我将 JSON 发布到控制器方法，当它尝试将 JSON 数字转换为字节类型时，似乎 ASP.Net MVC 3 中包含的 JsonValueProvider 已损坏。
基本上正在发生的事情是任何需要转换为字节的非空值都是空的，并且我的模型状态有错误，没有错误消息。如返回 JSON 中的问题列表所示。dnbscore 和 region 有错误，但 rating 没有。返回的数据的 dnbscore 和 region 为 null，即使在传递 JSON 时，这些字段也有值。我可以使用自定义模型绑定器来解决这个问题，但我想知道是否有不同的方法可以让 JsonValueProider 像我期望的那样工作。
这是我要构建的对象：
public class APICustomerDetailsDTO
{
public int customerid { get; set; }
[StringLength(30)]
public string customername { get; set; }
public decimal? globalcredit { get; set; }
[Range(0,5)]
public byte? rating { get; set; }
[Range(0, 100)]
public byte? dnbscore { get; set; }
[Range(0, 8)]
public byte? region { get; set; }
[Required]
public bool isnotactive { get; set; }
public string salesperson { get; set; }
[StringLength(30)]
public string newmill_venderid { get; set; }
[StringLength(30)]
public string newmill_supplierid { get; set; }
[StringLength(30)]
public string edi_receiverid { get; set; }
[Required]
public bool edi_invoice { get; set; }
[StringLength(15)]
public string bill_code { get; set; }
}
这是我在发布请求中发送的 JSON：
{"bill_code":"good","customerid":50,"customername":"Ted","dnbscore":80,"edi_invoice":false,"edi_receiverid":null,"globalcredit":null,"isnotactive":false,"newmill_supplierid":null,"newmill_venderid":null,"rating":null,"region":0,"salesperson":null}
我检查模型状态的方法的一部分：
if (!ModelState.IsValid)
{
var issues = ModelState.Where(m => m.Value.Errors.Any())
.Select((m)=> new {field = m.Key, error = m.Value.Errors.FirstOrDefault().ErrorMessage})
.ToArray();
var result = new
{
result = "Failure",
message = "Invalid data received. See issues for details.",
issues = issues,
data = cust
};
返回 JSON：
{"result":"Failure","message":"Invalid data received. See issues for details.","issues":[{"field":"dnbscore","error":""},{"field":"region","error":""}],"data":{"customerid":50,"customername":"Ted","globalcredit":null,"rating":null,"dnbscore":null,"region":null,"isnotactive":false,"salesperson":null,"newmill_venderid":null,"newmill_supplierid":null,"edi_receiverid":null,"edi_invoice":false,"bill_code":"good"}}
为了完整起见，这是我为解决此问题所做的工作：
通过 Darin 提供的信息，我意识到这是一个比字节更大的问题？诠释？转换。对于默认绑定器提供的任何非整数转换，这将是一个问题。因此，我制作了一个自定义活页夹，它可以很好地处理字节、十进制等数字。见下文：
public class APICustomerDetailsDTOBinder : IModelBinder
{
public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
APICustomerDetailsDTO model = (APICustomerDetailsDTO)bindingContext.Model ??
(APICustomerDetailsDTO)DependencyResolver.Current.GetService(typeof(APICustomerDetailsDTO));
bool hasPrefix = bindingContext.ValueProvider.ContainsPrefix(bindingContext.ModelName);
string searchPrefix = (hasPrefix) ? bindingContext.ModelName + "." : "";
int customerid = 0;
int.TryParse(GetValue(bindingContext, searchPrefix, "customerid"), out customerid);
model.customerid = customerid;
string customername = GetValue(bindingContext, searchPrefix, "customername");
if (!String.IsNullOrEmpty(customername))
{ model.customername = customername; }
else
{ model.customername = null; }
decimal globalcredit;
if (decimal.TryParse(GetValue(bindingContext, searchPrefix, "globalcredit"), out globalcredit))
{ model.globalcredit = globalcredit; }
else
{ model.globalcredit = null; }
byte rating;
if (byte.TryParse(GetValue(bindingContext, searchPrefix, "rating"), out rating))
{ model.rating = rating; }
else
{ model.rating = null; }
byte dnbscore;
if (byte.TryParse(GetValue(bindingContext, searchPrefix, "dnbscore"), out dnbscore))
{ model.dnbscore = dnbscore; }
else
{ model.dnbscore = null; }
byte region;
if (byte.TryParse(GetValue(bindingContext, searchPrefix, "region"), out region))
{ model.region = region; }
else
{ model.region = null; }
bool isnotactive;
if (bool.TryParse(GetValue(bindingContext, searchPrefix, "isnotactive"), out isnotactive))
{ model.isnotactive = isnotactive; }
else
{ model.isnotactive = false; }
string salesperson = GetValue(bindingContext, searchPrefix, "salesperson");
if (!String.IsNullOrEmpty(salesperson))
{ model.salesperson = salesperson; }
else
{ model.salesperson = null; }
string newmill_venderid = GetValue(bindingContext, searchPrefix, "newmill_venderid");
if (!String.IsNullOrEmpty(newmill_venderid))
{ model.newmill_venderid = newmill_venderid; }
else
{ model.newmill_venderid = null; }
string newmill_supplierid = GetValue(bindingContext, searchPrefix, "newmill_supplierid");
if (!String.IsNullOrEmpty(newmill_supplierid))
{ model.newmill_supplierid = newmill_supplierid; }
else
{ model.newmill_supplierid = null; }
string edi_receiverid = GetValue(bindingContext, searchPrefix, "edi_receiverid");
if (!String.IsNullOrEmpty(edi_receiverid))
{ model.edi_receiverid = edi_receiverid; }
else
{ model.edi_receiverid = null; }
bool edi_invoice;
if (bool.TryParse(GetValue(bindingContext, searchPrefix, "edi_invoice"), out edi_invoice))
{ model.edi_invoice = edi_invoice; }
else
{ model.edi_invoice = false; }
model.bill_code = GetValue(bindingContext, searchPrefix, "bill_code");
return model;
}
private string GetValue(ModelBindingContext context, string prefix, string key)
{
ValueProviderResult vpr = context.ValueProvider.GetValue(prefix + key);
return vpr == null ? null : vpr.AttemptedValue;
}
private bool GetCheckedValue(ModelBindingContext context, string prefix, string key)
{
bool result = false;
ValueProviderResult vpr = context.ValueProvider.GetValue(prefix + key);
if (vpr != null)
{
result = (bool)vpr.ConvertTo(typeof(bool));
}
return result;
}
}