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19 Comments »

• Christie — September 11, 2006 at 8:19 pm

  I figured checkboxes would be the same as textboxes.

  Here is what I am using:
  Checkbox chk = new CheckBox();
  //rdrAllA is an oledbdatareader, and I want to place the Id value from the table into the checkbox ID, strAName is a common name for every checkbox that is rendered (ex. strAName = “fun”)

  chk.ID = strAName + rdrAllA["Id"]; chk.Text = strAName + rdrAllA["Id"]; phFun.Controls.Add(chk); phFun.Controls.Add(new LiteralControl(”"));

  When I open the page, I do not see any checkboxes at all. When I step through the code it acts as if these checkboxes are being rendered. Any Ideas?

• Adam — September 12, 2006 at 9:51 am

  I would say that it is either the placement of the PlaceHolder control in your HTML or something in the way you add the checkboxes to it.

  One thing to note is that you must add the controls to the PlaceHolder before the definition of the tag (ie the <asp:PlaceHolder /> code). If you add them after they will not render.

  Another thing to note (although not your issue) is that if you don’t generate a new CheckBox object for each entry you will only end up with one rendered at the end since really you have only put one object in the PlaceHolder.

  If that doesn’t solve your problem send me your code, I can take a look at it for you. ahewgill@gmail.com

• Rizwan(Bangladesh) — October 18, 2006 at 3:17 pm

  Good and Helpfull

• ken miller — December 19, 2006 at 8:25 am

  I find the use of dynamic, bound checkboxlist control to be straightforward, very useful, but with the usual layout problems of dynamically generated controls.

  This example creates a range of checkboxlists by category, binds each to a datasource, and sets the checked property of each.

  First get the Checkboxlist topics

  Dim candidate_id As Integer = 1
  Dim dsSkillgroups As DataSet
  Dim dsSkills
  Dim row As DataRow
  Dim cblSkill As CheckBoxList
  
  ' Populate dataset
  dsSkillgroups = GetSkillGroup()
  
  For Each row In dsSkillgroups.Tables(0).Rows
    cblSkill.ID = row("skillgroup_id")
    cblSkill.RepeatDirection = RepeatDirection.Horizontal
  
    ' Now bind the CheckBoxList to a dataset
    Dim dsSkills As New DataSet
    dsSkills = db.GetDataSet(ssql, "skills")
  
    cblSkill.DataSource = dsSkills
    cblSkill.DataTextField = "text"
    cblSkill.DataValueField = "id"
    cblSkill.DataBind()
  
    ' Now set the selected property of each checkbox
    ' to the value of "IsChecked" returned in the dataset
    x = 0
    For Each row In dsSkills.Tables(0).Rows
      If row("Checked") = 1 Then
        cbox.Items(x).Selected = True
      End If
      x = x + 1
    Next
    ' Add the CheckBoxList
    Me.phSkills.Controls.Add(cblSkill)
  Next
  

  This works (The example code above is edited as an explanation). However, I’ve got very little control over layout. I’d like to start each CheckBoxList on its own line, preceeded by a label. However each control appears to be enclosed in an inherent tag.

• Mukesh — December 19, 2006 at 9:43 am

  Hi,

  I added the dynamic controls and when i am clicking a dynamic button, the postback is fired and the dynamic controls are cleared. pls give an idea how to retreive the dynamic controls and data entered in them.

  Thanks in advance

• Adam — December 19, 2006 at 10:10 am

  The second last code example shows how to collect the values back from the checkboxes after postback. You need to have a list of the IDs you used (using the same method you generated them with initially) and then just lookup the value in Request.Form. Also dynamic controls do not reappear on their own, you must redraw them on postback or your page will only have the static controls on it.

• Gene — January 5, 2007 at 11:59 am

  I came accross this situation with a dynamically generated web form for a project that I created. The solution to the problem of being able to iterate through the controls when posting back was to create the form in the LoadViewstate Override
  Protected Overrides Sub LoadViewState(ByVal savedState As Object)
  LoadEscalationTable()
  End Sub

  where sub loadEscalationTable creates dynamic asp:rows and asp:columns containing dynamic dropdownlist controls with names and Id’s of email recipients. This worked out to be a foolproof solution for persisting dynamic data on a page for postback. Hope this helps.

  -Gene

• Tousal — May 18, 2007 at 4:26 pm

  Great solution!

