Always getting checkbox as false in grid

Question

i have checkboxes in a grid. I am trying to access them from codebehind and get the data for checked /unchecked rows.But even after the checkboxes being checked I am getting them as Checked property as false only:

Aspx:

  <table width="100%">
            <asp:GridView ID="grdRequestsPending" runat="server" Width="100%" AutoGenerateColumns="false"
                BorderWidth="1px" BorderStyle="Solid" Style="margin-left: 0px" BorderColor="#ffcc00"
                RowStyle-BorderColor="#ffcc00" RowStyle-BorderStyle="Solid" RowStyle-BorderWidth="1px"
                GridLines="Both" DataKeyNames="ReqID,ApproverComments" On="grdRequestsPending_ItemDataBound" OnRowDataBound="grdRequestsPending_RowDataBound"
                OnPreRender="grdRequestsPending_PreRender">
                <RowStyle CssClass="dbGrid_Table_row" />
                <HeaderStyle CssClass="dbGrid_Table_Header" />
                <Columns>
                    <asp:TemplateField>
                        <HeaderTemplate>
                            <asp:Label ID="lblSelect" Text="Select All" runat="server"></asp:Label><br />
                            <asp:CheckBox ID="SelectAll" onclick="javascript:checkAllBoxes(this);" TextAlign="Left"
                                runat="server" />
                        </HeaderTemplate>
                        <ItemStyle Width="2%" />
                        <ItemTemplate>
                            <asp:CheckBox ID="chkReq" runat="server"/>
                        </ItemTemplate>
                        <ItemStyle HorizontalAlign="Center" Width="7%" />
                    </asp:TemplateField>
       </Columns>

But when I am checking these I am always getting them as false in code behind:

        protected void UpdateVMRequestStatusByCapSupLead(int StatusId)
    {
        try
        {

            DataTable dt = new DataTable();
            dt.Columns.Add("ReqId", typeof(int));
            dt.Columns.Add("StatusId", typeof(int));
            dt.Columns.Add("ModifiedBy", typeof(string));
            dt.Columns.Add("ModifiedDate", typeof(string));
            dt.Columns.Add("txtCommentSupLead", typeof(string));
            foreach (GridViewRow gr in grdRequestsPending.Rows)

            {
                CheckBox chk = (CheckBox)gr.FindControl("chkReq");

                if (chk.Checked)
                {
                    strReqId = strReqId + grdRequestsPending.DataKeys[gr.RowIndex].Value.ToString() + ',';

                    TextBox txtCommentSupLead = (TextBox)gr.FindControl("txtCommentSupLead");
                    dt.Rows.Add(dt.NewRow());
                    dt.Rows[dt.Rows.Count - 1]["ReqId"] = Convert.ToInt32(grdRequestsPending.DataKeys[gr.RowIndex].Value);
                    dt.Rows[dt.Rows.Count - 1]["StatusId"] = StatusId;
                    dt.Rows[dt.Rows.Count - 1]["ModifiedBy"] = Session["UserAccentureID"].ToString();
                    dt.Rows[dt.Rows.Count - 1]["txtCommentSupLead"] = txtCommentSupLead.Text;
                    dt.Rows[dt.Rows.Count - 1].AcceptChanges();
                    dt.Rows[dt.Rows.Count - 1].SetModified();
                }
            }

I am not getting the problem.I am gettign the control also correctly..

Answer 1

Here is a simple example of populating a checkbox in a gridview and getting the values out on a button click

Default.aspx

<asp:GridView ID="gv" 
              runat="server" 
              AutoGenerateColumns="false" 
              OnRowDataBound="gv_RowDataBound">
  <Columns>
    <asp:TemplateField>
      <ItemTemplate>
        <asp:CheckBox ID="chkReq" runat="server" />
      </ItemTemplate>
    </asp:TemplateField>
  </Columns>
</asp:GridView>
<br />
<asp:Button ID="btnSubmit" 
            runat="server" 
            OnClick="btnSubmit_Click" 
            Text="Submit" />

Default.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{
  if (!IsPostBack)
  {
    //Create 20 rows
    gv.DataSource = Enumerable.Range(1, 20);
    gv.DataBind();
  }
}

protected void btnSubmit_Click(object sender, EventArgs e)
{
  var isCheckedList = new List<bool>();

  for(var index = 0; index < gv.Rows.Count; ++index)
  {
    var chkReq = (CheckBox)gv.Rows[index].FindControl("chkReq");
    isCheckedList.Add(chkReq.Checked);
  }

  //Look at isCheckedList to get a list of current values.
  System.Diagnostics.Debugger.Break();
}

protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
  if (e.Row.RowType == DataControlRowType.DataRow)
  {
    var index = e.Row.RowIndex;

    //Strongly Bind Controls
    var chkReq = (CheckBox)e.Row.FindControl("chkReq");
    chkReq.Text = "Item " + index.ToString();
  }
}

Since you did not show all of your code, it could be an issue like Tim Schmelter said or it could be something else. This example provides you with the basics that are needed to retrieve a checkbox value from a grid view.

Answer 2

I assume that you're always databinding your GridView and not only if(!Page.IsPostBack)....

So put this in page_load

protected void Page_Load(object sender, EventArgs e)
{                        
    if(!Page.IsPostBack)
    {
        DataBindControls(); // like GridView etc.
    }
}

If you DataBind controls they will lose their changes and ViewState. Even events aren't triggered then. So you should do that only on the first load if EnableViewState="true".