ASP.NetControls

ASP.Net - RadioButtonList

RadioButtonList

The radiobuttonlist control is used to setup a group of radio controls - which you only want one to be selected.

Here is a sample

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<asp:RadioButtonList ID="rlBuildingUse" runat="server">
      <asp:ListItem Value="R">Residential</asp:ListItem>
      <asp:ListItem Value="M">Multi-Family</asp:ListItem>
      <asp:ListItem Value="C">Commercial</asp:ListItem>
</asp:RadioButtonList>

Here is how to programatically set which one is selected

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rlBuildingUse.SelectedIndex = rlBuildingUse.Items.IndexOf( _
    rlBuildingUse.Items.FindByValue("C"))

Here is how to bind a radio button list control to an object datasource

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<asp:RadioButtonList 
      ID="RadioButtonList1" 
      runat="server" 
      RepeatDirection="Horizontal"
      selectedvalue='<%# bind("LRC") %>'>
      <asp:ListItem>L</asp:ListItem>
      <asp:ListItem>R</asp:ListItem>
      <asp:ListItem>C</asp:ListItem>
</asp:RadioButtonList>

This works if the table will always have a value. but if this is an optional value, then you’ll need to be a bit more creative.

Formview

where the value in a radio button list is optional:

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<asp:RadioButtonList 
      ID="RadioButtonList1" 
      runat="server" 
      RepeatDirection="Horizontal">
      <asp:ListItem>L</asp:ListItem>
      <asp:ListItem>R</asp:ListItem>
      <asp:ListItem>C</asp:ListItem>
</asp:RadioButtonList>

Add some logic to the prerender event of the formview control.

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Protected Sub fv_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles fv.PreRender
    If fv.CurrentMode = FormViewMode.Edit Then
        '
        ' drop down controls are not bound to the form, so we must
        ' do this manually. 
        '
        Dim obj As bo_acad_LateralLine _
            = CType(fv.DataItem, bo_acad_LateralLine)

        If IsNothing(obj) Then
            ' skip - because there is not object
        Else

            ' left right center
            If Not IsNothing(CType(fv.FindControl("rblLRC"), RadioButtonList _
                    ).Items.FindByValue(obj.LRC)) Then

                CType(fv.FindControl("rblLRC"), DropDownList).SelectedValue _
                        = obj.LRC
            End If
        End If
    End If
End Sub

And some logic to the ItemUpdating event

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Protected Sub fv_ItemUpdating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.FormViewUpdateEventArgs) Handles fv.ItemUpdating
     '
     '       data column name                   control name
     e.NewValues("LRC") = CType(fv.FindControl("rblLRC"), RadioButtonList).SelectedValue
 End Sub

ASP.net 1.1 note

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Dim str As String _
  = vbCrLf & "<script> " & vbCrLf _
      & " function LookupID() " & vbCrLf _
      & " { var assetType;" & vbCrLf _
      & " if (document.forms[0].all('" & AssetTypeSelectorRadioButtonList.ClientID & "_0').checked) " & vbCrLf _
      & " assetType='Manhole'; " & vbCrLf _
      & " if (document.forms[0].all('" & AssetTypeSelectorRadioButtonList.ClientID & "_1').checked) " & vbCrLf _
      & " assetType='ServiceLine'; " & vbCrLf _
      & " if (document.forms[0].all('" & AssetTypeSelectorRadioButtonList.ClientID & "_2').checked) " & vbCrLf _
      & " assetType='SewerLine'; " & vbCrLf _
      & " var href='Lookup_All_modal.aspx' " & vbCrLf _
      & " + '?AssetCode=' + document.forms[0].all('" & AssetIDTextBox.ClientID & "').value " & vbCrLf _
      & " + '&AssetType;=' + assetType" & vbCrLf _
      & " ; " & vbCrLf _
      & " var args=''; " & vbCrLf _
      & " var X = window.showModalDialog(href, args, 'dialogHeight: 550px; dialogWidth:650px; resizable:yes; scroll:yes; status:yes; '); " & vbCrLf _
      & " if (X ) " & vbCrLf _
      & " { args = X.split('|'); " & vbCrLf _
      & " document.forms[0].all('" & AssetIDTextBox.ClientID & "').value=args[0]; " & vbCrLf _
      & " } " _
      & " } " _
      & " </script> "

' you want to do this
' if (document.forms[0].all('" & AssetTypeSelectorRadioButtonList.ClientID & "').options[1].selected) " & vbCrLf
' but what's rendered is individual radio controls.
' so then you want to do this
' if (document.forms[0].all('" & AssetTypeSelectorRadioButtonList.items(1).ClientID & "').selected) " & vbCrLf
' but an item doesn't have a client id
Page.RegisterStartupScript("LookupID", str)