I am developing my first windows App and I am facing some Problems while parsing an Xml,the code is as shown below
public void TimeParsing(string lat, string lon)
{
string urlbeg = "http://api.geonames.org/timezone?lat=";
string urlmid = "&lng=";
string urlend = "&username=dheeraj_kumar";
WebClient downloader = new WebClient();
Uri uri = new Uri(urlbeg + lat + urlmid + lon + urlend, UriKind.Absolute);
downloader.DownloadStringCompleted += new DownloadStringCompletedEventHandler(TimeDownloaded);
//downloader.DownloadStringCompleted += new DownloadStringCompletedEventHandler(TimeDownloaded);
downloader.DownloadStringAsync(uri);
}
private void TimeDownloaded(object sender, DownloadStringCompletedEventArgs e)
{
if (e.Result == null || e.Error != null)
{
MessageBox.Show("Invalid");
}
else
{
XDocument document = XDocument.Parse(e.Result);
var data1 = from query in document.Descendants("geoname")
select new Country
{
CurrentTime = (string)query.Element("time"),
};
foreach (var d in data1)
{
time = d.CurrentTime;
MessageBox.Show(d.CurrentTime);
// country = d.CountryName;
}
}
}
The problem is that the Delegate TimeDownloaded is not being called. I used the same technique is parse a different URL and it was done easily but its not working in this case.Kindly Help me as I am pretty new to this field.
Thanks in advance.
Theres a few misses regarding fetching the nodes
The output is geonames/timezone/time, it's corrected below, also testable using the method DownloadStringTaskAsync instead
[TestClass]
public class UnitTest1
{
[TestMethod]
public async Task TestMethod1()
{
await TimeParsing("-33.8674869", "151.20699020000006");
}
public async Task TimeParsing(string lat, string lon)
{
var urlbeg = "http://api.geonames.org/timezone?lat=";
var urlmid = "&lng=";
var urlend = "&username=dheeraj_kumar";
var downloader = new WebClient();
var uri = new Uri(urlbeg + lat + urlmid + lon + urlend, UriKind.Absolute);
downloader.DownloadStringCompleted += TimeDownloaded;
var test = await downloader.DownloadStringTaskAsync(uri);
Console.WriteLine(test);
}
private void TimeDownloaded(object sender, DownloadStringCompletedEventArgs e)
{
if (e.Result == null || e.Error != null)
{
Console.WriteLine("Invalid");
}
else
{
var document = XDocument.Parse(e.Result);
var data1 = from query in document.Descendants("timezone")
select new Country
{
CurrentTime = (string)query.Element("time"),
};
foreach (var d in data1)
{
Console.WriteLine(d.CurrentTime);
}
}
}
}
internal class Country
{
public string CurrentTime { get; set; }
}
}
you can use the below mentioned code.
Uri uri = new Uri(urlbeg + lat + urlmid + lon + urlend, UriKind.Absolute);
HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(uri);
//This time, our method is GET.
WebReq.Method = "GET";
//From here on, it's all the same as above.
HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
//Now, we read the response (the string), and output it.
Stream Answer = WebResp.GetResponseStream();
StreamReader _Answer = new StreamReader(Answer);
string s = _Answer.ReadToEnd();
XDocument document = XDocument.Parse(s);
var data1 = from query in document.Descendants("geoname")
select new Country
{
CurrentTime = (string)query.Element("time"),
};
foreach (var d in data1)
{
time = d.CurrentTime;
MessageBox.Show(d.CurrentTime);
// country = d.CountryName;
}
for Windows Phone 8 you have to implement the getResponse Method.
