Introduction

In this article we will learn how to select only one row of a GridView using RadioButtons whereas normally a RadioButton does not support selection of only one RadioButton within a row.

Background

In ASP.Net the GridView control does not support selection of a single RadioButton that works as a group across rows. Generally as you know a RadioButton is a control that works in a group for selecting only one option. If we take RadioButtonList control it will work everywhere, which applies to a GridView also but if we use only one RadioButton control for each row in GridView it will not allow us to select only one. Try selecting a RadioButton in every row; it will allow selection of multiple rows in GridView. Here we will see how to restrict the user to select only one RadioButton within a GridView control.

For doing this task I've written some Javascript function. This function actually I got from somewhere while Google search. We will step by step follow.

Step 1

Start new website. Put the GridView control on the Default.aspx page with RadioButton control in TemplateField like bellow.
  1. <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
  2. DataKeyNames="AuthId">
  3. <Columns>
  4. <asp:TemplateField ShowHeader="false">
  5. <ItemTemplate>
  6. <asp:RadioButton ID="rdbauthid" runat="server" onclick="javascript:CheckOtherIsCheckedByGVID(this);" />
  7. </ItemTemplate>
  8. </asp:TemplateField>
  9. <asp:BoundField HeaderText="AUTHOR NAME" DataField="AuthName" />
  10. <asp:BoundField HeaderText="AUTHOR LOCATION" DataField="AuthLocation" />
  11. </Columns>
  12. </asp:GridView>
In the above you may see that in the Click event of the RadioButton control I call a Javascript function.

Step 2

Write the script as below for checking the current selection of the RadioButton control; if more than one is selected then the other selection is removed. Other than this there are two more methods to do same task.
  1. <script type="text/javascript">
  2. function CheckOtherIsCheckedByGVID(spanChk) {
  3. var IsChecked = spanChk.checked;
  4. if (IsChecked) {
    spanChk.parentElement.parentElement.style.backgroundColor =     '#228b22';
  5. spanChk.parentElement.parentElement.style.color = 'white';
  6. }
  7. var CurrentRdbID = spanChk.id;
  8. var Chk = spanChk;
  9. Parent = document.getElementById("<%=GridView1.ClientID%>");
  10. var items = Parent.getElementsByTagName('input');
  11. for (i = 0; i < items.length; i++) {
  12. if (items[i].id != CurrentRdbID && items[i].type == "radio") {
  13. if (items[i].checked) {
  14. items[i].checked = false;
    items[i].parentElement.parentElement.style.backgroundColor =     'white'
  15. items[i].parentElement.parentElement.style.color = 'black';
  16. }
  17. }
  18. }
  19. }
  20. </script>
Step 3

Bind your GridView in aspx.cs page and run the application.

Conclusion

In this way we can restrict the user to select only one option via RadioButton in GridView.