Get Row Index on click of Radio Button in GridView

Try this:

protected void Button1_Click(object sender, EventArgs e)
{
    int Id = 0;
    foreach (GridViewRow row in GridView1.Rows)
    {
        RadioButton rb = (RadioButton)row.FindControl("RadioButton1");
        if (rb.Checked)
        {
            Id =Convert.ToInt32(GridView1.Rows[row.RowIndex].Cells[1].Text);
            //Add your code
        }
    }
}

Please refer: Using a Radio Button in a GridView[^]

Try this:
aspx code:

<asp:GridView ID="gvItems" runat="server" AutoGenerateColumns="false"
    OnRowCommand="gvItems_RowCommand">
    <Columns>
        <asp:ButtonField ButtonType="Image" ImageUrl="~/radioButtonOFF.gif" CommandName="ibtnRadio" />
        <asp:BoundField HeaderText="Item" DataField="Name" />
    </Columns>
</asp:GridView>

cs code:

protected void gvItems_RowCommand(object sender, GridViewCommandEventArgs e)
{

    if (e.CommandName == "ibtnRadio")
    {
        int rowIndex = int.Parse(e.CommandArgument.ToString());
        //your code here
    }
}

Have look on following link
http://technico.qnownow.com/2012/05/07/radiobutton-in-asp-net-gridview/[^]

in .cs file add this code on gridView_rowdataBound event
protected void Grv_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
RadioButton Rdn = (RadioButton)e.row.FindControl("RadioButton1");
TextBox Txt = (TextBox)e.row.FindControl("TextBox1");

Rdn.Row.Attributes.Add("onclick", "RdnClick(" + e.Row.RowIndex + "," + Txt.ClientID + ");");

}
}


in js write this script

function RdnClick(idx,Txt)
{
alert('Row index of gridview is :-' + idx)
Txt.disabled=false; // for enable text box of particular row
}