Made minor changes to the article here to accommodate sorting of both string and numeric values in ListView.
Form1.cs contains
using System;
using System.Windows.Forms;
namespace ListView
{
public partial class Form1 : Form
{
Random rnd = new Random();
private ListViewColumnSorter lvwColumnSorter;
public Form1()
{
InitializeComponent();
// Create an instance of a ListView column sorter and assign it to the ListView control.
lvwColumnSorter = new ListViewColumnSorter();
this.listView1.ListViewItemSorter = lvwColumnSorter;
InitListView();
}
private void InitListView()
{
listView1.View = View.Details;
listView1.GridLines = true;
listView1.FullRowSelect = true;
//Add column header
listView1.Columns.Add("Name", 100);
listView1.Columns.Add("Price", 70);
listView1.Columns.Add("Trend", 70);
for (int i = 0; i < 10; i++)
{
listView1.Items.Add(AddToList("Name" + i.ToString(), rnd.Next(1, 100).ToString(), rnd.Next(1, 100).ToString()));
}
}
private ListViewItem AddToList(string name, string price, string trend)
{
string[] array = new string[3];
array[0] = name;
array[1] = price;
array[2] = trend;
return (new ListViewItem(array));
}
private void listView1_ColumnClick(object sender, ColumnClickEventArgs e)
{
// Determine if clicked column is already the column that is being sorted.
if (e.Column == lvwColumnSorter.SortColumn)
{
// Reverse the current sort direction for this column.
if (lvwColumnSorter.Order == SortOrder.Ascending)
{
lvwColumnSorter.Order = SortOrder.Descending;
}
else
{
lvwColumnSorter.Order = SortOrder.Ascending;
}
}
else
{
// Set the column number that is to be sorted; default to ascending.
lvwColumnSorter.SortColumn = e.Column;
lvwColumnSorter.Order = SortOrder.Ascending;
}
// Perform the sort with these new sort options.
this.listView1.Sort();
}
}
}
ListViewColumnSorter.cs contains
using System;
using System.Collections;
using System.Windows.Forms;
/// <summary>
/// This class is an implementation of the 'IComparer' interface.
/// </summary>
public class ListViewColumnSorter : IComparer
{
/// <summary>
/// Specifies the column to be sorted
/// </summary>
private int ColumnToSort;
/// <summary>
/// Specifies the order in which to sort (i.e. 'Ascending').
/// </summary>
private SortOrder OrderOfSort;
/// <summary>
/// Case insensitive comparer object
/// </summary>
private CaseInsensitiveComparer ObjectCompare;
/// <summary>
/// Class constructor. Initializes various elements
/// </summary>
public ListViewColumnSorter()
{
// Initialize the column to '0'
ColumnToSort = 0;
// Initialize the sort order to 'none'
OrderOfSort = SortOrder.None;
// Initialize the CaseInsensitiveComparer object
ObjectCompare = new CaseInsensitiveComparer();
}
/// <summary>
/// This method is inherited from the IComparer interface. It compares the two objects passed using a case insensitive comparison.
/// </summary>
/// <param name="x">First object to be compared</param>
/// <param name="y">Second object to be compared</param>
/// <returns>The result of the comparison. "0" if equal, negative if 'x' is less than 'y' and positive if 'x' is greater than 'y'</returns>
public int Compare(object x, object y)
{
int compareResult;
ListViewItem listviewX, listviewY;
// Cast the objects to be compared to ListViewItem objects
listviewX = (ListViewItem)x;
listviewY = (ListViewItem)y;
decimal num = 0;
if (decimal.TryParse(listviewX.SubItems[ColumnToSort].Text, out num))
{
compareResult = decimal.Compare(num, Convert.ToDecimal(listviewY.SubItems[ColumnToSort].Text));
}
else
{
// Compare the two items
compareResult = ObjectCompare.Compare(listviewX.SubItems[ColumnToSort].Text, listviewY.SubItems[ColumnToSort].Text);
}
// Calculate correct return value based on object comparison
if (OrderOfSort == SortOrder.Ascending)
{
// Ascending sort is selected, return normal result of compare operation
return compareResult;
}
else if (OrderOfSort == SortOrder.Descending)
{
// Descending sort is selected, return negative result of compare operation
return (-compareResult);
}
else
{
// Return '0' to indicate they are equal
return 0;
}
}
/// <summary>
/// Gets or sets the number of the column to which to apply the sorting operation (Defaults to '0').
/// </summary>
public int SortColumn
{
set
{
ColumnToSort = value;
}
get
{
return ColumnToSort;
}
}
/// <summary>
/// Gets or sets the order of sorting to apply (for example, 'Ascending' or 'Descending').
/// </summary>
public SortOrder Order
{
set
{
OrderOfSort = value;
}
get
{
return OrderOfSort;
}
}
}