Introduction

Most developers use a Grid View to display records.
Allowing the user to select only one row from this Grid View.
Here is an example I will show you.

Create Table State Master

SQL Server part
  1. CREATE TABLE [dbo].[StateMaster](
  2. [StateID] [int] IDENTITY(1,1) primary key NOT NULL,
  3. [StateName] [varchar](30) NULL,
  4. [StateCode] [varchar](50) NULL,
  5. [RecordStatus] [char](1) NULL,
  6. )
Add Some Records
Web Forms Part
  1. <asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server">
  2. <Columns>
  3. <asp:TemplateField HeaderText ="StateName">
  4. <ItemTemplate>
  5. <asp:CheckBox ID="CheckBox1" Text='<%# Eval("StateName")%>' AutoPostBack="true" runat="server" onclick="CheckBoxCheck(this);" />
  6. </ItemTemplate>
  7. </asp:TemplateField>
  8. </Columns>
  9. </asp:GridView>
You need to add a connection string above the Page load.
  1. SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Myconstr"].ToString());
And add a connection string in Web.config.
For making a connection with the database you need to add a connection string to the database; here is an example of that.
Just replace here with your database value.
  1. <connectionStrings>
  2. <add name="Myconstr" connectionString="data source=SAI-PC; Database=AllSampleCode; user id=sa; password=Pass$123 ;" providerName="system.data.sqlclient"/>
  3. </connectionStrings>
Binding Grid View on the Page Load event.
  1. protected void Page_Load(object sender, EventArgs e)
  2. {
  4. if (!IsPostBack)
  5. {
  6. getrecords();
  7. }
  9. }
Now to create a method for binding records for the Grid View.
  1. private void getrecords()
  2. {
  4. SqlCommand cmd = new SqlCommand("select StateID ,StateName from StateMaster ", con);
  5. cmd.CommandType = CommandType.Text;
  6. SqlDataAdapter da = new SqlDataAdapter();
  7. da.SelectCommand = cmd;
  8. DataTable dt = new DataTable();
  9. da.Fill(dt);
  10. GridView1.DataSource = dt;
  11. GridView1.DataBind();
  13. }
  15. Using JavaScript (Onclick)
In the head part of the .aspx page add the following JavaScript.
To see the details, use the Firefox add-on Firebug to debug it.
  1. <script type="text/javascript">
  2. function CheckBoxCheck(rb) {
  3. debugger;
  4. var gv = document.getElementById("<%=GridView1.ClientID%>");
  5. var chk = gv.getElementsByTagName("input");
  6. var row = rb.parentNode.parentNode;
  7. for (var i = 0; i < chk.length; i++) {
  8. if (chk[i].type == "checkbox") {
  9. if (chk[i].checked && chk[i] != rb) {
  10. chk[i].checked = false;
  11. break;
  12. }
  13. }
  14. }
  15. }
  16. </script>
Using Server event ( Checked Changed Event )
  1. <asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server">
  2. <Columns>
  3. <asp:TemplateField HeaderText="StateName">
  4. <ItemTemplate>
  6. <asp:CheckBox ID="CheckBox1" Text='<%# Eval("StateName")%>' AutoPostBack="true" runat="server" OnCheckedChanged="CheckBox1_CheckedChanged" />
  7. </ItemTemplate>
  8. </asp:TemplateField>
  9. </Columns>
  10. </asp:GridView>
  12. protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
  13. {
  15. CheckBox chk = (CheckBox)sender;
  16. GridViewRow gv = (GridViewRow)chk.NamingContainer;
  17. int rownumber = gv.RowIndex;
  19. if (chk.Checked)
  20. {
  21. int i;
  22. for (i = 0; i <= GridView1.Rows.Count - 1; i++)
  23. {
  24. if (i != rownumber)
  25. {
  26. CheckBox chkcheckbox = ((CheckBox)(GridView1.Rows[i].FindControl("CheckBox1")));
  27. chkcheckbox.Checked = false;
  28. }
  29. }
  30. }
  33. }
Final output
Happy coding.