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WinFormDi/ListViewColumnSorter.cs

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+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;
+
+        // 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;
+        }
+    }
+
+}