Работает

SushiBar/SushiBarClientApp/Controllers/HomeController.cs

@@ -112,12 +112,12 @@ namespace SushiBarClientApp.Controllers
         [HttpGet]
         public IActionResult Create()
         {
-            ViewBag.Products =
-            APIClient.GetRequest<List<SushiViewModel>>("api/main/getproductlist");
+            ViewBag.Sushis =
+            APIClient.GetRequest<List<SushiViewModel>>("api/main/getsushilist");
             return View();
         }
         [HttpPost]
-        public void Create(int product, int count)
+        public void Create(int sushi, int count)
         {
             if (APIClient.Client == null)
             {
@@ -131,17 +131,17 @@ namespace SushiBarClientApp.Controllers
             OrderBindingModel
             {
                 ClientId = APIClient.Client.Id,
-                SushiId = product,
+                SushiId = sushi,
                 Count = count,
-                Sum = Calc(count, product)
+                Sum = Calc(count, sushi)
             });
             Response.Redirect("Index");
         }
         [HttpPost]
-        public double Calc(int count, int product)
+        public double Calc(int count, int sushi)
         {
             var prod =
-            APIClient.GetRequest<SushiViewModel>($"api/main/getproduct?productId={product}"
+            APIClient.GetRequest<SushiViewModel>($"api/main/getsushi?sushiId={sushi}"
             );
             return count * (prod?.Price ?? 1);
         }

SushiBar/SushiBarClientApp/Views/Home/Create.cshtml

@@ -8,7 +8,7 @@
     <div class="row">
         <div class="col-4">Изделие:</div>
         <div class="col-8">
-            <select id="product" name="product" class="form-control" aspitems="@(new SelectList(@ViewBag.Products,"Id", "ProductName"))"></select>
+            <select id="sushi" name="sushi" class="form-control" aspitems="@(new SelectList(@ViewBag.sushis,"Id", "SushiName"))"></select>
         </div>
     </div>
     <div class="row">
@@ -26,13 +26,12 @@
     <div class="row">
         <div class="col-8"></div>
         <div class="col-4">
-            <input type="submit" value="Создать" class="btn
-btn-primary" />
+            <input type="submit" value="Создать" class="btnbtn-primary" />
         </div>
     </div>
 </form>
 <script>
-    $('#product').on('change', function () {
+    $('#sushi').on('change', function () {
         check();
     });
     $('#count').on('change', function () {
@@ -40,11 +39,11 @@ btn-primary" />
     });
     function check() {
         var count = $('#count').val();
-        var product = $('#product').val();
-        if (count && product) {
+        var sushi = $('#sushi').val();
+        if (count && sushi) {
             $.ajax({
                 method: "POST",
-                url: "/Home/Calc", data: { count: count, product: product },
+                url: "/Home/Calc", data: { count: count, sushi: sushi },
                 success: function (result) {
                     $("#sum").val(result);
                 }