jQuery Ajax POST到ASP.NET

Question

我有這個ajax調用，並且正在向其中傳遞一個看起來像["ANC0001-Pin Lot"]的數組，然后嘗試將其傳遞給asp.net。 我可以在網絡控制台中的“請求有效負載”下看到我的陣列在那里。

這是jQuery：

$.ajax({
    type: "POST",
    url: "/vendorProject/api/connection/updateVendorItem",
    data: JSON.stringify({ edittedItems: editHolder }),
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (data) {
        alert('success');
    },
    failure: function (errMsg) {
        alert('failed');
    }
});

這是我的ASP.NET控制器：

public List<VendorUpdateClass> updateVendorItem(Array edittedItems)
{
    ConnectionClass jobs = new ConnectionClass();
    return jobs.updateVendors(edittedItems);
}

updateVendors方法：

 public List<VendorUpdateClass> updateVendors(Array items)
{
    VendorUpdateCell = new List<VendorUpdateClass>();
    VendorUpdateClass vendorUpdatedItem = new VendorUpdateClass();

    for (int i = 0; i < items.Length; i++ ){
        vendorUpdatedItem.job = "aaa";
        vendorUpdatedItem.task = "bbb";
        vendorUpdatedItem.vendor = "ccc";

        VendorUpdateCell.Add(vendorUpdatedItem);
    }

    return VendorUpdateCell;
}

我正在獲取500內部服務器錯誤：

    {  
       "Message":"An error has occurred.",
       "ExceptionMessage":"Object reference not set to an instance of an object.",
       "ExceptionType":"System.NullReferenceException",
       "StackTrace":"   at VendorProject.Models.ConnectionClass.updateVendors(Array items)\r\n   
at lambda_method(Closure , Object , Object[] )\r\n   
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\r\n   
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary 2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter 1.GetResult()\r\n   
at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n
--- End of stack trace from previous location where exception was thrown ---\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter 1.GetResult()\r\n   
at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n
--- End of stack trace from previous location where exception was thrown ---\r\n
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter 1.GetResult()\r\n   at System.Web.Http.Controllers.AuthenticationFilterResult.<ExecuteAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter 1.GetResult()\r\n   
at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"
    }

沒有循環，它確實起作用。 當我放入循環時，這給了我500錯誤。 為什么要這樣做，我該如何解決？

Answer 1

嘗試這個：

public List<VendorUpdateClass> updateVendorItem(string[] edittedItems)
    {
        ConnectionClass jobs = new ConnectionClass();
        return jobs.updateVendors(edittedItems);
    }

您也可以嘗試用List<string>替換字符串數組

我還發現了如何不使用表單將字符串數組發布到ASP.NET MVC Controller？

也許你在那里可以得到一些啟發

Answer 2

現在，您要發布一個對象，該對象包含一個名為edittedItems的屬性（注意：您可能是指帶有一個“ t”的editedItems ），其值是一個數組。

將此與您期望僅一個數組的控制器操作進行對比。 您需要將AJAX請求更改為僅發布一個數組：

data: JSON.stringify(editHolder)

然后就像@JOSEFtw所提到的 ，您可能應該使用string[]或List<string>而不是Array 。

Answer 3

現在嘗試此方法，我已經更新了id，因為我可能由於空引用items.Length而崩潰。

public List<VendorUpdateClass> updateVendors(Array items)
        {
            VendorUpdateCell = new List<VendorUpdateClass>();
            VendorUpdateClass vendorUpdatedItem = new VendorUpdateClass();

            if (items == null && items.Length < 1)
                return VendorUpdateCell;

            for (int i = 0; i < items.Length; i++)
            {
                vendorUpdatedItem.job = "aaa";
                vendorUpdatedItem.task = "bbb";
                vendorUpdatedItem.vendor = "ccc";

                VendorUpdateCell.Add(vendorUpdatedItem);
            }

            return VendorUpdateCell;
        }

在for循環之前寫這行

if (items == null && items.Length < 1) return VendorUpdateCell;