Update data in Codefirst approach in asp.net entity framework

Question

Hello Experts..

 

my scenario is update data in Code First approach in asp.net EF and I am using gridview to do CRUD operation..... I am stuck in Update operation...

 

I am using this scenario....

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridViewRow row = GridView1.Rows[e.RowIndex];
TextBox txtName = row.FindControl("txtName") as TextBox;
TextBox txtDesignation = row.FindControl("txtDesignation") as TextBox;
using (DatabaseContext context = new DatabaseContext())
{
int Id = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Value);
Designation obj = context.Designations.First(x => x.Id == Id);
obj.Name = txtName.Text;
obj.Designationn = txtDesignation.Text;
db.Entry(modal).State = EntityState.Modified;
context.SaveChanges();
bindGridview();
}
}