I'm looking for a elaborated answer and/or explanation (with examples).

I haven't been receiving adequate help from those around me and I feel like nobody explaining what I need in a way I can understand. I almost feel stupid for not getting a solution where everyone else say "that makes sense".

I have been looking at examples...but I just don't get it. I've been applying the code examples and they produce negative results.

Q: The goal is to parse a JSON file with the following format (example link provided). Only the url(s) should be outputted to the console (using a array).

The expected output is

001
002
003
004
005

JSON Example on Hastebin

I was told repeatedly the answer is....

using System.Text.Json;

var json = "{ \"entries\": [ { \"value\": \"hello\", \"anotherValue\": 0 } ]"
var thing = JsonSerializer.Deserialize<Thing>(json);
foreach (var entry in thing.Entries) {
  // do thing with entry.Value and entry.AnotherValue
}
record Thing(OtherThing[] Entries);
record OtherThing(string Value, int AnotherValue);

But I'm clueless. Though this is a proven method that work?

My progress:

    internal class Thing
    {

        public class Download
        {
            public string sha1 { get; set; }
            public string url { get; set; }
        }

        public class Root
        {
            public string _id { get; set; }
            public string name { get; set; }
            public string description { get; set; }
            public string image { get; set; }
            public string url { get; set; }
            public List<Download> download { get; set; }
        }

        public void LoadJson()
        {
            using (StreamReader r = new StreamReader("test2json.json"))
            {
                string json = r.ReadToEnd();
                Root file = JsonConvert.DeserializeObject<Root>(json);
                Trace.WriteLine(json);
            }
        }

In a similar method...I was able to parse a JSON url using...

             //Parse JSON Directory. 
var fileName = (@"C:\Users\Icarus\Desktop\test2json.json");
dynamic json = JsonConvert.DeserializeObject(File.ReadAllText(fileName));
string SearchFor = json["Name"]["Url"];

But this is not a desired result.

Please help me.

I'm using C# and the application is a WPF

CodePudding user response：

Firstly, you need to create model class which represents properties of the json object. For example based on your json file, you can create the following class:

public class RootItem // or whatever name of the root object
{
    [JsonPropertyName("_id")]
    public string Id { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public string Image { get; set; }

    [JsonPropertyName("download")]
    public IEnumerable<Download> Downloads { get; set; }
}

public class Download 
{
    public string Sha1 { get; set; }
    public string Url { get; set; }
}

Secondly, you need to deserialize object (extracting data from a json file). You can use built-in json serializer from System.Text.Json, or you can use Newtonsoft.Json if you are using old frameworks.

In the following example I used default System.Text.Json serializer:

var jsonData = File.ReadAllText("here path of the json file");
var serializerOptions = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
var rootObj = JsonSerializer.Deserialize<RootItem>(jsonData, serializerOptions);

Then get whatever data from deserialized object (in our case it's rootObj) If you want to print all urls then you can do something like:

foreach(var download in rootObj.Downloads)
{
    Console.WriteLine(download.Url)
}