Select first row after sort

[Charles Guthrie]

I'm loading data into a GridView and then programatically applying a multi-column sort.  I'd like to place the user on the first row of the sorted results when the grid opens.  The code:

this.gridChanges.Rows[0].IsSelected = true;

Seems to place the user at the first row of the unsorted data.  How you I place them at the first row of the sorted data?

[Jack]

Hi Charles Guthrie,

You should use the IsCurrent property instead. The IsSelected property indicates that the specified row is selected. This is useful when RadGridView is in multi-row select mode. Should you have any other questions, I will be glad to help.

Regards,
Jack
the Telerik team

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[Brian Peters]

Hi,
I am using RadControls for WinForms Q1 2011 with the following code and the first row in the grid is not the one selected, the 19th row is (after the sorting).
How do I get the first row in the grid to be current and selected after the sorting logic is applied.

With grdPermissionItems2

 

    .DataSource = Nothing

    .ClearSelection()

    .DataSource = dsData.Tables(0)

    .Visible = True

 

    .AllowAddNewRow = False

    .AllowDeleteRow = False

    .AllowEditRow = False

    .EnableCustomGrouping = False

    .EnableGrouping = False

    .EnableSorting = True

 

    .Columns(1).Sort(Telerik.WinControls.UI.RadSortOrder.Ascending, False)

 

    .Rows(0).IsCurrent = True

 

End With

Thanks in advance.


[Jack]

Hi Brian Peters,

The Rows collection contains all rows in the same order they are ordered in the underlying data source. You should use the ChildRows collection to access the sorted rows. Here is a sample:

.ChildRows(0).IsCurrent = True

I hope this helps.
 
Kind regards,
Jack
the Telerik team

[Alwin]

Hi,

i thought

RadGridView1.GridNavigator.SelectFirstRow();

should do everything needed to select the first visible row, but it seems that first row of Rows is selected.

Is there any other BuildIn method to select the first ChildRow?



Best regards



Alwin

[Dess | Tech Support Engineer, Principal]

Hello Alwin,

Thank you for contacting Telerik Support.

If I understand your requirement correctly, you are trying to select the first row after sorting is performed. For this purpose, you may use the SortChanged event and perform selection via the GridNavigator as you mentioned:

private void Form1_Load(object sender, EventArgs e)
{
    this.employeesTableAdapter.Fill(this.nwindDataSet.Employees);

    radGridView1.SortChanged += radGridView1_SortChanged;
}

private void radGridView1_SortChanged(object sender, GridViewCollectionChangedEventArgs e)
{
   radGridView1.GridNavigator.SelectFirstRow();
}

If it is not the exact requirement, please specify more details about the expected behavior.

I hope this information helps. Should you have further questions, I would be glad to help.

Regards,
Desislava
Telerik

[Alwin]

Hello Desislava,

after reading this thread i changed to ChildRows[0], because SelectFirstRow didn't worked as expected.

For testing your sample i switched back to SelectFirstRow, and it also works as expected...



So everythings works fine... crazy...



Best regards

Alwin

[Dess | Tech Support Engineer, Principal]

Hello Alwin,

Thank you for getting back to me.

I am glad that the issue you were facing is now resolved. If you encounter again unexpected behavior of GridNavigator.SelectFirstRow(), we would really appreciate your sample project, successfully reproducing the issue. Thus, we would be able to investigate the case.

Please do not hesitate to contact us if you have any additional questions.

Regards,
Desislava
Telerik

[Jeffrey]

Hi,
This worked for me in a way but the performance slowed down a lot when compared to when I didn't use this to select first row. Seems like it takes 3-4x longer now.

