/// <summary>
/// Executes when the control is initialized completely the first time through. Runs only once.
/// </summary>
/// <param name="e"></param>
protected override void OnInitialized(EventArgs e)
{
// add the event handler to the GridViewColumnHeader. This strongly ties this ListView to a GridView.
this.AddHandler(GridViewColumnHeader.ClickEvent, new RoutedEventHandler(GridViewColumnHeaderClickedHandler));
// cast the ListView's View to a GridView
GridView gridView = this.View as GridView;
if (gridView != null)
{
// determine which column is marked as IsDefaultSortColumn. Stops on the first column marked this way.
SortableGridViewColumn sortableGridViewColumn = null;
foreach (GridViewColumn gridViewColumn in gridView.Columns)
{
sortableGridViewColumn = gridViewColumn as SortableGridViewColumn;
if (sortableGridViewColumn != null)
{
if (sortableGridViewColumn.IsDefaultSortColumn)
{
break;
}
sortableGridViewColumn = null;
}
}
// if the default sort column is defined, sort the data and then update the templates as necessary.
if (sortableGridViewColumn != null)
{
lastSortedOnColumn = sortableGridViewColumn;
Sort(sortableGridViewColumn.SortPropertyName, ListSortDirection.Ascending);
if (!String.IsNullOrEmpty(this.ColumnHeaderSortedAscendingTemplate))
{
sortableGridViewColumn.HeaderTemplate = this.TryFindResource(ColumnHeaderSortedAscendingTemplate) as DataTemplate;
}
this.SelectedIndex = 0;
}
}
base.OnInitialized(e);
}
/// <summary>
/// Event Handler for the ColumnHeader Click Event.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void GridViewColumnHeaderClickedHandler(object sender, RoutedEventArgs e)
{
GridViewColumnHeader headerClicked = e.OriginalSource as GridViewColumnHeader;
// ensure that we clicked on the column header and not the padding that's added to fill the space.
if (headerClicked != null && headerClicked.Role != GridViewColumnHeaderRole.Padding)
{
// attempt to cast to the sortableGridViewColumn object.
SortableGridViewColumn sortableGridViewColumn = (headerClicked.Column) as SortableGridViewColumn;
// ensure that the column header is the correct type and a sort property has been set.
if (sortableGridViewColumn != null && !String.IsNullOrEmpty(sortableGridViewColumn.SortPropertyName))
{
ListSortDirection direction;
bool newSortColumn = false;
// determine if this is a new sort, or a switch in sort direction.
if (lastSortedOnColumn == null ||
String.IsNullOrEmpty(lastSortedOnColumn.SortPropertyName) ||
!String.Equals(sortableGridViewColumn.SortPropertyName, lastSortedOnColumn.SortPropertyName, StringComparison.InvariantCultureIgnoreCase))
{
newSortColumn = true;
direction = ListSortDirection.Ascending;
}
else
{
if (lastDirection == ListSortDirection.Ascending)
{
direction = ListSortDirection.Descending;
}
else
{
direction = ListSortDirection.Ascending;
}
}
// get the sort property name from the column's information.
string sortPropertyName = sortableGridViewColumn.SortPropertyName;
List <object> sel = new List <object>();
foreach (object s in SelectedItems)
{
sel.Add(s);
}
// Sort the data.
Sort(sortPropertyName, direction);
this.SelectedItems.Clear();
foreach (object s in sel)
{
this.SelectedItems.Add(s);
}
if (direction == ListSortDirection.Ascending)
{
if (!String.IsNullOrEmpty(this.ColumnHeaderSortedAscendingTemplate))
{
sortableGridViewColumn.HeaderTemplate = this.TryFindResource(ColumnHeaderSortedAscendingTemplate) as DataTemplate;
}
else
{
sortableGridViewColumn.HeaderTemplate = null;
}
}
else
{
if (!String.IsNullOrEmpty(this.ColumnHeaderSortedDescendingTemplate))
{
sortableGridViewColumn.HeaderTemplate = this.TryFindResource(ColumnHeaderSortedDescendingTemplate) as DataTemplate;
}
else
{
sortableGridViewColumn.HeaderTemplate = null;
}
}
// Remove arrow from previously sorted header
if (newSortColumn && lastSortedOnColumn != null)
{
if (!String.IsNullOrEmpty(this.ColumnHeaderNotSortedTemplate))
{
lastSortedOnColumn.HeaderTemplate = this.TryFindResource(ColumnHeaderNotSortedTemplate) as DataTemplate;
}
else
{
lastSortedOnColumn.HeaderTemplate = null;
}
}
lastSortedOnColumn = sortableGridViewColumn;
}
}
}
