示例#1
0
        /// <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 = 0;
            ListViewItem listviewX, listviewY;

            // Cast the objects to be compared to ListViewItem objects
            listviewX = (ListViewItem)x;
            listviewY = (ListViewItem)y;

            ListView listViewMain = listviewX.ListView;

            // Calculate correct return value based on object comparison
            if (listViewMain != null && (listViewMain.Sorting != SortOrder.Ascending && listViewMain.Sorting != SortOrder.Descending))
            {
                // Return '0' to indicate they are equal
                return(compareResult);
            }

            if (sortModifier.Equals(SortModifiers.SortByText) || ColumnToSort > 0)
            {
                // Compare the two items

                if (listviewX.SubItems.Count <= ColumnToSort && listviewY.SubItems.Count <= ColumnToSort)
                {
                    compareResult = ObjectCompare.Compare(null, null);
                }
                else if (listviewX.SubItems.Count <= ColumnToSort && listviewY.SubItems.Count > ColumnToSort)
                {
                    compareResult = ObjectCompare.Compare(null, listviewY.SubItems[ColumnToSort].Text.Trim());
                }
                else if (listviewX.SubItems.Count > ColumnToSort && listviewY.SubItems.Count <= ColumnToSort)
                {
                    compareResult = ObjectCompare.Compare(listviewX.SubItems[ColumnToSort].Text.Trim(), null);
                }
                else
                {
                    compareResult = ObjectCompare.Compare(listviewX.SubItems[ColumnToSort].Text.Trim(), listviewY.SubItems[ColumnToSort].Text.Trim());
                }
            }
            else
            {
                switch (sortModifier)
                {
                case SortModifiers.SortByCheckbox:
                    compareResult = CheckBoxObjectCompare.Compare(x, y);
                    break;

                case SortModifiers.SortByImage:
                    compareResult = TextObjectCompare.Compare(x, y);
                    break;

                case SortModifiers.SortCustom:
                    compareResult = CustomCompare.Compare(x, y);
                    break;

                default:
                    compareResult = TextObjectCompare.Compare(x, y);
                    break;
                }
            }

            // 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);
            }
        }