public static System.Threading.Tasks.Task<System.Net.WebResponse> GetResponseAsync(this System.Net.WebRequest wr)
{
return Task<System.Net.WebResponse>.Factory.FromAsync(wr.BeginGetResponse, wr.EndGetResponse, null);
}
Related
I have an asp.net mvc application were i send sms messages with URL to clients. message and URL is sent correctly but when i click on the link it does not open correctly, example there is no data passed from database, example if you click the following url, there is no data passed to view: http://binvoicing.com/InvoiceAddlines/PaymentPreview?originalId=11&total=585.00
Here code:
public ActionResult SendSms(string cellnumber, int? id, string rt, string tenant, decimal? total, string userloggedin)
{
StreamReader objReader;
WebClient client = new WebClient();
int payid = 0;
int paypalaid = 0;
string UrL = "";
string pass = "mypassword";
//string cell = cellnumber;
string user = "username";
var pay = from e in db.PayfastGateways
where e.userId == userloggedin
select e;
var paya = pay.ToList();
foreach (var y in paya)
{
payid = y.ID;
}
var pal = from e in db.PaypalGateways
where e.userId == userloggedin
select e;
var payla = pal.ToList();
foreach (var y in payla)
{
paypalaid = y.ID;
}
string url = Url.Action("PaymentPreview", "InvoiceAddlines", new System.Web.Routing.RouteValueDictionary(new { originalId = id, total = total }), "http", Request.Url.Host);
if (payid == 0 && paypalaid == 0)
{
UrL = "";
}
else
{
UrL = url;
}
string mess = " Dear Customer, please click on the following link to view generated invoice, you can also pay your invoice online." + UrL;
string message = HttpUtility.UrlEncode(mess, System.Text.Encoding.GetEncoding("ISO-8859-1"));
string baseurl =
"http://bulksms.2way.co.za/eapi/submission/send_sms/2/2.0?" +
"username=" + user + "&" +
"password=" + pass + "&" +
"message=" + message + "&" +
"msisdn=" + cellnumber;
WebRequest wrGETURL;
wrGETURL = WebRequest.Create(baseurl);
HttpUtility.UrlEncode("http://www.vcskicks.com/c#");
try
{
Stream objStream;
objStream = wrGETURL.GetResponse().GetResponseStream();
objReader = new StreamReader(objStream);
objReader.Close();
}
catch (Exception ex)
{
ex.ToString();
}
ViewBag.cellnumber = cellnumber;
ViewBag.id = id;
ViewBag.rt = rt;
ViewBag.tenant = tenant;
ViewBag.total = total;
ViewBag.UrL = UrL;
return View();
}
SMS send url like http://binvoicing.com/InvoiceAddlines/PaymentPreview?originalId=11&total=585.00
Here Is my PaymentPreview method:
public ActionResult PaymentPreview(int? originalId, decimal? total)
{
TempData["keyEditId"] = originalId;
ViewBag.ind = originalId;
decimal totals = 0;
totals = (decimal)total;
var line = from e in db.InvoiceAddlines
where e.AddlineID == originalId
select e;
var addlines = line.ToList();
foreach (var y in addlines)
{
decimal? de = Math.Round(totals);
string tots = de.ToString();
y.Total = tots;
db.SaveChanges();
}
return View(db.InvoiceAddlines.ToList());
}
Hope someone can assist, thanks.
I think there is something wrong with the way URL is being built. See if this works -
Change this part of your code
string url = Url.Action("PaymentPreview", "InvoiceAddlines", new System.Web.Routing.RouteValueDictionary(new { originalId = id, total = total }), "http", Request.Url.Host);
To
string url = Url.Action("PaymentPreview", "InvoiceAddlines", new { originalId = id, total = total })
I have to update my database from geocode to get longitude and latitude of address stored in database.
For that I created one console application. Daily I can update 25000 records from google per user, And I am executing my console from different 3 machines everyday since last 4 to 5 days.
But I am getting OVER_QUERY_LIMIT status from today and I am not able to update database.
What should i do for this?
Here is my code to get Longitude-latitude of console:
protected static void FindLocation(string strLocation, out string lat, out string lng, out string Output)
{
StreamWriter myWriter;
System.Net.HttpWebRequest geoRequest;
string googResponse;
googResponse = "";
lat = "";
lng = "";
Output = "";
string abc = "";
string strRequestURL;
strRequestURL = "https://maps.googleapis.com/maps/api/geocode/xml?address=" + strLocation + "&sensor=false";
try
{
geoRequest = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(strRequestURL);
geoRequest.Method = "POST";
geoRequest.KeepAlive = true;
UTF8Encoding encoding = new UTF8Encoding();
byte[] bytes = encoding.GetBytes(strRequestURL);
geoRequest.ContentLength = bytes.Length;
using (Stream writeStream = geoRequest.GetRequestStream())
{
writeStream.Write(bytes, 0, bytes.Length);
writeStream.Close();
}
System.Net.HttpWebResponse geoResponse;
geoResponse = (System.Net.HttpWebResponse)geoRequest.GetResponse();
if (geoResponse != null)
{
XPathDocument document = new XPathDocument(geoResponse.GetResponseStream());
XPathNavigator navigator = document.CreateNavigator();
// get response status
XPathNodeIterator statusIterator = navigator.Select("/GeocodeResponse/status");
while (statusIterator.MoveNext())
{
if (statusIterator.Current.Value != "OK")
{
if (statusIterator.Current.Value == "OVER_QUERY_LIMIT")
{
}
Output = "Failed";
}
else
{
Output = statusIterator.Current.Value;
}
}
// get results
XPathNodeIterator resultIterator = navigator.Select("/GeocodeResponse/result");
while (resultIterator.MoveNext())
{
XPathNodeIterator geometryIterator = resultIterator.Current.Select("geometry");
while (geometryIterator.MoveNext())
{
XPathNodeIterator locationIterator = geometryIterator.Current.Select("location");
while (locationIterator.MoveNext())
{
XPathNodeIterator latIterator = locationIterator.Current.Select("lat");
while (latIterator.MoveNext())
{
lat = latIterator.Current.Value;
}
XPathNodeIterator lngIterator = locationIterator.Current.Select("lng");
while (lngIterator.MoveNext())
{
lng = lngIterator.Current.Value;
}
}
}
}
}
else
{
Output = "Failed";
}
}
catch (Exception ex)
{
Output = "Failed";
}
}
I have been trying a way to get the data in the next page of the result set of GET followers/list API call. I can get the default data set with the data of first 20 followers and not the others. To get the data of other followers i have to access the next page using the next_cursor but it's not working. I tried using the pseudo-code mentioned in this link. https://dev.twitter.com/docs/misc/cursoring
Is it a must to use this(this is mentioned in the dev. site):
var api-path = "https://api.twitter.com/1.1/endpoint.json?screen_name=targetUser"
Because I have been using the resource URL as,
var resource_url = "https://api.twitter.com/1.1/followers/list.json";
and I tried appending the next_cursor to the same resource URL.
var url_with_cursor = resource_url + "&cursor=" + 1463101490306580067;
and then created the request.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url_with_cursor);
but I'm getting an exception in this line when getting the response.
WebResponse response = request.GetResponse();
The error I'm getting is
The Remote Server returned an Error 401 Unauthorized
Can someone tell the exact way to do cursor-ing, or the exact way to include the cursor in the request. I'm using a asp.net C# web application.
Here's my code, The oauth_token, oauth_token_secret, oauth_consumer_key, oauth_consumer_secret, oauth_version and oauth_signature_method are defined in my application
var resource_url = "https://api.twitter.com/1.1/followers/list.json";
var cursor = "-1";
do
{
var url_with_cursor = resource_url + "&cursor=" + cursor;
// unique request details
var oauth_nonce = Convert.ToBase64String(
new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));