Try
           If RDLDataType.Text = "Drug Screen Group" Then
               If SaveFileDialog1.ShowDialog() = DialogResult.OK Then
                   'Get clickonce deployment version.
                   Dim exporter As New ExportToPDF(Me.RadGridView1)

                   'PDF formatting.
                   Me.RadGridView1.Columns("IntakeDate").ExcelExportType = DisplayFormatType.ShortDate
                   exporter.FileExtension = "pdf"
                   exporter.PageTitle = "Drug Screen Group"
                   exporter.FitToPageWidth = True
                   exporter.PdfExportSettings.Author = GeneralCode.FirstName & " " & GeneralCode.SurName
                   exporter.PdfExportSettings.Creator = My.Application.Info.Version.ToString
                   exporter.PdfExportSettings.Title = "Drug Screen Report"
                   exporter.ExportVisualSettings = True
                   AddHandler exporter.HTMLCellFormatting, AddressOf htmlExporter_HTMLCellFormatting
                   exporter.RunExport(Me.SaveFileDialog1.FileName)

                   'Load agency referrals here.
                   Dim myCommand As New MySqlCommand
                   Dim myAdapter As New MySqlDataAdapter
                   Dim myData As New DataTable
                   MySQL.mysqlOpen()
                   myCommand.Connection = MySQL.conn

                   'Update program log.
                   myCommand.CommandText = "INSERT INTO manalive.programlog (userID, eventID, eventDescription, eventDetail) VALUES ('" & GeneralCode.ID & "', 'M12', 'Drug Screen Group Export PDF', '" & GeneralCode.UserID & "')"
                   myCommand.ExecuteNonQuery()
                   MySQL.mysqlClose()

                   'Send desktop alert for save.
                   frmParent.DesktopAlert = "Datum"
                   frmParent.DesktopContent = RDLDataType.Text & " has been exported as PDF file."

               End If
           End If
       Catch ex As Exception
           MsgBox("Error exporting to Excel.", MsgBoxStyle.Information)
       End Try

[Jeffrey]

Forgot to include this in previous post as this is the sub I'm using along with code I just posted:

Private Sub htmlExporter_HTMLCellFormatting(sender As Object, e As HTMLCellFormattingEventArgs)
      Try
          'Format datetime column in PDF.
          If e.GridColumnIndex = 3 AndAlso Not [String].IsNullOrEmpty(e.InnerCellValue.ToString()) Then
              e.HTMLCellElement.Value = DirectCast(e.InnerCellValue, DateTime).ToString("MM/dd.yyyy")
          End If
      Catch ex As Exception
          MsgBox("Problem converting value in Intake Date column.", MsgBoxStyle.Information)
      End Try
  End Sub

[Jeffrey]

Sorry, long day this is the correct sub:

Private Sub radGridView1_SortChanged(sender As Object, e As GridViewCollectionChangedEventArgs)
       radGridView1.GridNavigator.SelectFirstRow()
   End Sub

[Dess | Tech Support Engineer, Principal]

Hello Jeffrey,

Thank you for writing.

I was unable to reproduce the performance issue you are facing with the latest version (Q1 2014 SP1). I have attached my sample project. Feel free to modify it on a way to reproduce the experienced issue and get back to me, providing the sample code so I can investigate the precise case. Thank you in advance.

P.S. It is possible to call EnsureVisible method for the first row in the sorted data, which may speed up the performance in some cases.

Private Sub RadGridView1_SortChanged(sender As Object, e As GridViewCollectionChangedEventArgs) _
Handles RadGridView1.SortChanged
    RadGridView1.ChildRows(0).EnsureVisible()
    RadGridView1.GridNavigator.SelectFirstRow()
End Sub

You can set the threshold, which defines what sorting algorithm will be used. When the items count is greater than the threshold, BinaryTree will be used to perform the sorting operations. You can use the following code:

Dim dataView As RadDataView(Of GridViewRowInfo) = TryCast(Me.RadGridView1.GridViewElement.Template.ListSource.CollectionView, RadDataView(Of GridViewRowInfo))
Dim indexerField As FieldInfo = GetType(RadDataView(Of GridViewRowInfo)).GetField("indexer", BindingFlags.NonPublic Or BindingFlags.Instance)
Dim indexer As HybridIndex(Of GridViewRowInfo) = TryCast(indexerField.GetValue(dataView), HybridIndex(Of GridViewRowInfo))
indexer.Threshold = 500

I am looking forward to your reply.

Regards,
Desislava
Telerik