C# – oncheckedchanged not firing for CheckBox when in GridView

Well, this question was asked more than a month ago and may be irrelevant now, but @LFSR was kind enough to edit it recently, it's in the "Active questions" list.

Since it remains unanswered (224 views!), I thought I should give it a go:

The problem is that in the context of a GridView, the DropDownList(referred to hereafter as DDL) is a dynamic control and therefore its events need to be reattached upon Postback.

When this concept is understood, the solution becomes relatively simple :

ASPX:

<asp:DropDownList ID="DDL1" runat="server" AutoPostBack="true" OnSelectedIndexChanged="DDL1_SelectedIndexChanged">
  <asp:ListItem Text="Review" Value="Review" Selected="True">Review</asp:ListItem>
  <asp:ListItem Text="Level1" Value="lvl1">Send Back to Level1</asp:ListItem>
</asp:DropDownList>

CS Code:

protected void Page_Load(object sender, EventArgs e)
{
  if(!Page.IsPostBack)
  {
    // Bind the GridView to something.
    DataBindGrid();
  }
}

protected void DDL1_SelectedIndexChanged(object sender, EventArgs e)
{
  this.lblCity.Text = ((DropDownList)sender).SelectedValue;
}

protected void grdPoll_RowDataBound(object sender, GridViewRowEventArgs e)
{
  if(Page.IsPostBack)
  {
    if(e.Row.RowType == DataControlRowType.DataRow)
    {
      DropDownList ddl = e.Row.FindControl("DDL1") as DropDownList;
      if(ddl != null)
      {
        ddl.SelectedIndexChanged += new EventHandler(DDL1_SelectedIndexChanged);
      }
    }
  }
}

Could you replace the code in your chkJobID_CheckedChanged event handler with this:

Response.Write(DateTime.Now.ToLongTimeString());

Then view the page and try checking and unchecking the checkbox. This will tell us if the event handler is firing for both check and uncheck actions, which should help us narrow down the problem.

--Jeremy