DataGridのテンプレート列にラジオボタンを配置

  Protected Sub btnGetCategoryiD_Click( _
    ByVal sender As Object, ByVal e As System.EventArgs)
    If Me.GridViewSelectedIndex > 0 Then
      Dim strCategoryID As String = GridView1.DataKeys(Me.GridViewSelectedIndex).Value.ToString
      lblMessage.Text = String.Format("Selected ID: {0}", strCategoryID)
    End If
  End Sub
  
  Protected Sub GridView1_RowCreated( _
     ByVal sender As Object, _
     ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs)
    If e.Row.RowType = DataControlRowType.DataRow Then
      Dim output As Literal = CType(e.Row.FindControl("RadioButtonMarkup"), Literal)
      output.Text = String.Format("<input type=""radio""
                     name=""RadioButtonGroup""
                     id=""RowSelector{0}"" value=""{0}""", e.Row.RowIndex)

      If Me.GridViewSelectedIndex = e.Row.RowIndex Then
        output.Text &= " checked=""checked"""
      End If
      output.Text &= " />"
    End If
  End Sub
  
  Private ReadOnly Property GridViewSelectedIndex() As Integer
    Get
      If String.IsNullOrEmpty(Request.Form("RadioButtonGroup")) Then
        Return -1
      Else
        Return Convert.ToInt32(Request.Form("RadioButtonGroup"))
      End If
    End Get
  End Property