C# Discussion Boards - CodeProject

Sandeep Vemulapalli27-Dec-17 11:10

27-Dec-17 11:10

Hey Guys,

Hope you guys are doing great! I have one question kind of stuck there. In the JSON File, I would like to extract the data from the node. Say like I wanted to extract the book node or value which is within goods node. Here is my JSON file.

{"store": [
{
    "name": "Sunshine Department Store",
    "address": "Wangfujing Street",
    "goods": {
        "book": [
            {
                "category": "Reference",
                "title": "Sayings of the Century",
                "author": "Nigel Rees",
                "price": 8.88
            },
            {
                "category": "Fiction",
                "title": "Sword of Honour",
                "author": "Evelyn Waugh",
                "price": 12.66
            }
        ],
        "bicycle": {
            "type": "GIANT OCR2600",
            "color": "White",
            "price": 276
        }
    }
}
]
}

Here is my code

private string ParseBookNode(JObject bookJSONFile)
        {
            JArray bookJson = null;
            string bookFarmNode = null;
            if (bookJSONFile != null && bookJSONFile["store"] != null)
            {
                bookJson = (JArray)bookJSONFile["store"];
                bookFarmNode = bookJson[0].ToString();

                if (bookJSONFile["book"] != null)
                {
                    bookJson = (JArray)bookJSONFile["book"];
                    bookFarmNode = bookJson[0].ToString();
                }
            }
            else
            {
                throw new Exception("Book node not found.");
            }
            return bookFarmNode;
        }

How I can able to extract data along this lines??

if (bookJSONFile["book"] != null)
                {
                    bookJson = (JArray)bookJSONFile["book"];
                    bookFarmNode = bookJson[0].ToString();
                }

Re: Extracting a node from Json File in C#

Nathan Minier28-Dec-17 1:52

Nathan Minier

28-Dec-17 1:52

You will find that life will be much, much easier if you write container classes for these JSON objects and deserialize directly into instances of those objects. It'll also help you handle these items as strongly-typed objects in your code. I can tell you've done a bit of XML handling in the past, and it's just a different way of handling it.

public abstract class Product
{
   public decimal Price { get; set; }
}

public class Book : Product
{
   public string Category { get; set; } // This could be a relationship or enum
   public string Title { get; set; }
   public string Author { get; set; }
}

public class Bicycle : Product
{
   public string Type { get; set; } //this would be a good spot for an entity relationship
   public string Color { get; set; } // This could be a relationship or enum

}

public class Store
{
   public string Name { get; set; } 
   public string Address { get; set; }
   public Dictionary<string,List<Product>> Goods { get; set; }

   public Store()
   {
      Goods = new Dictionary<string,List<Product>>();
   }
}

There are a couple of ways to handle the "goods" collection, but this is the easiest and should work with JSON.Net out of the box. How you obtain your object can vary a little, but parsing it directly from the original stream is preferable just for efficiency:

public Store GetStoreInventory(string fileName)
{
   using(var jsonFile = new FileStream(fileName))
   {
      using(var reader = new StreamReader(jsonFile))
      {
         return JsonConvert.DeserializeObject<Store>(reader.ReadToEnd());
      }
   }
}

From here you can handle the data just like you would any normal .NET CLR type, i.e.

var store = GetStoreInventory(FILEPATH);
var firstBook = store.Goods["book"].FirstOrDefault();

The only "gotcha" is that the JSON.NET deserialize does not play nicely with interfaces, so use abstract classes instead (hence Product rather than IProduct).

"There are three kinds of lies: lies, damned lies and statistics."
- Benjamin Disraeli

C # + Regex help (for a newbie)

Damian Bz27-Dec-17 4:16

Damian Bz

27-Dec-17 4:16

Hi All,
I have just started to self learn C#, and have written my first basic application.

It is pretty simple,it has 8 text boxes that accept numerical values, which it then does some calculations on and displays 3 textbox outputs.

I worked out the calculations using Excel then translated that into C# and it all works ! as long as no one puts the wrong numbers in !

What I am trying to achieve is to validate four types of inputs:

One set of text boxes can accept whole numbers and no letters from 1 to 1000
One set of text boxes can accept whole numbers and no letters from 1 to 100

On these two types of textboxes, I have this code:

private void totalsize_TextChanged(object sender, EventArgs e)
{
    if (System.Text.RegularExpressions.Regex.IsMatch(totalsize.Text, "[^0-9]"))
    {
        MessageBox.Show("Please enter only full numbers i.e. 70  NOT  65.5");
        totalsize.Text = totalsize.Text.Remove(totalsize.Text.Length - 1);
        totalsize.Focus();
    }
}

From what I understand the regex is basically checking that the first character is not non numerical, so it sort of does one part of what I needed it to do.

I then have another input that I want to be able to validate: numbers only again, but only allow a single number with a single decimal point i.e. 7.2 3.6 but not 7.22222 or 70 so anything from 1 to 9 including a single decimal point.

private void nicstrength_TextChanged(object sender, EventArgs e)
{
        if (System.Text.RegularExpressions.Regex.IsMatch(nicstrength.Text, "insert jibberish here"))
        {
            MessageBox.Show("Please enter only numbers.");
            nicstrength.Text = nicstrength.Text.Remove(nicstrength.Text.Length - 1);
            nicstrength.Focus();
        }

    }

The last input I want to validate will be again numbers only but from 0.n to 2.n , so 0.6 or .6 - 1.2 or 2 (2 or above will probably not ever get entered)

private void finalnicstrength_TextChanged(object sender, EventArgs e)
{
    if (System.Text.RegularExpressions.Regex.IsMatch(finalnicstrength.Text, @"^[1-9]\d*(\.\d+)?$"))
    {
        MessageBox.Show("Please enter only numbers.");
        finalnicstrength.Text = finalnicstrength.Text.Remove(finalnicstrength.Text.Length - 1);
        finalnicstrength.Focus();
    }
}

I have tried zillions of combinations found on the net, plus I've used a couple of regex generators (frustratingly, some say a regex works and some say it doesn't - but none work when I put them into my code !)
I've learnt that I either need to put an @ in front of it, or use double \\ or whatever for C# to know what it is, but i'm just really struggling with this.
I am dyslexic (not looking for sympathy) so looking at regex makes my head explode !

Please can someone help me with the last two types at the very least, I know the top two are not 100% correct, but they at least stop letters and decimal points being entered.

Many thanks for reading, and even more for helping me ! Smile | :)

Damian