  One comment though. I create the checkboxes in the Page_Load method of the form. On postbacks, the state of the checkboxes persists. I was expecting the checked property for all the checkboxes to be cleared since they’re being recreated on every postback but this doesn’t happen. The ones that were checked before the postback remain checked.

• Sohail Raza — August 14, 2007 at 1:28 am

  I am trying to add LinkButtons in a web page which is inside a Master Page but I cannot catch the click event.
  Then I tried the same on a separate web page and it works.

  Why it is not working in the first case when my web page is inside a Master Page.

  Please help me.

• Samuel — October 4, 2007 at 4:40 am

  I tried the checkbox on my code page but it wasnt working. I was gettting the id as u did but couldnt get the checked properties. so i used urs and the same thing is still happening.

• chandu — November 20, 2007 at 6:25 am

  hi

  i utilize these controls in prj these dyamically
  controls are useful while pls send the code
  of combobox,gridview control code dynamically

  chandu(:-

• rahil — February 12, 2008 at 3:35 am

  i want define dynamic chechkbox and when i click on it(CheckedChanged) the visible of my button become true.
  please help me
  thaks

• Sathya — February 26, 2008 at 1:12 am

  Hi

  I tried to fire the Button click event on Dynamic button control. But it’s won’t fire.

  Please anyone help me

  thanks

• arvind — February 28, 2008 at 7:55 am

  how can i fire event on dynamically generated button.
  problem is that:
  i generate dynamically 3 dropdown list and one button on click of static button.
  when i click on dynamic generate button then all dynamic generate controlls hide then how can i catch selected value of dropdown list..
  for further process………

• Praveen Kunwar — May 28, 2008 at 4:52 am

  Hi Gene.

  Thanks alot for your help.
  Actually i was created dynamic checkbox control in gridview. The procedure i am decribing….
  Firstly i bounded the gridview with datasource. Then with Row DataBound eg (protected void gvData_DataBound(object sender, GridViewRowEventArgs e)), i created the dynamic checkbox control.
  Then i used viewstate eg -
  protected override void LoadViewState(object savedState)
  {
  BindGrid();
  base.LoadViewState(savedState);
  }

  Its successfully work.

  Hope it help.

• Praveen Kunwar — May 28, 2008 at 4:57 am

  Hi Arvind,

  For dynamic generated button, you can add event on row databound event.
  Eg.
  protected void gvData_DataBound(object sender, GridViewRowEventArgs e)
  {
  foreach (GridViewRow Row in GrdViewSearch.Rows)
  {
  for (int i = 0; i < Row.Cells.Count; i++)
  {
  if (Row.Cells[i].Text == “1″)
  {
  CheckBox chkCheckBox = new CheckBox();
  TableCell tcCheckCell = new TableCell();
  tcCheckCell.ID = “tcCell” + i;
  chkCheckBox.ID = “_#_CHK_#_” + i;
  chkCheckBox.Checked = true;
  chkCheckBox.Attributes.Add(”onClick”, “SelectOneDynamic(this.id, this.checked);”);
  tcCheckCell.Controls.Add(chkCheckBox);
  Row.Cells.RemoveAt(i);
  Row.Cells.AddAt(i, tcCheckCell);
  }

  Actually in my dataset, the checkbox value has 1 or 0.
  So i am replacing that particular “CELL” with checkbox cheked.

  Hope it will help

• Lonso — July 20, 2008 at 11:58 am

  Hi,
  I have a question concerning dynamically created linkbuttons.

  I have a webpage where I create in the page_load event about 10.000 linkbuttons dynamically. Each of them gets a unique ID of course and all of the share the same click event handler (but with different command arguments).

  When one of these linkbuttons is clicked, a pageback occurs. I understand, that I have to recreate the dynamically created linkbuttons (and I’ve seen that this works) - but creation of 10.000 buttons takes quite a while. I would prefer to only recreate the one which was actually pressed and then call the click method defined in the event handler (with the arguments assigned to the button).

  Is this possible? It might be sufficient to get the ID of the clicked button. How do I retrieve this ID?

• Omer — August 25, 2008 at 10:08 pm

  This is what I was looking for for hours all over the internet. By far the best solution out there.

  Thank you!

• Dynamically add user control under UpdatePanel in ASP.NET « 麥克斯做個不宅的工程師 — October 2, 2008 at 1:06 am

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