How to Allow User to Check Only One Row at a Time in Grid View

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.

SQL Server part

Add Some Records

Web Forms Part

<asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server">
<Columns>
<asp:TemplateField HeaderText ="StateName">
<ItemTemplate>
<asp:CheckBox ID="CheckBox1" Text='<%# Eval("StateName")%>' AutoPostBack="true" runat="server" onclick="CheckBoxCheck(this);" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

You need to add a connection string above the Page load.

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.

<connectionStrings>
<add name="Myconstr" connectionString="data source=SAI-PC; Database=AllSampleCode; user id=sa; password=Pass$123 ;" providerName="system.data.sqlclient"/>
</connectionStrings>

Binding Grid View on the Page Load event.

Now to create a method for binding records for the Grid View.

private void getrecords()
{
SqlCommand cmd = new SqlCommand("select StateID ,StateName from StateMaster ", con);
cmd.CommandType = CommandType.Text;
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataTable dt = new DataTable();
da.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();
}
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.

Using Server event ( Checked Changed Event )

<asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server">
<Columns>
<asp:TemplateField HeaderText="StateName">
<ItemTemplate>
<asp:CheckBox ID="CheckBox1" Text='<%# Eval("StateName")%>' AutoPostBack="true" runat="server" OnCheckedChanged="CheckBox1_CheckedChanged" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
{
CheckBox chk = (CheckBox)sender;
GridViewRow gv = (GridViewRow)chk.NamingContainer;
int rownumber = gv.RowIndex;
if (chk.Checked)
{
int i;
for (i = 0; i <= GridView1.Rows.Count - 1; i++)
{
if (i != rownumber)
{
CheckBox chkcheckbox = ((CheckBox)(GridView1.Rows[i].FindControl("CheckBox1")));
chkcheckbox.Checked = false;
}
}
}
}

Final output

Happy coding.