小编Kev*_*vin的帖子

运行这行代码时,我收到一个System.NullReferenceException.

// Occurs on this line
if (xDoc.Root.Element("data").Element("forecast").Element("record").Value == "0")
{
    tempnow.Text = xDoc.Root.Element("data").Element("forecast").Element("pop").Value;
}

Xdoc定义在类下面,如果这与它有关.

{
    public partial class MainPage : PhoneApplicationPage
    {

        XDocument xDoc;

这是我试图访问的XML文档,并找到"记录"的值.这也是"Xdoc"所代表的文档,其中包含以下信息.

<data>
  <status>success</status>
  <location>
    <city/>
    <fullName>39.6N, 0.3W - 6miles SW of El Puerto, SP</fullName>
    <localDate>2014-01-30T01:29:23</localDate>
    <localEpoch>1391045363</localEpoch>
    <locationID>GP202368</locationID>
  </location>
  <forecast>
    <record>0</record>
    <utcEpoch>1391040000</utcEpoch>
    <utcDate>2014-01-30T00:00:00</utcDate>
    <maxTempC>15.4</maxTempC>
    <maxTempF>59.7</maxTempF>
    <minTempC>5.2</minTempC>
    <minTempF>41.3</minTempF>
    <fcstDay>1</fcstDay>
    <dayLength>10:07</dayLength>
    <sunriseHHMMLocal>8:11am</sunriseHHMMLocal>
    <sunsetHHMMLocal>6:18pm</sunsetHHMMLocal>
    <nightLength/>
    <moonriseHHMMLocal/>
    <moonsetHHMMLocal/>
    <moonphase/>
    <moonillum/>
    <moonicon/>
    <pop>19</pop>
    <uv_index>2</uv_index>
    <gustC>30</gustC>
    <gustF>19</gustF>
    <heatindexC>-999.99</heatindexC>
    <heatindexF>-999.99</heatindexF>
    <icon>partly-cloudy-sm.png</icon>
    <iconBase>partly-cloudy</iconBase>
    <iconLg>partly-cloudy.png</iconLg>
    <prcpC>0</prcpC>
    <prcpF>0</prcpF>
    <rh>33</rh>
    <skyCover>8</skyCover>
    <snowC>0</snowC>
    <snowF>0</snowF>
    <wdir>NW</wdir>
    <windchillC>-999.99</windchillC>
    <windchillF>-999.99</windchillF> …

非常困惑于为什么"c"在我编程改变时不会改变.没什么可说的,可能是一个愚蠢的错误,但无法弄明白......

//declared OUTSIDE of the method.        
private string c = "1";

private void expanded(object sender, GestureEventArgs e)
{
    if (debug2.Text == "Temp")
    {
        if (c == "1")
        {
            c = "2";
            ((Storyboard)this.Resources["_in"]).Begin();
        }
        if (c == "2")
        {
            c = "1";
            ((Storyboard)this.Resources["_in1"]).Begin();
        }
    }
}

我有一个"1 + 1"的字符串.当我对它进行int.Parse时,输出"11".有没有办法让它找到总和？

代码:(设置为IsolatedStorageSettings,即1 + 1字符串)

MessageBox.Show(int.Parse(settings["favoritesnum"].ToString()).ToString());