How to Modify JSON object inside JSON array in c#? - c#

This is my Json Array
[
{
"gregdate": "06-03-2019",
"maldate": "22-07-1194",
"gregmonth": "March",
"selected_status": "1"
},
{
"gregdate": "04-05-2019",
"maldate": "21-09-1194",
"gregmonth": "May",
"selected_status": "1"
},
{
"gregdate": "03-06-2019",
"maldate": "20-10-1194",
"gregmonth": "June",
"selected_status": "1"
}
]
In this JSON Array, I want to change 2nd JSON Object "selected_status" value "1" to "0" without changing the position of the JSON Object.

You need to first convert you object array to JArray and then change its second object property from 1 to 0 like
string json = "You json here"; //Load your json
JArray jArray = JArray.Parse(json); //Parse it to JArray
var jObjects = jArray.ToObject<List<JObject>>(); //Get list of objects inside array
foreach (var obj in jObjects) //Loop through on a list
{
if (jObjects.IndexOf(obj) == 1) //Get 2nd object from array
{
foreach (var prop in obj.Properties()) //List 2nd objects properties
{
if (prop.Name == "selected_status") //Get desired property
obj["selected_status"] = 0; //Change its value
}
}
}
JArray outputArray = JArray.FromObject(jObjects); //Output array
Alternative:
As suggested by Brian Rogers you can directly query your JArray to replace its specific property value like,
string json = "You json here"; //Load your json
JArray jArray = JArray.Parse(json); //Parse it to JArray
jArray[1]["selected_status"] = "0"; //Querying your array to get property of 2nd object
string outputJson = jArray.ToString(); //Output json
Output: (from debugger)

This question helped me figure a couple things out - so here is what I came up with. I'm guessing that the json is a sample and what is desired is changing the status for a specific date, rather than just the second element. At least that's what I've been looking for. This is more dynamic and you don't have to worry about the position of the element.
string newJson = "";
if (SwitchStatus(jsonString, "04-05-2019", "0", out newJson))
{
Console.Write(newJson);
}
else
{
Console.WriteLine("Date Not Found");
}
Console.ReadLine();
static bool SwitchStatus(string jsonString, string searchBy, string switchTo, out string output)
{
dynamic jsonObj = JsonConvert.DeserializeObject(jsonString);
JToken status = jsonObj.SelectToken($"$..[?(#.gregdate == '{searchBy}')].selected_status");
if (status != null)
{
status.Replace(switchTo);
output = JsonConvert.SerializeObject(jsonObj, Newtonsoft.Json.Formatting.Indented);
}
else
{
output = jsonString;
}
return status != null;
}

Related

Parse Array inside of an JSON Object with C#

I'm trying to parse an array inside of a json Object but it's not working, here is the code:
public void JsonParserPersonal(string file)
{
string fullname;
string email;
var json = System.IO.File.ReadAllText(file);
var objects = JObject.Parse(json);
var arrays = JArray.FromObject(json);
fullname = (string)objects["NameComponents"]["FullName"];
email = (string)arrays["EmailAddresses"]["ItemValue"];
SearchReplacePersonal(fullname, email);
}
Here is the JSON data:
{
"NameComponents": {
"FullName": "XXX"
},
"EmailAddresses": [
{
"IsPersonal": true,
"IsBusiness": false,
"FieldName": "Email1Address",
"DisplayTitle": "Email",
"ItemValue": "xxx#yyy.com"
}
]
}
All I want is to get the "ItemValue" inside of "EmailAddresses".
When I run this code, this is the error I get:
System.ArgumentException: 'Object serialized to String. JArray instance expected.'
I'm using Visual Studio 2019.
Thanks!
When accessing JArray, you should specify the index
var objects = JObject.Parse(json);
var jarray = objects["EmailAddresses"];
Console.WriteLine((string)objects["NameComponents"]["FullName"]);
Console.WriteLine((string)jarray[0]["ItemValue"]);
Or iterate JArray
foreach(var item in jarray)
{
foreach(JProperty property in item.Children())
{
Console.WriteLine($"{property.Name} - {property.Value}");
}
}

