How to grab second occurring name from xml api data with C#

Question

I'm trying to grab the high and low from this api, I am able to get the High, but can't figure out what to do to get the Low, which is the second occurring item with the name "fahrenheit", how could I do this using the same method I used for getting the High?

if (xmlForecast.Name == "fahrenheit" && i == 0)
{
   i++;
   xmlHigh = xmlForecast.ReadString();
}

Answer 1

Since you want solution using XML response, here it is:

First, you'll need to create classes which will represent XML response.

[XmlRoot("response")]
public class Response
{
    [XmlElement("version")]
    public string Version { get; set; }
    [XmlElement("termsofService")]
    public string TermsOfService { get; set; }
    [XmlElement("features")]
    public Features Features { get; set; }
    [XmlElement("forecast")]
    public Forecast Forecast { get; set; }
}

public class Features
{
    [XmlElement("forecast")]
    public int Forecast { get; set; }
}

public class Forecast
{
    [XmlElement("txt_forecast")]
    public TxtForecast TxtForecast { get; set; }
    [XmlElement("simpleforecast")]
    public SimpleForecast SimpleForecast { get; set; }
}

public class TxtForecast
{
    [XmlElement("date")]
    public string Date { get; set; }
    [XmlArray("forecastdays")]
    [XmlArrayItem("forecastday")]
    public List<ForecastDay> ForecastDays { get; set; }
}

public class ForecastDay
{
    [XmlElement("period")]
    public int Period { get; set; }
    [XmlElement("icon")]
    public string Icon { get; set; }
    [XmlElement("icon_url")]
    public string IconUrl { get; set; }
    [XmlElement("title")]
    public string Title { get; set; }
    [XmlElement("fcttext")]
    public string FctText { get; set; }
    [XmlElement("fcttext_metric")]
    public string FctTextMetric { get; set; }
    [XmlElement("pop")]
    public string Pop { get; set; }
}


public class SimpleForecast
{
    [XmlArray("forecastdays")]
    [XmlArrayItem("forecastday")]
    public List<ForecastDay2> ForecastDays { get; set; }
}

public class ForecastDay2
{
    [XmlElement("date")]
    public Date Date { get; set; }
    [XmlElement("period")]
    public int Period { get; set; }
    [XmlElement("high")]
    public High High { get; set; }
    [XmlElement("low")]
    public Low Low { get; set; }
    [XmlElement("conditions")]
    public string Conditions { get; set; }
    [XmlElement("icon")]
    public string Icon { get; set; }
    [XmlElement("icon_url")]
    public string IconUrl { get; set; }
    [XmlElement("skyicon")]
    public string SkyIcon { get; set; }
    [XmlElement("pop")]
    public int Pop { get; set; }
    [XmlElement("qpf_allday")]
    public QpfAllday QpfAllDay { get; set; }
    [XmlElement("qpf_day")]
    public QpfDay QpfDay { get; set; }
    [XmlElement("qpf_night")]
    public QpfNight QpfNight { get; set; }
    [XmlElement("snow_allday")]
    public SnowAllday SnowAllday { get; set; }
    [XmlElement("snow_day")]
    public SnowDay SnowDay { get; set; }
    [XmlElement("snow_night")]
    public SnowNight SnowNight { get; set; }
    [XmlElement("maxwind")]
    public MaxWind MaxWind { get; set; }
    [XmlElement("avewind")]
    public AveWind AveWind { get; set; }
    [XmlElement("avehumidity")]
    public int AveHumidity { get; set; }
    [XmlElement("maxhumidity")]
    public int MaxHumidity { get; set; }
    [XmlElement("minhumidity")]
    public int MinHumidity { get; set; }
}

