update operation for dynamic textbox in mvc

[HttpPost]

[ValidateInput(false)]

public ActionResult Editproduct(string[] TestBoxStringList, FormCollection form,string[] stringList1, string[] textboxlist1, string[] textboxlist2, Product model, int id, HttpPostedFileBase image1, HttpPostedFileBase image2, HttpPostedFileBase image3, HttpPostedFileBase image4)

{

if (ModelState.IsValid)

{

string ImgPath1 = null;

if (image1 != null)

{

var x = (from c in context.productdetail where c.Id ==id select c).FirstOrDefault();

//x.TextBox1 = null;

//x.TextBox2 = null;

string path1 = Server.MapPath("~/ProductImage/" + x.Photo1);

FileInfo fi = new FileInfo(path1);

if (fi.Exists)

fi.Delete();

var Filename = Path.GetFileName(image1.FileName);

Random RandomClass = new Random();

int randmno = RandomClass.Next(345678);

string trfile1 = randmno.ToString() + Filename.ToString();

var path2 = "~/ProductImage/" + trfile1;

image1.SaveAs(Server.MapPath(path2));

ImgPath1 = trfile1;

model.Photo1 = trfile1;

}

if (model.Photo1 == null)

{

model.Photo1 = form["photo1"].ToString();

}

string ImgPath2 = null;

if (image2 != null)

{

var x2 = (from c in context.productdetail where c.Id == id select c).FirstOrDefault();

string path3 = Server.MapPath("~/ProductImage/" + x2.Photo1);

FileInfo fi = new FileInfo(path3);

if (fi.Exists)

fi.Delete();

var Filename = Path.GetFileName(image2.FileName);

Random RandomClass = new Random();

int randmno = RandomClass.Next(345678);

string trfile2 = randmno.ToString() + Filename.ToString();

var path4 = "~/ProductImage/" + trfile2;

image2.SaveAs(Server.MapPath(path4));

ImgPath2 = trfile2;

model.Photo2 = trfile2;

}

if (model.Photo2 == null)

{

model.Photo2 = form["photo2"].ToString();

}

string ImgPath3 = null;

if (image3 != null)

{

var x3 = (from c in context.productdetail where c.Id == id select c).FirstOrDefault();

string path5 = Server.MapPath("~/ProductImage/" + x3.Photo3);

FileInfo fi = new FileInfo(path5);

if (fi.Exists)

fi.Delete();

var Filename = Path.GetFileName(image3.FileName);

Random RandomClass = new Random();

int randmno = RandomClass.Next(345678);

string trfile3 = randmno.ToString() + Filename.ToString();

var path6 = "~/ProductImage/" + trfile3;

image3.SaveAs(Server.MapPath(path6));

ImgPath3 = trfile3;

model.Photo3 = trfile3;

}

if (model.Photo3 == null)

{

model.Photo3 = form["photo3"].ToString();

}

string ImgPath4 = null;

if (image4 != null)

{

var x4 = (from c in context.productdetail where c.Id == id select c).FirstOrDefault();

string path7 = Server.MapPath("~/ProductImage/" + x4.Photo4);

FileInfo fi = new FileInfo(path7);

if (fi.Exists)

fi.Delete();

var Filename = Path.GetFileName(image4.FileName);

Random RandomClass = new Random();

int randmno = RandomClass.Next(345678);

string trfile4 = randmno.ToString() + Filename.ToString();

var path8 = "~/ProductImage/" + trfile4;

image4.SaveAs(Server.MapPath(path8));

ImgPath4 = trfile4;

model.Photo4 = trfile4;

}

if (model.Photo4 == null)

{

model.Photo4 = form["photo4"].ToString();

//obj.Photo4 = model.Photo4;

}

var textboxid1 = "";

var Newtextboxid1 = "";

if (TestBoxStringList != null)

{

}

if (textboxlist1 != null)

{

List Newlist = new List(textboxlist1);

foreach (var item in Newlist)

{

if (item != "")

{

Newtextboxid1 += item.ToString() + ",";

}

}

Newtextboxid1 = Newtextboxid1.Remove(Newtextboxid1.Length - 1, 1);

}

if ( TestBoxStringList != null)

{

List list1 = new List(TestBoxStringList);

foreach (var item in list1)

{

if (item != "")

{

textboxid1 += item.ToString() + ",";

}

}

textboxid1 = textboxid1.Remove(textboxid1.Length - 1, 1);

}

var textboxid2 = "";

var Newtextboxid2 = "";

if (textboxlist2 != null)

{

List Newlist2 = new List(textboxlist2);

foreach (var Newitem in Newlist2)

{

if (Newitem != "")

{

Newtextboxid2 += Newitem.ToString() + ",";

}

}

Newtextboxid2 = Newtextboxid2.Remove(Newtextboxid2.Length - 1, 1);

}

if (stringList1 != null)

{

List list2 = new List(stringList1);

foreach (var item in list2)

{

if (item != "")

{

textboxid2 += item.ToString() + ",";

}

}

textboxid2 = textboxid2.Remove(textboxid2.Length - 1, 1);

}

//model.TextBox1 = null;

//model.TextBox2 = null;

if (Newtextboxid1!=null && Newtextboxid1!="")

{

textboxid1 = textboxid1 + "," + Newtextboxid1;

textboxid1 = textboxid1.TrimStart(',');

}

if (Newtextboxid2 != null && Newtextboxid2 !="")

{

textboxid2 = textboxid2 +"," + Newtextboxid2;

textboxid2 = textboxid2.TrimStart(',');

}

else

{

}

model.TextBox1 = textboxid1;

model.TextBox2 = textboxid2;

//text = text.TrimStart(arr);

var currentProduct = context.productdetail.Find(model.Id);

context.Entry(currentProduct).CurrentValues.SetValues(model);

context.SaveChanges();

return RedirectToAction("AddProducts", "Decorika");

}

return RedirectToAction("Editproduct", "Decorika");

}