添加项目通过AJAX

Question

动态地列出模型我有下面的代码，我想选择的值添加到列表model.SelectedPayCodes每次用户从下拉菜单中选择并点击“添加”

控制器

[HttpPost] 
public PartialViewResult AddPayCode(ReferralModel model, string SelectedPayCode) 
{ 
    var payCode = _employeeService.GetPayCodeById(Convert.ToInt32(SelectedPayCode)); 

    model.Add(payCode); 
    return PartialView("_PayCodesPartial",model); 
} 

模型

public class ReferralModel 
    { 
     public Customer Customer { get; set; } 
     public Employee Employee { get; set; } 
     public List<PayCode> PayCodes { get; set; } // List of paycodes 
     public List<PayCode> PayCodesList { get; set; } // List of 'selected' paycodes 
     public SelectListItem SelectedPayCode { get; set; } // current selected paycode 

     public Referral Referral { get; set; } 

     public ReferralModel() 
     { 
      PayCodesList = new List<PayCode>(); 
     } 

     // Step 3 - Add Paycode is done here. 
     public void Add(PayCode payCode) 
     { 
      PayCodesList.Add(payCode); 
     } 
    } 

VIEW - Create.cshtml

@using (Ajax.BeginForm("AddPayCode", "Referral", 
    new AjaxOptions() 
    { 
     HttpMethod = "POST", 
     InsertionMode = InsertionMode.InsertAfter, 
     UpdateTargetId = "PayCodes", 
    })) 
    { 
     @Html.AntiForgeryToken() 
     @Html.ValidationSummary() 
     <!-- payCodes input--> 
     <div class="control-group col-lg-6"> 
      <label class="control-label">Product</label> 
      <div class="controls"> 
       <!-- Step 1 + Choose PayCode Here --> 
       @Html.DropDownListFor(model => model.SelectedPayCode, new SelectList(Model.PayCodes.ToList(), "Id", "Description"), "- Select -") 
       <input type="submit" value="Add" /> 

      </div> 
     </div> 

     <!-- pay codes list --> 
     <div id="PayCodes"> 
     </div> 
    } 

VIEW - _PayCodesPartial.cshtml

@model Zenwire.Models.ReferralModel 

@if (Model.PayCodesList != null) 
{ 
    foreach (var item in Model.PayCodesList) 
    { 
     string.Format("{0} - {1}", item.Code, item.Description); 
    } 
} 

这个问题似乎是每当一个新的项目添加列表为空一次不保留它的前一个选择。

Answer 1

试试这个。我使用会话状态

public PartialViewResult AddPayCode(ReferralModel model, string SelectedPayCode) 
    { 
     var payCode = _employeeService.GetPayCodeById(Convert.ToInt32(SelectedPayCode)); 

     model.PayCodesList = GetPayCodes(); 
     model.Add(payCode); 
     Session["paycodes"] = model.PayCodesList; 
     return PartialView("_PayCodesPartial",model); 
    } 

    private List<PayCode> GetPayCodes() 
    { 
     List<PayCode> payCodes = (List<PayCode>)Session["paycodes"]; 
     if (payCodes == null) 
     { 
      payCodes = new List<PayCode>(); 
      Session["paycodes"] = paycode; 
     } 
     return payCodes; 
    }