Using jagged arrays

Question

Consider the following code.

public string[][] CalculateDistance(string origin, string destination)
{
        string[][] result = new string[1][];

        string url = "MyUrl"
        string requesturl = url;
        string content = fileGetContents(requesturl);
        JObject o = JObject.Parse(content);
        result[0] = new string[2];
        result[0][0] = (string)o.SelectToken("routes[0].legs[0].distance.text");
        result[0][1] = (string)o.SelectToken("routes[0].legs[0].duration.text");

        string[][] myArray = new string[2][];
        for (int i = 0; i < result.Length; i++)
        {
            string[] innerArray = result[i];
        }
        return result;
}

I'm trying to return a jagged array which I then use on a ListView in a wpf application. If I use Console.WriteLine(innerArray) inside the for loop I get the correct result displayed. However when displayed in the ListView I get

String[][] Array

Can someone please tell me where I'm going wrong. I've never worked with jagged arrays before so I'm finding it really difficult to figure out what I'm doing wrong.

XMAL Code looks like:

<ListView Name="MyList" HorizontalAlignment="Left" Height="315" Margin="1289,425,-435,0" VerticalAlignment="Top" Width="421">
        <ListView.View>
            <GridView>
                <GridViewColumn Header="Name"
                DisplayMemberBinding="{Binding Time}"
                Width="100"/>
            </GridView>
        </ListView.View>
</ListView>

And the backend to add items to the list I use:

foreach (var items in GetAddress())
{
  MyList.Items.Add(new Distance() { Time = distance.CalculateDistance(items.FromPostCode, items.DestinationPostCode) });
}

Distance Class looks like

public class Distance
{
    public string[][] Time { get; set; }
    //More properties 
}

Show your *WPF* code, please. It doesn't matter, how do you populate an array - sample data will be enough. — Dennis, Oct 21 '15 at 08:32
In code behind you just add array into items collection. Obviously, `ListView` calls `Distance.Time.ToString()` to get visual representation of item. How do you want to display this array? — Dennis, Oct 21 '15 at 08:40
@Dennis In console my array looks like `7.1 mi` and `11 mins` which I want to display on my List, so the first column becomes miles and second becomes mins — Izzy, Oct 21 '15 at 08:45
@M.kazemAkhgary Just mentioned it to Dennis please see my comment — Izzy, Oct 21 '15 at 08:46
@Code ok. then what is Time? thats a column too. you want miles and mins instead of that? — M.kazem Akhgary, Oct 21 '15 at 09:03
@M.kazemAkhgary Time is a property distance class, But yes I want the miles and mins in the column — Izzy, Oct 21 '15 at 09:07

M.kazem Akhgary · Accepted Answer · 2015-10-21T09:25:51.717

First of all change your list view to something like this to do correct data binding. (use your own optional length and properties.)

<ListView x:Name="MyList" Height="299" Width="497">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Miles" Width="100" DisplayMemberBinding="{Binding Miles}"/>
            <GridViewColumn Header="Mins" Width="100" DisplayMemberBinding="{Binding Mins}"/>
        </GridView>
    </ListView.View>
</ListView>

Here is the sample use with jagged array.

string[][] list = new[] {new[] {"Hello", "Bye"}, new[] {"Hey", "Ho"}, new[] {"Yep", "Nope"}};
MyList.ItemsSource = list.Select(x => new {Miles = x[0], Mins = x[1]});

But I dont understand the reason you are using Jagged array. You are already creating 1 length of that. that doesnt make sense. just use a single array with length of 2. If you need this for something else that you have not shown then you must show it then i will update my answer as well. currently i removed unnecessary parts.

public string[] CalculateDistance(string origin, string destination)
{
    string[] result = new string[2];

    string url = "MyUrl"
    string requesturl = url;
    string content = fileGetContents(requesturl);

    JObject o = JObject.Parse(content);

    result[0] = (string)o.SelectToken("routes[0].legs[0].distance.text");
    result[1] = (string)o.SelectToken("routes[0].legs[0].duration.text");

    return result;
}

And then when you want to fill items. Note that you dont need Distance class too. If you only use it for binding properties then just write new {} to create anonymous type instead which works perfect.

foreach (var items in GetAddress())
{
    var d = distance.CalculateDistance(items.FromPostCode, items.DestinationPostCode);
    MyList.Items.Add(new { Miles = d[0], Mins = d[1] });
}

Thanks man, it works perfectly! I change `public string[][]` to `public string[]` as it was giving me an error, so you might want to change that in your answer for future readers. The reason I was using jagged array because I thought i'll bind each item to column as you've done with a single array, I didn't know you could :/ — Izzy, Oct 21 '15 at 09:23

Using jagged arrays

1 Answers1