jquery - 将 json 数组发送到 ashx 处理程序

Question

我有这段代码，当我执行它时，它一直显示相同的错误:无效的 JSON 原语:标题。

客户端:

        var title = new Array();

        ...

        for (var i = 0; i < names.length; ++i) {
            title[i] = '{ "titulo' + i + ':"' + names[i] + '"}';
        }

        $("#gif").show();

        $.ajax({
            async: true,
            contentType: 'application/json; charset=utf-8',
            dataType: 'json',
            type: "POST",
            data: { titles: title },
            url: "../handlers/saveUpload.ashx",
            success: function (msg) {                    
                $("#gif").hide();
            }
        });

服务器端:

        context.Response.ContentType = "application/json";
        var data = context.Request;
        var sr = new StreamReader(data.InputStream);
        var stream = sr.ReadToEnd();

        var javaScriptSerializer = new JavaScriptSerializer();

        var arrayOfStrings = javaScriptSerializer.Deserialize<string[]>(stream);

        foreach (var item in arrayOfStrings)
        {
            context.Response.Write(item);
        }

问候

Answer 1

在这篇文章中解决:convert array to json and receive in ashx handler

string[] is not a valid generic type for that operation; string doesn't have a parameterless constructor so when the serialiser tries to new one up, it fails. Besides, you already have a string from sr.ReadToEnd() so you're not really deserialising, it's more like you are asking it to parse and split the string for you, which it can't do.

JavaScriptSerializer 非常无情，说实话，当我尝试反序列化这样的数组时，我总是会抓狂……最好在服务器端定义一个 DTO 类来处理映射:

 [Serializable]
 public class Titles
 {
    public List<Title> TheTitles { get; set; } 
 }

 [Serializable]
 public class Title
 {
    public string title { get; set; }
 }

现在你的处理程序看起来像这样:

 public void ProcessRequest(HttpContext context)
        {
            try
            {
                context.Response.ContentType = "application/json";
                var data = context.Request;
                var sr = new StreamReader(data.InputStream);
                var stream = sr.ReadToEnd();    
                var javaScriptSerializer = new JavaScriptSerializer();
                var PostedData = javaScriptSerializer.Deserialize<Titles>(stream);    
                foreach (var item in PostedData.TheTitles )
                {
                   //this will write SteveJohnAndrew as expected in the response 
                   //(check the console!)
                   context.Response.Write(item.title);
                }
            }
            catch (Exception msg) { context.Response.Write(msg.Message); }
        }

你的 AJAX 是这样的:

 function upload() 
        {
           //example data
            var Titles = [
                {'title':'Steve'}, {'title':'John'}, {'title':'Andrew'}
            ];    
            var myJSON = JSON.stringify({ TheTitles: Titles });    
            console.log(myJSON);    
            $.ajax({
                async: true,
                contentType: 'application/json; charset=utf-8',
                dataType: 'json',
                type: "POST",
                data: myJSON,
                url: "jsonhandler.ashx",
                success: function (msg) {
                    console.log(msg);
                }     
            });
        }

请注意 DTO 类的定义如何与 JSON 对象属性的定义完全匹配，如果不匹配，则反序列化将不起作用。

希望有帮助。