Why transaction does not work? Works only first .savechanges(); - asp.net-mvc

Question

I need to do 2 savechanges. But first of them does not work. Ready method has simple view that says Thank you, #Viewbag.OrderName
Сontroller
public class Some : Controller
{
private AppDbContext context;
public Some(AppDbContext ctx)
{
context = ctx;
}
[Httpost]
public ActionResult Buy(int? id, string Price,Order order)
{
if (id == null) return RedirectToAction("Index");
using (var transaction = context.Database.BeginTransaction())
{
context.Orders.Add(order)
context.SaveChanges();
if(Price!=null)
{var ty=context.Phones.Where(p =>
p.PhoneId==id).FirstOrDefault();
ty.Price1=Price+150;
}
context.SaveChanges();
transaction.Commit();
}
return View("Buy");
}
public ActionResult Ready(int? id, string OrderName)
{
ViewBag.PhoneId = id;
ViewBag.OrderName = OrderName;
return View();
}
}
}
Startup
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<AppDbContext>(options =>
options.UseSqlServer(Configuration["Data:AppDb:ConnectionString"]));
services.AddTransient<Some>();}
Context class
public class AppDbContext : DbContext
{
public AppDbContext(DbContextOptions<AviaAppDbContext> options)
: base(options)
{
}
public DbSet<Phone> Phones { get; set; }
public DbSet<Order> Orders { get; set; }
appsettings
"AllowedHosts": "*",
"Data": {
"AppDb": {
"ConnectionString": "Server=(localdb)\\MSSQLLocalDB;Database=AppDb;Trusted_Connection=True;MultipleActiveResultSets=true"
}
Added view for more information
View 1
foreach p in Model
<form method="post">
<td class="pricelight"><input type="radio" name="price"value="#p.PriceLight.ToString("")"/>#p.PriceLight.ToString("")</td>
<td class="fromtabletime"><input type="radio" name="price"value="#p.PriceOk.ToString("")/>#p.PriceOk.ToString("")</td>
<td class="totable"><input type="radio" name="price"value="#p.PriceHigh.ToString("")/>#p.PriceHigh.ToString("")</td>
<td class="button13"><button type="submit" asp-action="Buy" asp-route-id="#p.PhoneId" asp-controller="Home">Next</button></td>
</form>
View 2
#using System.Linq;
#using System;
#model List<Searchphone>
#{
ViewBag.Title = "PhoneId";
}
<h2 class="orderinformation">Order Data</h2>
<form method="post" class="formpass" asp-action="Ready" asp-controller="Some">
<input type="hidden" id="PhoneId"value="#ViewBag.PhoneId" name="PhoneId">
<label for="OrderSurName">Surname</label><br>
<input type="text" placeholder="Enter Surname" name="OrderSurName" required><br>
<label for="OrderName">Имя</label><br>
<input type="text" placeholder="Enter Name" name="OrderName" required><br>
<button type="submit" class="button7">Next</button>
</form>
I have checked it without Transaction. It works the same. I can not make changes in two tables,one context. What is my mistake?

Answer 1

Your AppDbContext doesn't have a parameterless constructor, and you are trying to invoke one in the using statement. Also, you already are injecting the DbContext with DI so its already initialized and ready to use. With that said you don't need to create a new instance of the context, just use the existing one that you already passed in trough DI.
Hope it helps

Answer 2

If you want to edit Phones data which PhoneId equals to the id parameter, you need change
context.Price1=Price+150; to ty.Price1=Price+150;
More code as follow:
[Httpost]
public ActionResult Buy(int? id, string Price,Order order)
{
if (id == null) return RedirectToAction("Index");
using (var transaction = context.Database.BeginTransaction())
{
context.Orders.Add(order)
context.SaveChanges();
if(Price!=null)
{var ty=context.Phones.Where(p =>
p.PhoneId==id).FirstOrDefault();
ty.Price1=Price+150;
}
context.SaveChanges();
transaction.Commit();
}
return View("Buy");
}