Hi
I have created a sample which full fill your requriement you need to modify the code according to your need
HTML
<div>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" AutoGenerateEditButton="true"
OnRowCancelingEdit="GridView1_RowCancelingEdit" OnRowEditing="GridView1_RowEditing"
OnRowUpdating="GridView1_RowUpdating">
<Columns>
<asp:TemplateField HeaderText="Start Date">
<ItemTemplate>
<asp:Label ID="lblStartDate" Text='<%# Eval("StartDate") %>' runat="server" />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtStartDate" Text='<%# Eval("StartDate") %>' runat="server"></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="End Date">
<ItemTemplate>
<asp:Label ID="lblEndDate" Text='<%# Eval("EndDate") %>' runat="server" />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtEndDate" Text='<%# Eval("EndDate") %>' AutoPostBack="true" OnTextChanged="TimeSpan"
runat="server"></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Difference Time">
<ItemTemplate>
<asp:Label ID="lblTimeDifference" runat="server" />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtTimeDifference" runat="server"></asp:TextBox>
<asp:HiddenField ID="hfTimeDifference" runat="server" />
</EditItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</div>
<div>
<link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css" />
<link rel="stylesheet" href="/resources/demos/style.css" />
<script type="text/javascript" src="https://code.jquery.com/jquery-1.12.4.js"></script>
<script type="text/javascript" src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
<script type="text/javascript">
$(function () {
$("[id*=txtStartDate]").datepicker({ showSecond: true, dateFormat: 'mm/dd/yy' });
$("[id*=txtEndDate]").datepicker({ showSecond: true, dateFormat: 'mm/dd/yy' });
});
</script>
</div>
C#
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
BindGrid();
}
}
private void BindGrid()
{
DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[3] { new DataColumn("StartDate"), new DataColumn("EndDate"), new DataColumn("Country") });
dt.Rows.Add(DateTime.Now.AddDays(-35).ToShortDateString(), DateTime.Now.AddDays(10).ToShortDateString());
dt.Rows.Add(DateTime.Now.AddDays(-15).ToShortDateString(), DateTime.Now.AddDays(15).ToShortDateString());
dt.Rows.Add(DateTime.Now.AddDays(-45).ToShortDateString(), DateTime.Now.AddDays(3).ToShortDateString());
dt.Rows.Add(DateTime.Now.AddDays(-12).ToShortDateString(), DateTime.Now.AddDays(36).ToShortDateString());
GridView1.DataSource = dt;
GridView1.DataBind();
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
BindGrid();
}
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridView1.EditIndex = -1;
BindGrid();
}
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridView1.EditIndex = -1;
BindGrid();
}
protected void TimeSpan(object sender, EventArgs e)
{
GridViewRow row = (sender as TextBox).NamingContainer as GridViewRow;
string txtStartDate = (row.FindControl("txtStartDate") as TextBox).Text;
string txtEndDate = (row.FindControl("txtEndDate") as TextBox).Text;
TimeSpan timeSpan = Convert.ToDateTime(txtEndDate) - Convert.ToDateTime(txtStartDate);
TextBox txtTimeDifference = (row.FindControl("txtTimeDifference") as TextBox);
txtTimeDifference.Text = timeSpan.ToString();
}
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
If Not Me.IsPostBack Then
BindGrid()
End If
End Sub
Private Sub BindGrid()
Dim dt As New DataTable()
dt.Columns.AddRange(New DataColumn(2) {New DataColumn("StartDate"), New DataColumn("EndDate"), New DataColumn("Country")})
dt.Rows.Add(DateTime.Now.AddDays(-35).ToShortDateString(), DateTime.Now.AddDays(10).ToShortDateString())
dt.Rows.Add(DateTime.Now.AddDays(-15).ToShortDateString(), DateTime.Now.AddDays(15).ToShortDateString())
dt.Rows.Add(DateTime.Now.AddDays(-45).ToShortDateString(), DateTime.Now.AddDays(3).ToShortDateString())
dt.Rows.Add(DateTime.Now.AddDays(-12).ToShortDateString(), DateTime.Now.AddDays(36).ToShortDateString())
GridView1.DataSource = dt
GridView1.DataBind()
End Sub
Protected Sub GridView1_RowEditing(sender As Object, e As GridViewEditEventArgs)
GridView1.EditIndex = e.NewEditIndex
BindGrid()
End Sub
Protected Sub GridView1_RowUpdating(sender As Object, e As GridViewUpdateEventArgs)
GridView1.EditIndex = -1
BindGrid()
End Sub
Protected Sub GridView1_RowCancelingEdit(sender As Object, e As GridViewCancelEditEventArgs)
GridView1.EditIndex = -1
BindGrid()
End Sub
Protected Sub TimeSpan(sender As Object, e As EventArgs)
Dim row As GridViewRow = TryCast(TryCast(sender, TextBox).NamingContainer, GridViewRow)
Dim txtStartDate As String = TryCast(row.FindControl("txtStartDate"), TextBox).Text
Dim txtEndDate As String = TryCast(row.FindControl("txtEndDate"), TextBox).Text
Dim timeSpan__1 As TimeSpan = Convert.ToDateTime(txtEndDate) - Convert.ToDateTime(txtStartDate)
Dim txtTimeDifference As TextBox = TryCast(row.FindControl("txtTimeDifference"), TextBox)
txtTimeDifference.Text = timeSpan__1.ToString()
End Sub
ScreenShot