CODEWITHSUNDEEP
c#file
questioner9928
questioner9928

Reputation: 21

Cannot read JSON nested file

I have to read a JSON file that is stored locally in my machine but it gives me empty data when I try to access a specific item.

Here's my JSON file structure:

{
    "food": [{
            "id": "8a7f65c47cdb33f4017d08fff1fe3cee",
            "rules": [

            ],

            "fruit": "Apple",
            "size": "Large",
            "color": "Red"
        }
    ]
}

Here's what I have tried:

//test.json is the name of my file
string fileName = "test.json";
string jsonString = File.ReadAllText(fileName);
Item item = JsonConvert.DeserializeObject<Item>(jsonString);

//here I want to print out the fruit "Apple" but it gives me null;
Console.WriteLine($"Fruit:" + item.fruit);

Item class:

public class Item
{
    public string fruit;
    public string size;
    public string color;
    public string id;
    public string rules;
}

PS: If I noticed that this code will work only if my data structure is without the "food" block, and it think that is the problem here. Any ideas on how can I fix this?

Upvotes: 1

Views: 695

Answers (3)

Tim Lind
Tim Lind

Reputation: 160

Your Item class does not match the JSON datastructure. You are missing that food is a List of Objects in the JSON structure. Your Item class only represents the Object right now. It also misses that rules is a List too.

Try:

public class Food
{
    public string id { get; set; }
    public List<object> rules { get; set; }
    public string fruit { get; set; }
    public string size { get; set; }
    public string color { get; set; }
}

public class Root
{
    public List<Food> food { get; set; }
}

You would also need to change Item to Root like this:

Root item = JsonConvert.DeserializeObject<Root>(jsonString);

Then you should find fruit like this:

Console.WriteLine($"Fruit:" + item.food[0].fruit);

Upvotes: 0

Aviv Halevy
Aviv Halevy

Reputation: 171

The item class doesnt match to your json, here is my suggest for this case:

    public class Food
{
    public string id { get; set; }
    public List<object> rules { get; set; }
    public string fruit { get; set; }
    public string size { get; set; }
    public string color { get; set; }
}

public class FoodList
{
    public List<Food> food { get; set; }
}

I created a button to make this convert

        private void btnConvert_Click(object sender, EventArgs e)
    {
        
        string fileName = "YOUR_PATH\\test.json";
        string jsonString = File.ReadAllText(fileName);
        FoodList l = JsonConvert.DeserializeObject<FoodList>(jsonString);
  
        tbResult.Text = $"Fruit:" + l.food[0].fruit;

    }

Added gif: DeserializeObject

Upvotes: 1

Zalhera
Zalhera

Reputation: 639

The item class does not represent the correct structure for your JSON data. You have a root object which contains a property that is a list of another object.

To correctly deserialize your JSON data your class should look something like this:

public class Food
{
    public string id { get; set; }
    public List<object> rules { get; set; }
    public string fruit { get; set; }
    public string size { get; set; }
    public string color { get; set; }
}

public class Root
{
    public List<Food> food { get; set; }
}

You can use this to quickly generate fitting models in C# from JSON data.

Upvotes: 1

Related Questions