Sorting with Up and Down icons
4.00/5 (1 vote)
1. First we need to create two variables in ViewState to store current direction and expression:public string CurrentSortExpression { get { if (ViewState["sortExpression"] != null) { return...
1. First we need to create two variables in ViewState to store current direction and expression:
public string CurrentSortExpression
{
get
{
if (ViewState["sortExpression"] != null)
{
return ViewState["sortExpression"].ToString();
}
else
{
ViewState["sortExpression"] = string.Empty;
return string.Empty;
}
}
set
{
ViewState["sortExpression"] = value;
}
}
public string CurrentSortDirection
{
get
{
if (ViewState["sortDirection"] != null)
{
return ViewState["sortDirection"].ToString();
}
return string.Empty;
}
set
{
ViewState["sortDirection"] = value;
}
}
2. Then we have to implement handler to attach sort icons to header rows:
protected void GridViewSortImages(object sender, GridViewRowEventArgs e)
{
GridView senderGridView = (GridView)sender;
Literal space = new Literal();
space.Text = " ";
if (e.Row != null && e.Row.RowType == DataControlRowType.Header)
{
for(int i=0;i<gvusers.columns.count;i++)>
{
TableCell cell = e.Row.Cells[i];
DataControlField column=gvUsers.Columns[i];
if (cell.HasControls())
{
LinkButton button = cell.Controls[0] as LinkButton;
if (button != null)
{
Image image = new Image();
image.ImageUrl = "~/AdminUI/Images/icon-sort_default.gif";
if (CurrentSortExpression==column.SortExpression)
{
if (CurrentSortDirection=="asc")
image.ImageUrl = "~/AdminUI/Images/icon-sort1.gif";
else if (CurrentSortDirection=="desc")
image.ImageUrl = "~/AdminUI/Images/icon-sort2.gif";
}
cell.Controls.Add(image);
}
}
}
}
}
3. Farther let's make some logic in Sorting handler for our GridView:
protected void gvUsers_Sorting(object sender, GridViewSortEventArgs e)
{
if (CurrentSortExpression == e.SortExpression.ToString())
{
if (CurrentSortDirection == "asc")
CurrentSortDirection = "desc";
else
CurrentSortDirection = "asc";
}
else
{
CurrentSortExpression = e.SortExpression.ToString();
CurrentSortDirection = "asc";
}
BindUsers(0, CurrentSortExpression, (CurrentSortDirection == "asc")?true:false);
}
4. And at last lets use GridViewSortImages in RowCreated event:
protected void gvUsers_RowCreated(object sender, GridViewRowEventArgs e)
{
// Some code
GridViewSortImages(sender, e);
}