Object reference not set to an instance of an object for label

Question

I am trying to set label text which resides in gridview on RowDataBound event of gridview.The code for the same is as follows:

protected void GridView2_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        int day = Convert.ToInt32(DropDownList3.SelectedValue);
        int days = System.DateTime.DaysInMonth(2013,day);
        Label lab = (Label)e.Row.FindControl("d");
        lab.Text = days.ToString();
    }
}

GRIDVIEW STRUCTURE:

<asp:GridView ID="GridView2" runat="server" OnRowDataBound="GridView2_RowDataBound" />
                <asp:BoundField DataField="name" HeaderText="Name" SortExpression="n" />
                <asp:BoundField DataField="dept" HeaderText="Department" SortExpression="d" />
                <asp:BoundField DataField="code" HeaderText="Employee Code" SortExpression="c" />
                <asp:TemplateField HeaderText="Total days" >
                <itemtemplate>
                    <asp:Label ID="d" runat="server" Text="" />
                </itemtemplate>
                </asp:TemplateField>
                </asp:GridView>

In the above code,'d' is the id of the label in the gridview.On the highlighted line i am getting error that OBJECT REFERENCE NOT SET TO INSTANCE OF AN OBJECT.As far as I understand, the new label is not being created.Then how to assign values calculated in this event to gridview's label?

Debug your code and check what you get with e.Row.FindControl("d") I guess that this is null. — Tomtom, Mar 06 '13 at 06:44
Almost all cases of `NullReferenceException` are the same. Please see "[What is a NullReferenceException in .NET?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-in-net)" for some hints. — John Saunders, Mar 06 '13 at 06:50
i know that it is null,but i dont know the way to solve it...can you please suggest me. — , Mar 06 '13 at 06:56
The documentation explains that the [`FindControl` method](http://msdn.microsoft.com/en-us/library/486wc64h.aspx) will return `null` if the specified control does not exist. — Jeppe Stig Nielsen, Mar 06 '13 at 06:58
Please update your post and do not put the code in a comment — Tomtom, Mar 06 '13 at 07:07
i just want that calculated value of 'days' should be displayed in gridview,thats it..for that i am trying to assign days to label and that label to 'd' that is label in gridview... — , Mar 06 '13 at 07:08
@tomtom...sorry...i am newbie,will take care now onwards.....please have a look at updated question. — , Mar 06 '13 at 07:09

tariq · Answer 1 · 2013-03-06T07:17:06.857

1

 <asp:GridView ID="GridView1" runat="server" OnRowDataBound="GridView2_RowDataBound">
        <Columns>
            <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="n" />
            <asp:BoundField DataField="ID" HeaderText="Department" />
            <asp:BoundField DataField="Seats" HeaderText="Employee Code" />
            <asp:TemplateField HeaderText="Total days">
                <ItemTemplate>
                    <asp:Label ID="d" runat="server" Text=""></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>

where is your columns tag, put in the columns tag and try

edited Mar 06 '13 at 07:17

answered Mar 06 '13 at 07:11

tariq

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still not working.Issue is as it is....can you suggest me any other way round to display days values in the gridview...? – Mar 06 '13 at 07:17
i marked it as answer,but not able to upvote as i am new to stackoverflow.It requires 15 reputation for that.thanks once again. – Mar 06 '13 at 07:31

Object reference not set to an instance of an object for label

1 Answers1