Question

我想控制何时回复错误消息和成功消息，但我总是收到错误消息：

以下是我要做的事情：

 $.ajax({
                type: "POST",
                data: formData,
                url: "/Forms/GetJobData",
                dataType: 'json',
                contentType: false,
                processData: false,

                success: function (response) {                    
                   alert("success!") 
                },
                error: function (response) {
                   alert("error") // I'm always get this.
                }

            });

控制器：

         [HttpPost]
            public ActionResult GetJobData(Jobs jobData)
            {

              var mimeType = jobData.File.ContentType;
              var isFileSupported = AllowedMimeTypes(mimeType);

             if (!isFileSupported){        
                     //  Error
                    Response.StatusCode = (int)HttpStatusCode.BadRequest;
                    return Content("The attached file is not supported", MediaTypeNames.Text.Plain);    
             }
            else
              {
                    //  Success
                    Response.StatusCode = (int)HttpStatusCode.OK;
                    return Content("Message sent!", MediaTypeNames.Text.Plain);     

               }   

            }

Answer 1

 $.ajax({
    type: "POST",
    data: formData,
    url: "/Forms/GetJobData",
    dataType: 'json',
    contentType: false,
    processData: false,               
    success: function (response) {
        if (response.success) {
            alert(response.responseText);
        } else {
            // DoSomethingElse()
            alert(response.responseText);
        }                          
    },
    error: function (response) {
        alert("error!");  // 
    }

});

<强>控制器：

[HttpPost]
public ActionResult GetJobData(Jobs jobData)
{
    var mimeType = jobData.File.ContentType;
    var isFileSupported = IsFileSupported(mimeType);

    if (!isFileSupported){        
         //  Send "false"
        return Json(new { success = false, responseText = "The attached file is not supported." }, JsonRequestBehavior.AllowGet);
    }
    else
    {
        //  Send "Success"
        return Json(new { success = true, responseText= "Your message successfuly sent!"}, JsonRequestBehavior.AllowGet);
    }   
}

<强> ---补充：---

基本上你可以用这种方式发送多个参数：

控制器：

 return Json(new { 
                success = true,
                Name = model.Name,
                Phone = model.Phone,
                Email = model.Email                                
            }, 
            JsonRequestBehavior.AllowGet);

HTML：

<script> 
     $.ajax({
                type: "POST",
                url: '@Url.Action("GetData")',
                contentType: 'application/json; charset=utf-8',            
                success: function (response) {

                   if(response.success){ 
                      console.log(response.Name);
                      console.log(response.Phone);
                      console.log(response.Email);
                    }


                },
                error: function (response) {
                    alert("error!"); 
                }
            });

Answer 2

使用Json类而不是Content，如下所示：

    //  When I want to return an error:
    if (!isFileSupported)
    {
        Response.StatusCode = (int) HttpStatusCode.BadRequest;
        return Json("The attached file is not supported", MediaTypeNames.Text.Plain);
    }
    else
    {
        //  When I want to return sucess:
        Response.StatusCode = (int)HttpStatusCode.OK; 
        return Json("Message sent!", MediaTypeNames.Text.Plain);
    }

还设置contentType：

contentType: 'application/json; charset=utf-8',

Answer 3

当您从服务器返回值到jQuery的Ajax调用时，您还可以使用以下代码指示服务器错误：

return StatusCode(500, "My error");

或

return StatusCode((int)HttpStatusCode.InternalServerError, "My error");

或

Response.StatusCode = (int)HttpStatusCode.InternalServerError;
return Json(new { responseText = "my error" });

除Http Success代码外的其他代码（例如200 [OK]）将触发客户端（ajax）中error:前面的功能。

您可以通过以下方式进行ajax调用：

$.ajax({
        type: "POST",
        url: "/General/ContactRequestPartial",
        data: {
            HashId: id
        },
       success: function (response)  {
            console.log("Custom message : " + response.responseText);
        }, //Is Called when Status Code is 200[OK] or other Http success code
        error: function (jqXHR, textStatus, errorThrown)  {
            console.log("Custom error : " + jqXHR.responseText + " Status: " + textStatus + " Http error:" + errorThrown);
        }, //Is Called when Status Code is 500[InternalServerError] or other Http Error code
        })