var timeSpan = DateTime.UtcNow
- new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
var oauth_timestamp = Convert.ToInt64(timeSpan.TotalSeconds).ToString();
// create oauth signature
var baseFormat = "oauth_consumer_key={0}&oauth_nonce={1}&oauth_signature_method={2}" +
"&oauth_timestamp={3}&oauth_token={4}&oauth_version={5}";
var baseString = string.Format(baseFormat,
oauth_consumer_key,
oauth_nonce,
oauth_signature_method,
oauth_timestamp,
oauth_token,
oauth_version
//,Uri.EscapeDataString(status)
);
baseString = string.Concat("GET&", Uri.EscapeDataString(resource_url), "&", Uri.EscapeDataString(baseString));
var compositeKey = string.Concat(Uri.EscapeDataString(oauth_consumer_secret),
"&", Uri.EscapeDataString(oauth_token_secret));
string oauth_signature;
using (HMACSHA1 hasher = new HMACSHA1(ASCIIEncoding.ASCII.GetBytes(compositeKey)))
{
oauth_signature = Convert.ToBase64String(
hasher.ComputeHash(ASCIIEncoding.ASCII.GetBytes(baseString)));
}
// create the request header
var headerFormat = "OAuth oauth_nonce=\"{0}\", oauth_signature_method=\"{1}\", " +
"oauth_timestamp=\"{2}\", oauth_consumer_key=\"{3}\", " +
"oauth_token=\"{4}\", oauth_signature=\"{5}\", " +
"oauth_version=\"{6}\"";
var authHeader = string.Format(headerFormat,
Uri.EscapeDataString(oauth_nonce),
Uri.EscapeDataString(oauth_signature_method),
Uri.EscapeDataString(oauth_timestamp),
Uri.EscapeDataString(oauth_consumer_key),
Uri.EscapeDataString(oauth_token),
Uri.EscapeDataString(oauth_signature),
Uri.EscapeDataString(oauth_version)
);
// make the request
ServicePointManager.Expect100Continue = false;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url_with_cursor);
request.Headers.Add("Authorization", authHeader);
request.Method = "GET";
request.ContentType = "application/x-www-form-urlencoded";
WebResponse response = request.GetResponse();
string result = new StreamReader(response.GetResponseStream()).ReadToEnd();
JObject j = JObject.Parse(result);
JArray data = (JArray)j["users"];
cursor = (String)j["next_cursor_str"];
} while (!cursor.Equals("0"));
Thanks.
Tweetinvi would make it somewhat easier for you.
Please visit https://github.com/linvi/tweetinvi/wiki/Get-All-Followers-Code to have an idea on how to do it including RateLimit handling.
Without considering the RateLimits, you could simply use the following code.
long nextCursor = -1;
do
{
var query = string.Format("https://api.twitter.com/1.1/followers/ids.json?screen_name={0}", username);
var results = TwitterAccessor.ExecuteCursorGETCursorQueryResult<IIdsCursorQueryResultDTO>(query, cursor: cursor).ToArray();
if (results.Any())
{
nextCursor = results.Last().NextCursor;
}
else
{
nextCursor = -1;
}
}
while (nextCursor != -1 && nextCursor != 0);
you should make a different call to authenticate, by an authorization request. Once that has been granted, you can call the webresponse with the cursor. See my sample code below (Take special note to the StartCreateCall method, where the authentication is done. The data from Twitter is then retrieved by the CallData method):
public partial class twitter_followers : System.Web.UI.Page
{
public string strTwiterFollowers { get; set; }
private List<TwiterFollowers> listFollowers = new List<TwiterFollowers>();
private string screen_name = string.Empty;
// oauth application keys
private string oauth_consumer_key = string.Empty;
private string oauth_consumer_secret = string.Empty;
// oauth implementation details
private string resource_urlFormat = "https://api.twitter.com/1.1/followers/list.json?screen_name={0}&cursor={1}";
// unique request details
private string oauth_nonce = Convert.ToBase64String(new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));
protected void Page_Load(object sender, EventArgs e)
{
//just get your request parameters from the config file.
