ListView column highest value

Question

I don't need to sort listView I only need to get highest value from column, all values in that column are numbers.It would be nice if I could cast it to IEnumerable<int> somehow then I could use LINQ.

Update

My existing code: DrawArray is array with random numbers.I need to get max value of index.ToString() column without creating another list or array.

for (int i = 0; i < Rounds; i++)
{
ListViewItem lvItem = new ListViewItem(i.ToString());

lvItem.SubItems.Add(new ListViewItem.ListViewSubItem(lvItem, index.ToString()));

int[] DrawArray = Draw(DrawsPerRound, RoundSize);

lvItem.SubItems.Add(new ListViewItem.ListViewSubItem(lvItem, DrawArray.Aggregate("", (s, t) => s + ", " + t.ToString()).TrimStart(new char[] { ',' })));

lvItem.SubItems.Add(new ListViewItem.ListViewSubItem(lvItem, "No"));

lvItem.BackColor = Color.PaleVioletRed;

listView1.Items.Add(lvItem);
}

You can use methods in this link: http://stackoverflow.com/questions/914109/how-to-use-linq-to-select-object-with-minimum-or-maximum-property-value — Josh, May 17 '12 at 18:40

bitoshi.n · Answer 1 · 2012-05-17T19:52:44.907

1

ListView.Items is ListViewItemCollection inherit of IList, ICollection, IEnumerable

By linq, you can get what you want.

System.Nullable<int> max = (
              from m in listView1.Items.Cast<ListViewItem>() 
              select int.ParseInt(m.SubItems[0].Text)).Max();

edited May 17 '12 at 19:52

answered May 17 '12 at 18:29

bitoshi.n

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Lose the 'var' in your query which souldn't be there, and you will get Could not find an implementation of the query pattern for source type 'System.Windows.Forms.ListView.ListViewItemCollection'. 'Select' not found. Consider explicitly specifying the type of the range variable 'm'. – formatc May 17 '12 at 18:48
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You need to explicitly specify (cast to) the type of the variable m whenever the compiler can't infer its actual type. Therefore, listview1.Items.Cast() should solve the problem. – Daniel May 17 '12 at 19:36

Tim S. · Accepted Answer · 2012-05-17T19:41:39.207

1

Might be missing some casts or something, and it is a bit ugly, but here's an idea:

var max = listView1.Items.Cast<ListViewItem>().Max(x => int.Parse(x.SubItems[0].Text));

This uses LINQ, so make sure you have using System.Linq; in your file and are using .NET >= 3.5.

edited May 17 '12 at 19:41

answered May 17 '12 at 18:31

Tim S.

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Well I tried but I can't acess Max directly I assume it has to be casted first. – formatc May 17 '12 at 18:35
1

listView1.Items.Cast().Max(x => int.Parse(x.SubItems[0].Text)); – Daniel May 17 '12 at 19:28
Thanks @DanielVlasceanu, I'll put that `Cast` into my answer. – Tim S. May 17 '12 at 19:41

ListView column highest value

2 Answers2