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Help-How to sort columns in a table web control that's generated dynamically in code behind page?

Hi,

I am using table web control in code behind to generate a result table. When a button clicked, it'll display the result. Now I need to place sorting on each column. I tried to declare a link button event and added event handler for the click event. But it didn't work.

Can anybody tell me how to add a sort function?

Thank you.

Ping

***** =============================================================********
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration

Public Class test
Inherits System.Web.UI.Page

#Region " Web Form Designer Generated Code "

'This call is required by the Web Form Designer.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

End Sub

Protected WithEvents btnDisplay As System.Web.UI.WebControls.Button
Protected WithEvents tblResult As System.Web.UI.WebControls.Table
protected withEvents b as system.web.ui.webcontrols.linkbutton
***** =============================================================********
'NOTE: The following placeholder declaration is required by the Web Form Designer.
'Do not delete or move it.
Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
'CODEGEN: This method call is required by the Web Form Designer
'Do not modify it using the code editor.
InitializeComponent()
End Sub

#End Region

Protected sortorder As String = ""

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

'to add event handler on page load
addhandler b.click, addressof sorttotal_click

If Not Page.IsPostBack Then
showChoices()
Else
End If
End Sub 'Page_Load

Private Sub btnDisplay_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDisplay.Click
'display the result table
displayResults()
End Sub

Private Sub displayResults()

Dim conn As New SqlConnection(connectionString)
Dim daDetail As New SqlDataAdapter("tuition", conn)

Dim dtDetail As New DataTable
daDetail.Fill(dtDetail)

Dim dvDetail As New DataView(dtDetail)
dvDetail.Sort = sortorder

'Set a table width.
tblResult.Width = Unit.Percentage(90.0)

'****Create a new row for adding a table heading.
Dim tableHeading3 As New TableRow

If InStr(LCase(degreeSelected), "undergraduate") > 0 Then

'Create and add the cells that contain the ugr tuition column heading text.
Dim ugrTuitionHeading As New TableHeaderCell
ugrTuitionHeading.Text = "Tuition"
ugrTuitionHeading.HorizontalAlign = HorizontalAlign.Center
ugrTuitionHeading.CssClass = "tablehead2"
tableHeading3.Cells.Add(ugrTuitionHeading)
End If
If InStr(LCase(degreeSelected), "others") > 0 Then

'Create and add the cells that contain the others tuition column heading text.
Dim otherTuitionHeading As New TableHeaderCell
otherTuitionHeading.Text = "Tuition"
otherTuitionHeading.HorizontalAlign = HorizontalAlign.Center
otherTuitionHeading.CssClass = "tablehead2"
tableHeading3.Cells.Add(otherTuitionHeading)
End If

'Create and add the cells that contain total heading text.
Dim totalHeading2 As New TableHeaderCell
' totalHeading2.Text = "Total"
totalHeading2.HorizontalAlign = HorizontalAlign.Center
totalHeading2.CssClass = "tablehead2"

'create link button web server control and add to cell for sorting
***** =============================================================********
b.Text = "Total"
b.CssClass = "classname"
totalHeading2.Controls.Add(b)
***** =============================================================********
tableHeading3.Cells.Add(totalHeading2)

tblResult.Rows.Add(tableHeading3)

''****end of the heading text****''

End Sub

Protected Sub sortTotal_onclick(ByVal sender As Object, ByVal e As EventArgs) Handles b.Click
lblShow.Text = lblShow.Text & "<br>sorttotal_onclick"
sortorder = "total"
displayResults()
End Sub
End Class

iboutchkine

Shows how to sort a DataGrid's DataSet to provide sort functionality by clicking on the column headers.

Create a new WebForm and add a DataGrid to it called DataGrid1.
Right Click on the DataGrid and select the Property Builder, on the General section ensure that the
Allow Sorting Option is Checked.
Then Add this code to your VB Class:

Imports System.Data.SqlClient
Imports System.Data

Public Class WebForm1
Inherits System.Web.UI.Page

Protected WithEvents Label1 As _
System.Web.UI.WebControls.Label
Protected WithEvents DataGrid1 As _
System.Web.UI.WebControls.DataGrid

Private mstrSortCol As String

Private Sub Page_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load

'If this request is not a postback request
'the bind to our DataSource
If Not IsPostBack Then
BindData()
End If
End Sub

Private Sub BindData()

Dim c As SqlClient.SqlConnection
Dim da As SqlClient.SqlDataAdapter
Dim ds As DataSet
Dim strSQL As String
Dim strCon As String

'Set the SQL Query
strSQL = "SELECT CompanyName, ContactName, " & _
" ContactTitle, Phone, Fax FROM Customers "

'If there is a Sort Column Specified then
'Use it to sort the query
If mstrSortCol <> "" Then
strSQL += " ORDER BY " & mstrSortCol
End If

'Make Connection String.
strCon = "server=localhost;database=Northwind;uid=sa;pwd=;"

'Create and Open Connection
c = New SqlClient.SqlConnection(strCon)
c.Open()

'Perform Query and get the Results
da = New SqlDataAdapter(strSQL, c)

'Create a dataset
ds = New DataSet()

'Fill the Dataset
da.Fill(ds)

'Bind the Grid to the Dataset
DataGrid1.DataSource = ds
DataGrid1.DataBind()
End Sub

Private Sub DataGrid1_SortCommand(ByVal source As Object, _
ByVal e As System.Web.UI.WebControls.DataGridSortCommandEventArgs) _
Handles DataGrid1.SortCommand

'Grab the Name of the item to sort by
mstrSortCol = e.SortExpression()

'reset the data
BindData()
End Sub
End Class

wk_lp

ASKER

sorry. your reply is total irrelavant to my question. I didn't ask how to sort a datagrid or a datalist. I know how to do those. I am asking how to sort a table web control that's generated manually in code behind page. I don't use any of the datagrid, datalist and repeater in this page.

Thanks for the effort.

wk_lp

ASKER

The way I tried was to query the database, put it in a dataview, pass a sort order to the dataview. Then I loop through the dataview to create the table. For the table's header column, I created and added link button control so that when it's clicked, it'll post back to the same page. When it's clicked, it should run sortTotal_onclick sub. Instead, an error occurred saying that object reference is not set to an instance of the object and the line number pointed to addhandler line.

iboutchkine

Sorry I misunderstood your question

wk_lp

ASKER

I have figured this out myself. Thanks for your attention.

wk_lp

ASKER

I put the createButton function inside Page_init sub and that will recreate the control every time.

ASKER CERTIFIED SOLUTION

ee_ai_construct

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