Hi kaustubhbhat,
The GridView control renders to client is a HTML table. So we can operate it on the client side. However, please note the Gridview will render every postback, so all the change will be restored. The following code is for your reference. I hope it is helpful to you.
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
<script type="text/javascript">
function SetNumberOfRows(textbox)
{
var number = Number(document.getElementById('Text1').value);
var table = document.getElementById('GridView1');
if (table.rows.length > number)
{
for(var i=table.rows.length; i>number;)
{
table.deleteRow(--i);
}
}
else
{
for(var i=table.rows.length; i<number; i++)
{
var row = table.insertRow();
var cell = row.insertCell();
cell.innerText = 'null';
cell = row.insertCell();
cell.innerText = 'null';
}
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="GridView1" runat="server">
</asp:GridView>
<br />
<input id="Text1" style="position: static" type="text" />
<input id="Button1" onclick="SetNumberOfRows()" style="position: static" type="button"
value="button" /></div>
</form>
</body>
</html>
****************** code behind file
DataTable myTable;
protected void Page_Load(object sender, EventArgs e)
{
myTable = new DataTable();
myTable.Columns.Add("ID", typeof(Int32));
myTable.Columns.Add("Name", typeof(String));
myTable.Rows.Add(1,"aaa");
myTable.Rows.Add(2, "bbb");
myTable.Rows.Add(3, "ccc");
GridView1.DataSource = myTable;
GridView1.DataBind();
}