if (!string.IsNullOrEmpty(ConfigurationManager.AppSettings[GetVariableName(() => screen_name)])) {
screen_name = ConfigurationManager.AppSettings[GetVariableName(() => screen_name)];
}
if (!string.IsNullOrEmpty(ConfigurationManager.AppSettings[GetVariableName(() => oauth_consumer_key)]))
{
oauth_consumer_key = ConfigurationManager.AppSettings[GetVariableName(() => oauth_consumer_key)];
}
if (!string.IsNullOrEmpty(ConfigurationManager.AppSettings[GetVariableName(() => oauth_consumer_secret)]))
{
oauth_consumer_secret = ConfigurationManager.AppSettings[GetVariableName(() => oauth_consumer_secret)];
}
StartCreateCall();
}
// Do the authenticate by an authorization request
private void StartCreateCall() {
// You need to set your own keys and screen name
var oAuthUrl = "https://api.twitter.com/oauth2/token";
// Do the Authenticate
var authHeaderFormat = "Basic {0}";
var authHeader = string.Format(authHeaderFormat,
Convert.ToBase64String(Encoding.UTF8.GetBytes(Uri.EscapeDataString(oauth_consumer_key) + ":" +
Uri.EscapeDataString((oauth_consumer_secret)))
));
var postBody = "grant_type=client_credentials";
HttpWebRequest authRequest = (HttpWebRequest)WebRequest.Create(oAuthUrl);
authRequest.Headers.Add("Authorization", authHeader);
authRequest.Method = "POST";
authRequest.ContentType = "application/x-www-form-urlencoded;charset=UTF-8";
authRequest.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
using (Stream stream = authRequest.GetRequestStream())
{
byte[] content = ASCIIEncoding.ASCII.GetBytes(postBody);
stream.Write(content, 0, content.Length);
}
authRequest.Headers.Add("Accept-Encoding", "gzip");
WebResponse authResponse = authRequest.GetResponse();
// deserialize into an object
TwitAuthenticateResponse twitAuthResponse;
using (authResponse)
{
using (var reader = new StreamReader(authResponse.GetResponseStream()))
{
JavaScriptSerializer js = new JavaScriptSerializer();
var objectText = reader.ReadToEnd();
twitAuthResponse = JsonConvert.DeserializeObject<TwitAuthenticateResponse>(objectText);
}
}
//now we have been granted access and got a token type with authorization token from Twitter
//in the form of a TwitAuthenticateResponse object, we can retrieve the data recursively with a cursor
CallData(twitAuthResponse, authHeader, cursor);
int totalFollowers = listFollowers.Count;
lblTotalFollowers.Text = screen_name + " has " + listFollowers.Count + " Followers";
Random objRnd = new Random();
List<TwiterFollowers> randomFollowers = listFollowers.OrderBy(item => objRnd.Next()).ToList<TwiterFollowers>();
foreach (TwiterFollowers tw in randomFollowers)
{
strTwiterFollowers = strTwiterFollowers + "<li><a target='_blank' title='" + tw.ScreenName + "' href=https://twitter.com/" + tw.ScreenName + "><img src='" + tw.ProfileImage + "'/><span>" + tw.ScreenName + "</span></a></li>";
}
}
//Retrieve the data from Twitter recursively with a cursor
private void CallData(TwitAuthenticateResponse twitAuthResponse, string authHeader, string cursor)
{
try {
JObject j = GetJSonObject(twitAuthResponse, authHeader, cursor);
JArray data = (JArray)j["users"];
if (data != null)
{
foreach (var item in data)
{
TwiterFollowers objTwiterFollowers = new TwiterFollowers();
objTwiterFollowers.ScreenName = item["screen_name"].ToString().Replace("\"", "");
objTwiterFollowers.ProfileImage = item["profile_image_url"].ToString().Replace("\"", "");
objTwiterFollowers.UserId = item["id"].ToString().Replace("\"", "");
listFollowers.Add(objTwiterFollowers);
}
JValue next_cursor = (JValue)j["next_cursor"];
if (long.Parse(next_cursor.Value.ToString()) > 0)
{
//Get the following data from Twitter with the next cursor
CallData(twitAuthResponse, authHeader, next_cursor.Value.ToString());
}
}
} catch (Exception ex)
{
//do nothing
}
}
private JObject GetJSonObject(TwitAuthenticateResponse twitAuthResponse, string authHeader, string cursor)
{
string resource_url = string.Format(resource_urlFormat, screen_name, cursor);
if (string.IsNullOrEmpty(cursor))
{
resource_url = resource_url.Substring(0, resource_url.IndexOf("&cursor"));
}
HttpWebRequest fRequest = (HttpWebRequest)WebRequest.Create(resource_url);
var timelineHeaderFormat = "{0} {1}";
fRequest.Headers.Add("Authorization", string.Format(timelineHeaderFormat, twitAuthResponse.token_type, twitAuthResponse.access_token));
fRequest.Method = "Get";
WebResponse response = fRequest.GetResponse();
string result = new StreamReader(response.GetResponseStream()).ReadToEnd();
return JObject.Parse(result);
}
private string GetVariableName<T>(Expression<Func<T>> expr)
{
var body = (MemberExpression)expr.Body;
return body.Member.Name;
}
private class TwitAuthenticateResponse
{
public string token_type { get; set; }
public string access_token { get; set; }
}
private class TwiterFollowers
{
public string ScreenName { get; set; }
public string ProfileImage { get; set; }
public string UserId { get; set; }
}
}
You are getting "401 Unauthorized"
Did you check you are setting everything right?
