Calculate End Date based on specified Day and Current Date in ASP.Net GridView using C# and VB.Net

Hi irshad1231,

Refer below sample.

HTML

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" OnRowDataBound="GridView1_RowDataBound1">
    <Columns>
        <asp:TemplateField HeaderText="StartDate" SortExpression="StartDate">
            <ItemTemplate>
                <asp:Label ID="Label1" runat="server" Text='<%# Convert.ToDateTime(Eval("StartDate")).ToString("yyyy-MM-dd") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="LeavDays" SortExpression="LeavDays">
            <ItemTemplate>
                <asp:Label ID="Label2" runat="server" Text='<%# Bind("LeavDays") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="enddate">
            <ItemTemplate>
                <asp:Label ID="lbduedate" runat="server" Text="Label"></asp:Label></ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[] { new DataColumn("StartDate", typeof(DateTime)), new DataColumn("LeavDays", typeof(int)), new DataColumn("End Date", typeof(DateTime)) });
        dt.Rows.Add(DateTime.Now, 1);
        dt.Rows.Add(DateTime.Now, 2);
        dt.Rows.Add(DateTime.Now, 3);
        dt.Rows.Add(DateTime.Now, 4);
        dt.Rows.Add(DateTime.Now, 5);
        this.GridView1.DataSource = dt;
        this.GridView1.DataBind();
    }
}

protected void GridView1_RowDataBound1(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        DateTime startDate = Convert.ToDateTime((e.Row.FindControl("Label1") as Label).Text);
        int leaveNo = Convert.ToInt32((e.Row.FindControl("Label2") as Label).Text);
        e.Row.Cells[2].Text = startDate.AddDays(leaveNo - 1).ToString("yyyy-MM-dd");
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As DataTable = New DataTable()
        dt.Columns.AddRange(New DataColumn() {New DataColumn("StartDate", GetType(DateTime)), New DataColumn("LeavDays", GetType(Integer)), New DataColumn("End Date", GetType(DateTime))})
        dt.Rows.Add(DateTime.Now, 1)
        dt.Rows.Add(DateTime.Now, 2)
        dt.Rows.Add(DateTime.Now, 3)
        dt.Rows.Add(DateTime.Now, 4)
        dt.Rows.Add(DateTime.Now, 5)
        Me.GridView1.DataSource = dt
        Me.GridView1.DataBind()
    End If
End Sub

Protected Sub GridView1_RowDataBound1(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
    If e.Row.RowType = DataControlRowType.DataRow Then
        Dim startDate As DateTime = Convert.ToDateTime((TryCast(e.Row.FindControl("Label1"), Label)).Text)
        Dim leaveNo As Integer = Convert.ToInt32((TryCast(e.Row.FindControl("Label2"), Label)).Text)
        e.Row.Cells(2).Text = startDate.AddDays(leaveNo - 1).ToString("yyyy-MM-dd")
    End If
End Sub

Screenshot