[SapnaVishwas]

HTML

C# Code

using System;
using System.Web.UI.WebControls;
using System.Data;
using System.Linq;
using System.Configuration;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            this.BindGrid();
        }
    }
    private void BindGrid()
    {
        SqlCommand cmd = new SqlCommand("SELECT top 10 CustomerId, ContactName, Country FROM Customers");
        gvCustomers.DataSource = this.ExecuteQuery(cmd, "SELECT");
        gvCustomers.DataBind();
    }
    private DataTable ExecuteQuery(SqlCommand cmd, string action)
    {
        string conString = ConfigurationManager.ConnectionStrings["constring"].ConnectionString;
        using (SqlConnection con = new SqlConnection(conString))
        {
            cmd.Connection = con;
            switch (action)
            {
                case "SELECT":
                    using (SqlDataAdapter sda = new SqlDataAdapter())
                    {
                        sda.SelectCommand = cmd;
                        using (DataTable dt = new DataTable())
                        {
                            sda.Fill(dt);
                            return dt;
                        }
                    }
                case "UPDATE":
                    con.Open();
                    cmd.ExecuteNonQuery();
                    con.Close();
                    break;
            }
            return null;
        }
    }

    protected void Update(object sender, EventArgs e)
    {
        foreach (GridViewRow row in gvCustomers.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                bool isChecked = row.Cells[0].Controls.OfType().FirstOrDefault().Checked;
                if (isChecked)
                {
                    SqlCommand cmd = new SqlCommand("UPDATE Customers SET ContactName = @ContactName, Country = @Country WHERE CustomerId = @CustomerId");
                    cmd.Parameters.AddWithValue("@ContactName", row.Cells[1].Controls.OfType().FirstOrDefault().Text);
                    cmd.Parameters.AddWithValue("@Country", row.Cells[2].Controls.OfType().FirstOrDefault().SelectedItem.Value);
                    cmd.Parameters.AddWithValue("@CustomerId", gvCustomers.DataKeys[row.RowIndex].Value);
                    this.ExecuteQuery(cmd, "SELECT");
                }
            }
        }
        btnUpdate.Visible = false;
        this.BindGrid();
    }
    protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            SqlCommand cmd = new SqlCommand("SELECT DISTINCT(Country) FROM Customers");
            DropDownList ddlCountries = (e.Row.FindControl("ddlCountries") as DropDownList);
            ddlCountries.DataSource = this.ExecuteQuery(cmd, "SELECT");
            ddlCountries.DataTextField = "Country";
            ddlCountries.DataValueField = "Country";
            ddlCountries.DataBind();
            string country = (e.Row.FindControl("lblCountry") as Label).Text;
            ddlCountries.Items.FindByValue(country).Selected = true;
        }
    }
    protected void OnCheckedChanged(object sender, EventArgs e)
    {
        bool isUpdateVisible = false;
        CheckBox chk = (sender as CheckBox);
        if (chk.ID == "chkAll")
        {
            foreach (GridViewRow row in gvCustomers.Rows)
            {
                if (row.RowType == DataControlRowType.DataRow)
                {
                    row.Cells[0].Controls.OfType().FirstOrDefault().Checked = chk.Checked;
                }
            }
        }
        CheckBox chkAll = (gvCustomers.HeaderRow.FindControl("chkAll") as CheckBox);
        chkAll.Checked = true;
        foreach (GridViewRow row in gvCustomers.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                bool isChecked = row.Cells[0].Controls.OfType().FirstOrDefault().Checked;
                for (int i = 1; i < row.Cells.Count; i++)
                {
                    row.Cells[i].Controls.OfType().FirstOrDefault().Visible = !isChecked;
                    if (row.Cells[i].Controls.OfType().ToList().Count > 0)
                    {
                        row.Cells[i].Controls.OfType().FirstOrDefault().Visible = isChecked;
                    }
                    if (row.Cells[i].Controls.OfType().ToList().Count > 0)
                    {
                        row.Cells[i].Controls.OfType().FirstOrDefault().Visible = isChecked;
                    }
                    if (isChecked && !isUpdateVisible)
                    {
                        isUpdateVisible = true;
                    }
                    if (!isChecked )
                    {
                        chkAll.Checked = false;
                    }
                }
            }
        }
        btnUpdate.Visible = isUpdateVisible;
    }
}