public class Date
{
    [XmlElement("epoch")]
    public string Epoch { get; set; }
    [XmlElement("pretty")]
    public string Pretty { get; set; }
    [XmlElement("day")]
    public int Day { get; set; }
    [XmlElement("month")]
    public int Month { get; set; }
    [XmlElement("year")]
    public int Year { get; set; }
    [XmlElement("yday")]
    public int Yesterday { get; set; }
    [XmlElement("hour")]
    public int Hour { get; set; }
    [XmlElement("min")]
    public string Min { get; set; }
    [XmlElement("sec")]
    public int Sec { get; set; }
    [XmlElement("isdst")]
    public string Isdst { get; set; }
    [XmlElement("monthname")]
    public string MonthName { get; set; }
    [XmlElement("monthname_short")]
    public string MonthNameShort { get; set; }
    [XmlElement("weekday_short")]
    public string WeekdayShort { get; set; }
    [XmlElement("weekday")]
    public string Weekday { get; set; }
    [XmlElement("ampm")]
    public string AmPM { get; set; }
    [XmlElement("tz_short")]
    public string TzShort { get; set; }
    [XmlElement("tz_long")]
    public string TzLong { get; set; }
}

public class High
{
    [XmlElement("fahrenheit")]
    public string Fahrenheit { get; set; }
    [XmlElement("celsius")]
    public string Celsius { get; set; }
}

public class Low
{
    [XmlElement("fahrenheit")]
    public string Fahrenheit { get; set; }
    [XmlElement("celsius")]
    public string Celsius { get; set; }
}

public class QpfAllday
{
    [XmlElement("@in")]
    public double Inches { get; set; }
    [XmlElement("mm")]
    public int Milimeters { get; set; }
}

public class QpfDay
{
    [XmlElement("@in")]
    public double Inches { get; set; }
    [XmlElement("mm")]
    public int Milimeters { get; set; }
}

public class QpfNight
{
    [XmlElement("@in")]
    public double Inches { get; set; }
    [XmlElement("mm")]
    public int Milimeters { get; set; }
}

public class SnowAllday
{
    [XmlElement("@in")]
    public double Inches { get; set; }
    [XmlElement("cm")]
    public double Centimeters { get; set; }
}

public class SnowDay
{
    [XmlElement("@in")]
    public double Inches { get; set; }
    [XmlElement("cm")]
    public double Centimeters { get; set; }
}

public class SnowNight
{
    [XmlElement("@in")]
    public double Inches { get; set; }
    [XmlElement("cm")]
    public double Centimeters { get; set; }
}

public class MaxWind
{
    [XmlElement("mph")]
    public int Mph { get; set; }
    [XmlElement("kph")]
    public int Kph { get; set; }
    [XmlElement("dir")]
    public string Direction { get; set; }
    [XmlElement("degrees")]
    public int Degrees { get; set; }
}

public class AveWind
{
    [XmlElement("mph")]
    public int Mph { get; set; }
    [XmlElement("kph")]
    public int Kph { get; set; }
    [XmlElement("dir")]
    public string Direction { get; set; }
    [XmlElement("degrees")]
    public int Degrees { get; set; }
}

Secondly, you need to deserialize XML into Response

using (HttpClient client = new HttpClient())
{
    using (var stream = await client.GetStreamAsync("http://api.wunderground.com/api/ea4bb7e7839782da/forecast/q/CA/San_Francisco.xml"))
    {
        var serializer = new XmlSerializer(typeof(Response));
        var response = (Response)serializer.Deserialize(stream);

        var simpleForecast = response.Forecast.SimpleForecast;
        var forecastDays = simpleForecast.ForecastDays;
        var latestForecastDay = forecastDays.Last();
        var latestHighFahrenheit = latestForecastDay.High.Fahrenheit;
        var latestLowFahrenheit = latestForecastDay.Low.Fahrenheit;
    }
}

I am using XmlSerializer but you can also use DataContractSerializer which is newer. If you decide to use DataContractSerializer keep in mind that you'll need to replace XmlElement attributes with DataContract and DataMember.

Note: I've intentionally added few unnecessary steps and variable declarations, so you can see clearly what's going on here.