c# - 从 Asp.Net WebApi 返回字符串后的 JsonConvert DeserializeObject 异常

Question

我正在使用 WebApi 返回 Json 字符串，'返回的字符串在下面的代码中被注释'

private async void setDataContext()
    {
        var str = (await HttpVerbs.HttpGet("commandelist/1"));
        //"[{\"Num\":\"10\",\"NomRestau\":\"Woodpecker\",\"Date\":\"11/23/2013 6:02:00 PM\",\"Total\":\"200\",\"Etat\":\"False\"},{\"Num\":\"9\",\"NomRestau\":\"Woodpecker\",\"Date\":\"11/23/2013 6:02:00 PM\",\"Total\":\"200\",\"Etat\":\"False\"},{\"Num\":\"8\",\"NomRestau\":\"Woodpecker\",\"Date\":\"11/23/2013 6:02:00 PM\",\"Total\":\"200\",\"Etat\":\"False\"}]";

        cmdList = (ObservableCollection<CommandeList>)JsonConvert.DeserializeObject(str, typeof(ObservableCollection<CommandeList>));
        Listu.DataContext = cmdList;
    }

这里是 HttpVerbs 类

public class HttpVerbs
{

    public static async Task<string> HttpGet(string url)
    {
        var httpClient = new HttpClient();

        return (await httpClient.GetStringAsync("http://{myWebSite}/api/" + url));
    }
}

• 如果我直接将注释的 Json 字符串分配给“str”(变量)，一切正常! 但是，如果我尝试从我的 webApi 获取它(就像我在这段代码中所做的那样)，则会抛出异常

{Newtonsoft.Json.JsonSerializationException: Error converting value "[{"Num":"10","NomRestau":"Woodpecker","Date":"11/23/2013 6:02:00 PM","Total":"200","Etat":"False"},{"Num":"9","NomRestau":"Woodpecker","Date":"11/23/2013 6:02:00 PM","Total":"200","Etat":"False"},{"Num":"8","NomRestau":"Woodpecker","Date":"11/23/2013 6:02:00 PM","Total":"200","Etat":"False"}]" to type 'System.Collections.ObjectModel.ObservableCollection`1[RestO.Models.CommandeList]'. Path '', line 1, position 355.

备注:我的字符串包含 355 个字符。

我用这个作为模型“”

public class CommandeList
{
    public string Num { get; set; }
    public string NomRestau { get; set; }
    public string Date { get; set; }
    public string Total { get; set; }
    public string Etat { get; set; }
}

Answer 1

只是猜测，没有看到你如何从 WebApi 返回这个字符串。如果您的 Controller 操作方法返回字符串类型，这将不起作用。

返回 Json 字符串的正确方法显示在这个答案中: Return a JSON string explicitly from Asp.net WEBAPI?

需要打包到HttpResponseMessage中。