GridView Multicolumn sorting
The ASP.NET GridView control is the successor to the v1.x DataGrid, adding the ability to take advantage of specific capabilities of ASP.NET data source controls. Whereas the v1.x DataGrid required a page developer to write custom code to handle simple operations such as paging, sorting, editing or deleting data, the GridView control can automatically handle these operations provided its bound data source control supports these capabilities. The GridView also offers some functionality improvements over the DataGrid, such as the ability to define multiple primary key fields, and some UI customization improvements, such as new field types and templating options. It also exposes a new model for page developers to handle or cancel events. Read more..
GridView's built-in sorting can be enabled by setting a data source and AllowSorting property to true. Click on column header to sort based on the SortExpression specified in the Gridview column. However, Gridview does not support multi column sorting which is required in day to day application.
So here is how I tried to create one-
Create a custom control that will inherit from gridview
public class MCNGridView : GridView
Create properties to enable/disable multicolumn sorting
bool _ShowSortSequence = false;
bool _EnableMultiColumnSorting = false;
string _SortAscImageUrl = string.Empty;
string _SortDescImageUrl = string.Empty;
#region Properties
/// <summary>
/// Enable/Disable MultiColumn Sorting.
/// </summary>
[
Description("Sorting On more than one column is enabled or not"),
Category("Behavior"),
DefaultValue("false"),
]
public bool EnableMultiColumnSorting
{
get { return _EnableMultiColumnSorting; }
set { AllowSorting = true; _EnableMultiColumnSorting = value; }
}
/// <summary>
/// Enable/Disable Sort Sequence visibility.
/// </summary>
[
Description("Show Sort Sequence or not"),
Category("Behavior"),
DefaultValue("false"),
]
public bool ShowSortSequence
{
get { return _ShowSortSequence; }
set { _ShowSortSequence = value; }
}
/// <summary>
/// Get/Set Image for displaying Ascending Sort order.
/// </summary>
[
Description("Image to display for Ascending Sort"),
Category("Misc"),
Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor)),
DefaultValue(""),
]
public string SortAscImageUrl
{
get { return _SortAscImageUrl; }
set { _SortAscImageUrl = value; }
}
/// <summary>
/// Get/Set Image for displaying Descending Sort order.
/// </summary>
[
Description("Image to display for Descending Sort"),
Category("Misc"),
Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor)),
DefaultValue(""),
]
public string SortDescImageUrl
{
get { return _SortDescImageUrl; }
set { _SortDescImageUrl = value; }
}
Override Gridview OnSorting event
To get the custom sort expression
protected override void OnSorting(GridViewSortEventArgs e)
{
if (EnableMultiColumnSorting)
e.SortExpression = GetSortExpression(e);
base.OnSorting(e);
}
Override Gridview OnRowCreated event
To show the sort direction image and sort sequence
protected override void OnRowCreated(GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
if (SortExpression != String.Empty)
ShowSortOrderImages(SortExpression, e.Row);
}
base.OnRowCreated(e);
}
Other protected methods
/// <summary>
/// Get Sort Expression from existing Grid View Sort Expression
/// </summary>
protected string GetSortExpression(GridViewSortEventArgs e)
{
string[] sortColumns = null;
string sortAttribute = SortExpression;
if (sortAttribute != String.Empty)
{
sortColumns = sortAttribute.Split(",".ToCharArray());
}
if (sortAttribute.IndexOf(e.SortExpression) > 0 || sortAttribute.StartsWith(e.SortExpression))
sortAttribute = UpdateSortExpression(sortColumns, e.SortExpression);
else
sortAttribute += String.Concat(",", e.SortExpression, " ASC ");
return sortAttribute.TrimStart(",".ToCharArray()).TrimEnd(",".ToCharArray());
Muhammad Shariq KhanPosted Jul 20, 2010, 9:54 AM
I am trying your code by using dataset. On page load it displays the data properly and when we click on any field for sorting, it gives the exception "The GridView 'MCNGridView1' fired event Sorting which wasn't handled." Why it is happening so.
adil umairPosted Oct 19, 2009, 6:24 AM
Best for those who are looking for extending GridView.
STEVE PEGGeditedPosted Sep 22, 2009, 2:50 PMEdited Sep 22, 2009, 2:51 PM
Looks great, but I can only get it to filter 1 column, the others don't change when the filters are applied. Any thoughts on what I'm doing wrong?