c# - XML Document not loading from web URL - NullReferenceException -
this question has answer here:
- what nullreferenceexception, , how fix it? 32 answers
i want load weather information openweathermap.org's api xml document.
public weather() { /* generates custom weather url */ this.urlstub= @"http://api.openweathermap.org/data/2.5/forecast/daily?q="; this.location = "glasgow,uk"; this.apikey = "&appid=6911e84eacde075fdbdfaf05b9a2aaf5"; this.mode = "&mode=xml"; this.forecastweatherurl = urlstub + location + apikey + mode; } public bool loadxml() { /* loads xml info web */ try { this.forecastweatherxml.loadxml(forecastweatherurl); return true; } catch (system.nullreferenceexception ex) { console.out.writeline("error loading xml doc\n" + ex.stacktrace); return false; } } private void loadweatherbtn_click(object sender, eventargs e) { weather weather = new weather(); console.out.writeline(weather); // prints generated xml url if (weather.loadxml()) { console.out.writeline("xml loaded"); } the loadweatherbtn_click method part of different class. output is:
> weather url: http://api.openweathermap.org/data/2.5/forecast/daily?q=glasgow,uk&appid=6911e84eacde075fdbdfaf05b9a2aaf5&mode=xml error loading xml doc @ al_fresgow.weather.loadxml() in c:\rootdirectory\appname\appname\weather.cs:line 163 the generated url shown in output works correctly why isn't loading?? program need wait load first (calculation time xml doc 0.0085 secs)?
i have assume type of this.forecastweatherxml xmldocument, though posted code not show declaration.
based on that, primary problem use of loadxml() method expects xml string input. msdn
try using method load() loads xml document specified url:
this.forecastweatherxml.load(forecastweatherurl);
Comments
Post a Comment