Credentials? Check both queries on fiddler.
I try to practice "HtmlAgilityPack ", but I am having some issues regarding this. here's what I coded, but I can not get correctly the title and the description of a web page ...
If someone can enlighten me on my mistake :)
...
public static void Main(string[] args)
{
string link = null;
string str;
string answer;
int curloc; // holds current location in response
string url = "http://stackoverflow.com/";
try
{
do
{
HttpWebRequest HttpWReq = (HttpWebRequest)WebRequest.Create(url);
HttpWReq.UserAgent = #"Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.5) Gecko/20091102 Firefox/3.5.5";
HttpWebResponse HttpWResp = (HttpWebResponse)HttpWReq.GetResponse();
//url = null; // disallow further use of this URI
Stream istrm = HttpWResp.GetResponseStream();
// Wrap the input stream in a StreamReader.
StreamReader rdr = new StreamReader(istrm);
// Read in the entire page.
str = rdr.ReadToEnd();
curloc = 0;
//WebPage result;
do
{
// Find the next URI to link to.
link = FindLink(str, ref curloc); //return the good link
Console.WriteLine("Title found: " + curloc);
//title = Title(str, ref curloc);
if (link != null)
{
Console.WriteLine("Link found: " + link);
using (System.Net.WebClient client = new System.Net.WebClient())
{
HtmlDocument htmlDoc = new HtmlDocument();
var html = client.DownloadString(url);
htmlDoc.LoadHtml(link); //chargement de HTMLAgilityPack
var htmlElement = htmlDoc.DocumentNode.Element("html");
HtmlNode node = htmlDoc.DocumentNode.SelectSingleNode("//meta[#name='description']");
if (node != null)
{
string desc = node.GetAttributeValue("content", "");
Console.Write("DESCRIPTION: " + desc);
}
else
{
Console.WriteLine("No description");
}
var titleElement =
htmlDoc.DocumentNode
.Element("html")
.Element("head")
.Element("title");
if (titleElement != null)
{
string title = titleElement.InnerText;
Console.WriteLine("Titre: {0}", title);
}
else
{
Console.WriteLine("no Title");
}
Console.Write("Done");
}
Console.Write("Link, More, Quit?");
answer = Console.ReadLine();
}
else
{
Console.WriteLine("No link found.");
break;
}
} while (link.Length > 0);
// Close the Response.
HttpWResp.Close();
} while (url != null);
}
catch{ ...}
Thanks in advance :)
Go about it this way:
HtmlNode mdnode = htmlDoc.DocumentNode.SelectSingleNode("//meta[#name='description']");
if (mdnode != null)
{
HtmlAttribute desc;
desc = mdnode.Attributes["content"];
string fulldescription = desc.Value;
Console.Write("DESCRIPTION: " + fulldescription);
}
I think your problem is here:
htmlDoc.LoadHtml(link); //chargement de HTMLAgilityPack
It should be:
htmlDoc.LoadHtml(html); //chargement de HTMLAgilityPack
LoadHtml expects a string with the HTML source, not the url.
And probably you want to change:
var html = client.DownloadString(url);
to
var html = client.DownloadString(link);
Have you used a breakpoint and gone line for line to see where the error might be occurring?
If you have, then Try something like this:
string result = string.Empty;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.google.com");
request.Method = "GET";
try
{
using (var stream = request.GetResponse().GetResponseStream())
using (var reader = new StreamReader(stream, Encoding.UTF8))
{
result = reader.ReadToEnd();
}
}
HtmlAgilityPack.HtmlDocument htmlDoc = new HtmlAgilityPack.HtmlDocument();
htmlDoc.LoadHtml(result);
Then carry over the rest of your code below the htmlDoc.LoadHtml
[HttpPost]
public ActionResult Create(WebSite website)
{
string desc = HtmlAgi(website.Url, "description");
string keyword = HtmlAgi(website.Url, "Keywords");
if (ModelState.IsValid)
{
var userId = ((CustomPrincipal)User).UserId;
r.Create(new WebSite
{
Description = desc,
Tags = keyword,
Url = website.Url,
UserId = userId,
Category = website.Category
});
return RedirectToAction("Index");
}
return View(website);
}
public string HtmlAgi(string url, string key)
{
//string.Format
var Webget = new HtmlWeb();
var doc = Webget.Load(url);
HtmlNode ourNode = doc.DocumentNode.SelectSingleNode(string.Format("//meta[#name='{0}']", key));
if (ourNode != null)
{
return ourNode.GetAttributeValue("content", "");
}
else
{
return "not fount";
}
}
I am new to C# and using Task. I was trying to run this application but my application hangs every time. When I am adding task.wait(), it keeps waiting and never returns. Any help is much appreciated.
EDIT:
I want to call DownloadString Asynchronously. And when I am doing task.Start() as suggested by "Austin Salonen" I don't get the address of location but default value in location string from returnVal. It means that location got value assigned before task got completed. How can I make sure that after task is completed only then location gets assigned returnVal.
public class ReverseGeoCoding
{
static string baseUri = "http://maps.googleapis.com/maps/api/geocode/xml?latlng={0},{1}&sensor=false";
string location = "default";
static string returnVal = "defaultRet";
string latitude = "51.962146";
string longitude = "7.602304";
public string getLocation()
{
Task task = new Task(() => RetrieveFormatedAddress(latitude, longitude));
//var result = Task.Factory.StartNew(RetrieveFormatedAddress("51.962146", "7.602304"));
task.Wait();
//RetrieveFormatedAddress("51.962146", "7.602304");
location = returnVal;
return location;
}
public static void RetrieveFormatedAddress(string lat, string lng)
{
string requestUri = string.Format(baseUri, lat, lng);
using (WebClient wc = new WebClient())
{
wc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wc_DownloadStringCompleted);
wc.DownloadStringAsync(new Uri(requestUri));
}
}
static void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
var xmlElm = XElement.Parse(e.Result);
var status = (from elm in xmlElm.Descendants()
where elm.Name == "status"
select elm).FirstOrDefault();
if (status.Value.ToLower() == "ok")
{
var res = (from elm in xmlElm.Descendants()
where elm.Name == "formatted_address"
select elm).FirstOrDefault();
//Console.WriteLine(res.Value);
returnVal = res.Value;
}
else
{
returnVal = "No Address Found";
//Console.WriteLine("No Address Found");
}
}
}
You aren't actually running the task. Debugging and checking task.TaskStatus would show this.
// this should help
task.Start();
// ... or this:
Task.Wait(Task.Factory.StartNew(RetrieveFormatedAddress("51.962146", "7.602304")));
Though if you're blocking, why start another thread to begin with?
I don't understand why you use DownloadStringCompleted event and try to make it blocking. If you want to wait the result, just use blocking call DownloadString
var location = RetrieveFormatedAddress(51.962146, 7.602304);
string RetrieveFormatedAddress(double lat, double lon)
{
using (WebClient client = new WebClient())
{
string xml = client.DownloadString(String.Format(baseUri, lat, lon));
return ParseXml(xml);
}
}
private static string ParseXml(string xml)
{
var result = XDocument.Parse(xml)
.Descendants("formatted_address")
.FirstOrDefault();
if (result != null)
return result.Value;
else
return "No Address Found";
}
If you want to make it async
var location = await RetrieveFormatedAddressAsync(51.962146, 7.602304);
async Task<string> RetrieveFormatedAddressAsync(double lat,double lon)
{
using(HttpClient client = new HttpClient())
{
string xml = await client.GetStringAsync(String.Format(baseUri,lat,lon));
return ParseXml(xml);
}
}