为什么rowdatabound在gridview中找不到链接按钮？

Question

I am trying to get link button from gridview via RowDataBound but it returns null, Why ? The name is correct. Even you can see in the code but still it doesn't work.

GridView:

     <asp:GridView ID="grdViewWorks" OnRowDataBound="grdViewWorks_RowDataBound" runat="server" OnRowCommand="grdViewWorks_RowCommand" AutoGenerateColumns="false" EmptyDataText="No Data Found"
CssClass="table table-responsive table-bordered table-striped">
    <Columns>
        <asp:TemplateField HeaderText="Work No">
            <ItemTemplate>
                <asp:Label ID="lblWorkNo" runat="server" Text='<%# Eval("WorkNo") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="NIT No">
            <ItemTemplate>
                <asp:Label ID="lblNITNo" runat="server" Text='<%# Eval("NIT_No") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="WorkName" HeaderText="Work Name" />
        <asp:BoundField DataField="OpeningDate" HeaderText="Opening Date" />
        <asp:BoundField DataField="OpeningTime" HeaderText="Opening Time" />
        <asp:BoundField DataField="OrganizationName" HeaderText="Organization" />
        <asp:BoundField DataField="OfficeName" HeaderText="Office" />
        <asp:TemplateField HeaderText="Show Contractors">
            <ItemTemplate>
                <asp:LinkButton ID="btnShowContractors" runat="server" Text="Show Contractors"
                    OnClick="btnShowContractors_Click"></asp:LinkButton>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

.cs

protected void grdViewWorks_RowDataBound(object sender, GridViewRowEventArgs e)
{
    try
    {
        LinkButton lb = e.Row.FindControl("btnShowContractors") as LinkButton;
        ScriptManager.GetCurrent(this).RegisterPostBackControl(lb);
    }
    catch (Exception ex)
    {

        Utility.Msg_Error(this.Master, ex.Message);
    }
}

lb is always null. Why ?

Answer 1

before putting anything on the rowdatabound event you have to use this condition

  if (e.Row.RowType == DataControlRowType.DataRow)
    {
       LinkButton lb = e.Row.FindControl("btnShowContractors") as LinkButton;
        ScriptManager.GetCurrent(this).RegisterPostBackControl(lb);
     }

Answer 2

Try this way

if (e.Row.RowType == DataControlRowType.DataRow)
{
LinkButton lb = e.Row.FindControl("btnShowContractors") as LinkButton;
}