此外，您还可以从jQuery方面处理不同的HTTP错误，例如：

$.ajax({
        type: "POST",
        url: "/General/ContactRequestPartial",
        data: {
            HashId: id
        },
        statusCode: {
            500: function (jqXHR, textStatus, errorThrown)  {
                console.log("Custom error : " + jqXHR.responseText + " Status: " + textStatus + " Http error:" + errorThrown);
            501: function (jqXHR, textStatus, errorThrown)  {
                console.log("Custom error : " + jqXHR.responseText + " Status: " + textStatus + " Http error:" + errorThrown);
            }
        })

statusCode:对于要为从服务器返回的不同状态代码调用不同功能的情况很有用。

您可以在此处查看不同的Http状态代码列表：Wikipedia

其他资源：

Answer 4

当您从 Controller 返回错误请求时，会触发全局异常。可能是客户端显示了错误页面，所以jquery得到200响应。

解决方案 1：

控制器

[HttpPost]
public ActionResult FooAction(string id, string[] orderFields)
{
    bool hasError = true; //TODO: Validation

    if (hasError)
    {
       Response.Clear();
       Response.TrySkipIisCustomErrors = true; //the magic
       Response.StatusCode = (int)HttpStatusCode.InternalServerError;

       return Json(new { success = false, message = "test error", status = 500 });
    }
    else
    {
       return Json(new { success = true, message = "ok", status = 200 });
    }
}

查看：

<script type="text/javascript">
    $.ajax({
        type: "POST",
        url: url,
        data: { orderFields: order },
        success: function (response) {
            if (response.success) {
                alert("Ok");
            }
        },
        error: function (xhr, status, error) {
            if (xhr.responseText != "") {
                var err = JSON.parse(xhr.responseText);
                if (err.status == 440) {
                    alert("Session expired");
                }
                else {
                    alert(err.message);
                }
            }
            else {
                alert("Crash");
            }
        }
    });
</script>

解决方案 2： （更优雅）
创建自定义属性

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Net;
using System.Web.Mvc;

public class ExceptionJsonMvcAttribute : FilterAttribute, IExceptionFilter
{
    public virtual void OnException(ExceptionContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("filterContext");
        }

        if (context.Exception == null)
            return;

        int status;
        string message;
        var ex = context.Exception;
        var exceptionType = ex.GetType();
        if (exceptionType == typeof(UnauthorizedAccessException))
        {
            var exAccess = (UnauthorizedAccessException)ex;
            message = exAccess.Message;
            status = (int)HttpStatusCode.Unauthorized;
        }
        else if (exceptionType == typeof(SqlException))
        {
            var exSql = (SqlException)ex;
            message = GetDbMessage(exSql);
            status = (int)HttpStatusCode.BadRequest;
        }
        else if (exceptionType == typeof(KeyNotFoundException))
        {
            var exNotFound = (KeyNotFoundException)ex;
            message = exNotFound.Message;
            status = (int)HttpStatusCode.NotFound;
        }
        else
        {
            message = ex.Message;
            status = (int)HttpStatusCode.InternalServerError;
        }


        string json = ""; // TODO: Json(new { success = false, message = message, status = status });
        context.ExceptionHandled = true;
        context.HttpContext.Response.Clear();
        context.HttpContext.Response.TrySkipIisCustomErrors = true;
        context.HttpContext.Response.StatusCode = status;
        context.HttpContext.Response.ContentType = "application/json";
        context.HttpContext.Response.Write(json);
    }

    private string GetDbMessage(SqlException exSql)
    {
        //TODO: Remove generic from database

        return "DataBase Error see log";
    }
}

注意 ApiController 使用 System.Net.Http 而不是 System.Web.Mvc

控制器：

[ExceptionJsonMvc]
[HttpPost]
public ActionResult FooAction(string id, string[] orderFields)
{
    bool hasError = true; //TODO: Validation

    if (hasError)
    {
       throw new Exception("test error");
    }
    else
    {
       return Json(new { success = true, message = "ok" });
    }
}

Jquery Ajax，从mvc.net控制器返回成功/错误

4 个答案: