CODEWITHSUNDEEP
c#arraysmultidimensional-array
Rhys
Rhys

Reputation: 2877

How to setup error checking for arrays?

I am using HTML agility pack and parsing to an array.

The information I am parsing changes and when it changes below a certain level I get unhandled exceptions because I am trying to bind the an element [][] that isn't there.

How would I setup error checking to make sure if the array isn't there it wouldn't throw an Unhandled expection?

Eg... If I use the below code and there is no [2][1] then I get an exception, but the html changes so It needs to cope with null dor non existant arrays elements

    //first line
    textBlock1.Text = node[0][0];
    textBlock2.Text = node[0][1];
    textBlock3.Text = node[0][2];

    //first line
    textBlock4.Text = node[1][0];
    textBlock5.Text = node[1][1];
    textBlock6.Text = node[1][2];

    //first line
    textBlock7.Text = node[2][0];
    textBlock8.Text = node[2][1];
    textBlock9.Text = node[2][2];

Array is from this code:

void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
    var html = e.Result;

    var doc = new HtmlDocument();
    doc.LoadHtml(html);

    var list = doc.DocumentNode.Descendants("div").ToList();

    var node = doc.DocumentNode.Descendants("table")
         .FirstOrDefault(x => x.Id == "departures")
        .Element("tbody")
         .Elements("tr")
          .Select(tr => tr.Elements("td").Select(td => td.InnerText).ToArray())
          .ToArray();

Upvotes: 0

Views: 108

Answers (1)

Amittai Shapira
Amittai Shapira

Reputation: 3827

You can check length for both dimensions, e.g. 

if (node.Length > 2)
{
   //first line
   if (node[2].Length > 0)
   {
      textBlock7.Text = node[2][0];
   }
}

Upvotes: 1

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