'RadioButtonList1' has a SelectedValue which is invalid because it does not exist in the list of items.

Question

User-2026951251 posted

I know i'm getting this error because my database field is empty. How do I make the default selection to one of the items listed in the radiobuttonlist(which is inside a formview) when there is null value in the database or there is a value that doesn't match the items in the radiobuttonlist's listitems? Please help!

Answer 1

User-2026951251 posted

Actually I found out the solution. It was given in a blog.  

 Add an empty item to the list and then do some code in the OnDataBound event.  The code below works perfectly.

Thanks to whoever the blog owns to 

<asp:RadioButtonList ID="MyRadioButtonList" runat="server"
   SelectedValue='<%# Bind("Blah") %>'
   OnDataBound="MyRadioButtonList_DataBound">
      <asp:ListItem Value=""></asp:ListItem>
      <asp:ListItem Value="A"></asp:ListItem>
      <asp:ListItem Value="B"></asp:ListItem>
      <asp:ListItem Value="C"></asp:ListItem>
</asp:RadioButtonList>

protected void MyRadioButtonList_DataBound(object sender, EventArgs e)
{
      RadioButtonList list = (RadioButtonList)sender;
      ListItem blank = list.Items.FindByValue("");
      if (blank != null)
         list.Items.Remove(blank);
}

 

Answer 2

User1564875471 posted

in formView rowDatabound event handler ,you need something like this :

[ don't forget to replace "foreignKeyField" with the DataBase column name that the selected value is binded to  ]

    Protected Sub FormView1_DataBound(ByVal sender As Object, ByVal e As System.EventArgs) Handles FormView1.DataBound
        Dim ForeginKeyField As Object = DataBinder.Eval(FormView1.DataItem, "foreignKeyField")
        Dim Radiolist As RadioButtonList = FormView1.FindControl("RadiobuttonList1")

        If ForeginKeyField Is DBNull.Value OrElse String.IsNullOrEmpty(ForeginKeyField) OrElse Radiolist.Items.FindByValue(ForeginKeyField) Is Nothing Then

            ' set the selection to some defual value or index ,.. i  will choose to select the first item 
            Radiolist.SelectedIndex = 0

        Else
            ' the value is exists and correct
            Radiolist.SelectedValue = ForeginKeyField
        End If
    End Sub