Row Numbers
By default, RadGridView displays a current row indicator in the row header represented by an arrow image. A common requirement is to display the row number in the row header as well. This can be easily achieved by handling the ViewCellFormatting event. You can find below a sample code snippet.
Figure 1: Row numbers
Handling the ViewCellFormatting event
private void radGridView1_ViewCellFormatting(object sender, CellFormattingEventArgs e)
{
if (e.CellElement is GridRowHeaderCellElement && e.Row is GridViewDataRowInfo)
{
e.CellElement.Text = (e.CellElement.RowIndex + 1).ToString();
e.CellElement.TextImageRelation = TextImageRelation.ImageBeforeText;
}
else
{
e.CellElement.ResetValue(LightVisualElement.TextImageRelationProperty, ValueResetFlags.Local);
}
}
Private Sub radGridView1_ViewCellFormatting(sender As Object, e As CellFormattingEventArgs)
If TypeOf e.CellElement Is GridRowHeaderCellElement AndAlso TypeOf e.Row Is GridViewDataRowInfo Then
e.CellElement.Text = (e.CellElement.RowIndex + 1).ToString()
e.CellElement.TextImageRelation = TextImageRelation.ImageBeforeText
Else
e.CellElement.ResetValue(LightVisualElement.TextImageRelationProperty, ValueResetFlags.Local)
End If
End Sub
The RowIndex property internally uses the ChildRows collection. This collection returns the data rows that are currently represented by RadGridView in the order in which they appear. The collection is modified every time a data operation (grouping, sorting, filtering) occurs. Similar to filtering, sorting and grouping, the ChildRows collection is affected by the paging as well and it contains only the records on the current page. A common scenario is to access the real row index when the paging is enabled in the order the items appear in the grid.
The RadGridView.MasterTemplate.DataView.Indexer offers the Items collection which contains all the rows in the order in which they appear in the grid. The collection is affected every time a data operation like grouping, sorting, filtering occurs. You can use it to extract the correct index when moving through the pages:
private void radGridView1_ViewCellFormatting(object sender, Telerik.WinControls.UI.CellFormattingEventArgs e)
{
if (e.CellElement is GridRowHeaderCellElement && e.Row is GridViewDataRowInfo)
{
GridDataView dataView = this.radGridView1.MasterTemplate.DataView as GridDataView;
e.CellElement.Text = (dataView.Indexer.Items.IndexOf(e.Row) + 1).ToString();
e.CellElement.TextImageRelation = TextImageRelation.ImageBeforeText;
}
else
{
e.CellElement.ResetValue(LightVisualElement.TextImageRelationProperty, ValueResetFlags.Local);
}
}
Private Sub radGridView1_ViewCellFormatting(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.CellFormattingEventArgs)
If TypeOf e.CellElement Is GridRowHeaderCellElement AndAlso TypeOf e.Row Is GridViewDataRowInfo Then
Dim dataView As GridDataView = TryCast(Me.radGridView1.MasterTemplate.DataView, GridDataView)
e.CellElement.Text = (dataView.Indexer.Items.IndexOf(e.Row) + 1).ToString()
e.CellElement.TextImageRelation = TextImageRelation.ImageBeforeText
Else
e.CellElement.ResetValue(LightVisualElement.TextImageRelationProperty, ValueResetFlags.Local)
End If
End Sub
It is necessary to increase the header row's width in order to have enough space to display the row number and the current row indicator. This can be accomplished by setting the TableElement.RowHeaderColumnWidth property.
Adjust the RowHeaderColumnWidth
this.radGridView1.TableElement.RowHeaderColumnWidth = 50;
Me.RadGridView1.TableElement.RowHeaderColumnWidth = 50