Add radio button list items programmatically in asp.net

Question

I have a radio button list whose items I need to add on Page_Load

aspx code

<asp:radioButtonList ID="radio1" runat="server" RepeatLayout="Flow" RepeatDirection="Horizontal">
</asp:radioButtonList>

code behind

protected void Page_Load(object sender, EventArgs e)
{
    RadioButtonList radioList = (RadioButtonList)Page.FindControl("radio1");
    radioList.Items.Add(new ListItem("Apple", "1"));
}

After the control reaches radioList.Items.Add

I keep getting the Object reference not set to instance of an object error

What am I doing wrong?

Answer 1

You don't need to to do a FindCOntrol. As you used the runat="server" attributes, just get the reference of your RadioList via its name "radio1"

protected void Page_Load(object sender, EventArgs e)
{
    radio1.Items.Add(new ListItem("Apple", "1"));
}