如何在 C# 中清除来自 API 的字符串

Question

I am using C#

in my code, I call API

This API returns a string.

But the problem is when I read the API it comes with backslashes and quotations.

So if the returned value is Black\White's colors

It becomes "\"Black\\\\White's colors\""

or empty string is "\"\""

I wonder if there is a way to parse string the in a right way.

here is my code

        HttpClient client = new HttpClient();
        client.DefaultRequestHeaders.Accept.Add(
        new MediaTypeWithQualityHeaderValue("application/json"));

        string str = client.GetStringAsync(url).Result;

Answer 1

Like this

    HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Accept.Add(
    new MediaTypeWithQualityHeaderValue("application/json"));

    string str = await client.GetStringAsync(url);

    //choose this if using NewtonsoftJson 
    string parsedWithNewtonsoft = JsonConvert.DeserializeObject<string>(str);

    //choose this if using STJ
    string parsedWithSystemTextJson = JsonSerializer.Deserialize<string>(str);

Choose one of the last two lines according to your preferred installed Json parser (manage nuget packages for the project and install either newtonsoft or system.text.json)

Don't use Result; use async proper (which means you have to make your method calls async all the way up the chain). If you strive to turn all your async calls synchronous then your app will spend a lot of tine sitting around doing nothing, waiting for network io to finish, when that time could be put to doing other useful work

Also, HttpClient is not supposed to be created anew every time you want to use it. Either configure your DI with services.AddHttpClient(); passing in options as necessary or if you aren't using DI/not writing a service of your own, you can get some ideas on how to use HttpClientFactory to manufacture HttpClients for you form this question - you may even be able to configure the default request headers as part of the manufacture so you don't need to set them in code

Finally, I should point out that I think there's a chance you're doing a lot more work than you need to if your API you're using publishes a swagger document; if it does you can use a tool like AutoRest (or the "add rest client" feature of visual studio, which uses AR), NSwag, WebApiClientGen etc and tell it "here is the api I want to use" and it'll make everything you need to call the api and return c# objects; you don't need to code any of this low level stuff, pushing data around and parsing responses, yourself