Question

when i checked [checked box] data on my page (1) and then go on to next page (2) through paging(bottom button of pages like [1234]) and then checked data on page (2).

when i came back to page (1) then it remain unchecked as i don’t checked anything!!!

all the things remains at its original positions. all are unchecked on both pages .
when coming from 1 page to page 2 (check-boxes of page 1 forget his value and get unchecked) and after when coming from page 2 to page 1 same thing happens.
sorry for my bad and rough English.
any suggestion??

Answer 1

If its a gridview or any repeater control try this

Gridview HTML

<asp:GridView ID="GridView1" runat="server" 
AutoGenerateColumns="False" AllowPaging="True"  
PageSize="5" Width="324px" DataKeyNames="CategoryID" 
OnPageIndexChanging="GridView1_PageIndexChanging">
<Columns>
<asp:BoundField DataField="CategoryID" HeaderText="CategoryID" />
<asp:BoundField DataField="CategoryName" HeaderText="CategoryName" />
<asp:TemplateField HeaderText="Select">
<ItemTemplate>
<asp:CheckBox ID="CheckBox1" runat="server" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

CS Codes

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
  RememberOldValues();
  GridView1.PageIndex = e.NewPageIndex;
  BindData();
  RePopulateValues();
}

And

private void RememberOldValues()
{
  ArrayList categoryIDList = new ArrayList();
  int index = -1;
  foreach (GridViewRow row in GridView1.Rows)
  {
   index = (int) GridView1.DataKeys[row.RowIndex].Value;
   bool result = ((CheckBox)row.FindControl("CheckBox1")).Checked;

  // Check in the Session
  if (Session[CHECKED_ITEMS] != null)
   categoryIDList = (ArrayList)Session[CHECKED_ITEMS];
  if (result)
  {
  if (!categoryIDList.Contains(index))
   categoryIDList.Add(index);
  }
  else
   categoryIDList.Remove(index);
  }
  if (categoryIDList != null && categoryIDList.Count > 0)
   Session[CHECKED_ITEMS] = categoryIDList;
}

And

private void RePopulateValues()
{
  ArrayList categoryIDList = (ArrayList)Session[CHECKED_ITEMS];
  if (categoryIDList != null && categoryIDList.Count > 0)
  {
  foreach (GridViewRow row in GridView1.Rows)
  {
   int index = (int)GridView1.DataKeys[row.RowIndex].Value;
  if (categoryIDList.Contains(index))
  {
   CheckBox myCheckBox = (CheckBox) row.FindControl("CheckBox1");
   myCheckBox.Checked = true;
  }
  }
  }
}

Bind Data Code

EDIT

/* QUERY */
private const string QUERY_SELECT_ALL_CATEGORIES = "SELECT * FROM Categories";

private void BindData()
{
  SqlConnection myConnection = new SqlConnection(ConnectionString);
  SqlDataAdapter ad = new SqlDataAdapter(QUERY_SELECT_ALL_CATEGORIES,
  myConnection);
  DataSet ds = new DataSet();
  ad.Fill(ds, "Categories");
  GridView1.DataSource = ds;
  GridView1.DataBind();
}

For more details chk this Maintaining_State_of_CheckBoxes