Selecting All CheckBoxes in GridView

<script type=”text/javascript”> var TotalChkBx; var Counter; window.onload = function() { //Get total no. of CheckBoxes in side the GridView. TotalChkBx = parseInt(’<%= this.gvCheckboxes.Rows.Count %>’); //Get total no. of checked CheckBoxes in side the GridView. Counter = 0; } function HeaderClick(CheckBox) { //Get target base & child control. var TargetBaseControl = document.getElementById(’<%= this.gvCheckboxes.ClientID %>’); var TargetChildControl = “chkBxSelect”; //Get all the control of the type INPUT in the base control. var Inputs = TargetBaseControl.getElementsByTagName(”input”); //Checked/Unchecked all the checkBoxes in side the GridView. for(var n = 0; n < Inputs.length; ++n) if(Inputs[n].type == ‘checkbox’ && Inputs[n].id.indexOf(TargetChildControl,0) >= 0) Inputs[n].checked = CheckBox.checked; //Reset Counter Counter = CheckBox.checked ? TotalChkBx : 0; } function ChildClick(CheckBox, HCheckBox) { //get target base & child control. var HeaderCheckBox = document.getElementById(HCheckBox); //Modifiy Counter; if(CheckBox.checked && Counter < TotalChkBx) Counter++; else if(Counter > 0) Counter–; //Change state of the header CheckBox. if(Counter < TotalChkBx) HeaderCheckBox.checked = false; else if(Counter == TotalChkBx) HeaderCheckBox.checked = true; } </script> <asp:GridView ID=”gvCheckboxes” runat=”server” AutoGenerateColumns=”False” OnRowCreated=”gvCheckboxes_RowCreated”> <Columns> <asp:BoundField HeaderText=”S.N.” DataField=”sno”> <HeaderStyle HorizontalAlign=”Center” VerticalAlign=”Middle” Width=”50px” /> <ItemStyle HorizontalAlign=”Center” VerticalAlign=”Middle” Width=”50px” /> </asp:BoundField> <asp:TemplateField HeaderText=”Select”> <ItemTemplate> <asp:CheckBox ID=”chkBxSelect” runat=”server” /> </ItemTemplate> <HeaderStyle HorizontalAlign=”Center” VerticalAlign=”Middle” Width=”50px” /> <ItemStyle HorizontalAlign=”Center” VerticalAlign=”Middle” Width=”50px” /> <HeaderTemplate> <asp:CheckBox ID=”chkBxHeader” onclick=”javascript:HeaderClick(this);” runat=”server” /> </HeaderTemplate> </asp:TemplateField> <asp:TemplateField> <ItemTemplate> <asp:CheckBox ID=”chkBx” runat=”server” /> </ItemTemplate> <ItemStyle HorizontalAlign=”Center” VerticalAlign=”Middle” Width=”50px” /> </asp:TemplateField> </Columns> <RowStyle BackColor=”Moccasin” /> <AlternatingRowStyle BackColor=”NavajoWhite” /> <HeaderStyle BackColor=”DarkOrange” Font-Bold=”True” ForeColor=”White” /> </asp:GridView> protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { BindGridView(); } } protected void BindGridView() { gvCheckboxes.DataSource = GetDataSource(); gvCheckboxes.DataBind(); } protected DataTable GetDataSource() { DataTable dTable = new DataTable(); DataRow dRow = null; Random rnd = new Random(); dTable.Columns.Add(”sno”); for (int n = 0; n < 10; ++n) { dRow = dTable.NewRow(); dRow["sno"] = n + “.”; dTable.Rows.Add(dRow); dTable.AcceptChanges(); } return dTable; } protected void gvCheckboxes_RowCreated(object sender, GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.DataRow && (e.Row.RowState == DataControlRowState.Normal || e.Row.RowState == DataControlRowState.Alternate)) { CheckBox chkBxSelect = (CheckBox)e.Row.Cells[1].FindControl(”chkBxSelect”); CheckBox chkBxHeader = (CheckBox)this.gvCheckboxes.HeaderRow.FindControl(”chkBxHeader”); chkBxSelect.Attributes["onclick"] = string.Format(”javascript:ChildClick(this,’{0}’);”, chkBxHeader.ClientID); } }