EscapeDataString(lSign)
        );

        using (var lHasher = new HMACSHA1(Encoding.ASCII.GetBytes(lCKey)))
        {
            lSign = Convert.ToBase64String(
             lHasher.ComputeHash(Encoding.ASCII.GetBytes(lSign))
            );
        }  // end using

        return "OAuth " +
               "oauth_consumer_key=\"" + cConsumerKey + "\", " +
               "oauth_nonce=\"" + lNonce + "\", " +
               "oauth_timestamp=\"" + lTimes + "\", " +
               "oauth_signature_method=\"" + cOAuthSignMethod + "\", " +
               "oauth_signature=\"" + lSign + "\", " +
               "oauth_version=\"" + cOAuthVersion + "\"";

    }  // end _get_auth
}

here is the complete example of Yahoo weather by location name.

https://github.com/abdulkhaliqsixlogics/Yahoo-Weather-/blob/master/YahooWeatherSample.cs

Hi, maybe someone knows how to download weather data by parameters lat and lon?

how to download weather data by ZIP and LatLong?

retVal is not used here
So we do not need it.
You may update from my fork