How to change the value of a StringBuilder Parsing through JArray

I have struggled to finish this task, please if anyone can give me a hint I would be so thankful.
My main task is to get data from database using (FOR JSON AUTO) which is working :)
select filed1, field2, field3 from table FOR JSON AUTO;
And then after connecting to Data base I use the StringBuilder() to build a Json Array of objects which is working :)
var jsonResult = new StringBuilder();
if(!r.HasRows)
{
jsonResult.Append("[]");
}
else
{
while(r.Read())
{
jsonResult.Append(r.GetValue(0).ToString());
}
// JArray array = JArray...
}
After that I am trying to change the value of filed1 for each object inside the Json Array
JArray array = JArray.Parse(jsonResult.ToString());
foreach (JObject obj in array.Children<JObject>())
{
foreach (JProperty singleProp in obj.Properties())
{
string name = singleProp.Name;
string value = singleProp.Value.ToString();
if(name.ToString() == "field1")
{
Int64 newID = 1234;
value = newID.ToString();
}
}
}
This is working but My BIG QUESTION is how can I get it changed inside the jsonResult?
You simply have to replace the value that you want to update. Since StringBuilder has a .Replace inbuilt method, you can implement that method.
`JArray arr = JArray.Parse(jsonResult.ToString());
foreach (JObject obj in arr.Children<JObject>())
{
foreach(JProperty singleProp in obj.Properties())
{
string name = singleProp.Name;
string value = singleProp.Value.ToString();
if (name.ToString().Equals("field1")) //good practice
{
Int64 newID = 1234;
jsonResult.Replace(value, newID.ToString());//replacing old value with new value and directly updates jsonResult
}
//not necesssary, explanation is given below
var jsonElement = JsonSerializer.Deserialize<JsonElement>(jsonResult.ToString());
result = JsonSerializer.Serialize(jsonElement, options);
}
}`
And for better formatting, I used JsonSerializer so that your output will look like json object rather than whole string without any lines.
` var options = new JsonSerializerOptions()
{
WriteIndented = true
};
var result = ""
while loop{
jsonResult.Append(r.GetValue(0).ToString());
(Above code)
}
`

Using JArray.Parse(json) on an associative array

I've put together the following code from this answer:
JArray jsonArray = JArray.Parse(json);
foreach(JObject jsonObject in jsonArray.Children<JObject>())
{
foreach(JProperty jProperty in jsonObject.Properties())
{
int id = jProperty.id;
string name = (string)jProperty.Name;
textBox1.AppendText(id.ToString() + " // " + name + Environment.NewLine);
}
}
A sample of the JSON I'm trying to parse is as following:
[{"id":"219","name":"Jimmy"},{"id":"220","name":"Bobby"},{"id":"218","name":"Arthur"}]
The answer I referenced deals with parsing key => value pairs, how can I parse an associative array?
JSON doesn't have "associative arrays". It has arrays and objects.
What you have here is an array of objects. So, JArray.Parse will give you a JArray, and each item in it is itself a JObject:
var array = JArray.Parse(json);
foreach(JObject obj in array)
{
int id = obj.Value<int>("id");
string name = obj.Value<string>("name");
// ...
}

Creating JSON from a CSV file in C#

First of all my apologies because this is going to be a "How to" question rather than a technical question. I have a CSV file as follows-
London,Dubai,4
Dubai,Mumbai,8
Dubai,Dhaka,4
Now my plan is to create a JSON object from that CSV in the following format-
[
{
"From": "London",
"To": "Dubai",
"Duration": 4
},
{
"From": "Dubai",
"To": "Mumbai",
"Duration": 8
},
{
"From": "Dubai",
"To": "Dhaka",
"Duration": 4
},
]
How do I go about and do that? Currently I can load the CSV using OpenFileDialog but no idea what else I should do to get it done? Use Model Classes? JSON.Net? Please advice me and some code samples would be appreciated!
You can add csv records to a List<T> and then serialize it with Newtonsoft.Json to get your required JSON object. See the example below:
class Program
{
static void Main(string[] args)
{
string[] csv = new[] { "London,Dubai,4", "Dubai,Mumbai,8", "Dubai,Dhaka,4" };
List<model> list = new List<model>();
foreach (var item in csv)
{
string[] fields = item.Split(',');
list.Add(new model
{
From = fields[0],
To = fields[1],
Duration = fields[2]
});
}
var json = JsonConvert.SerializeObject(list);
Console.WriteLine(json);
Console.ReadLine();
}
}
public class model
{
public string From { get; set; }
public string To { get; set; }
public string Duration { get; set; }
}
You can use TextFieldParser from the Microsoft.VisualBasic.FileIO namespace and Microsoft.VisualBasic.dll assembly to parse CSV files. Despite the VisualBasic name the class is perfectly usable in c#.
First, add the following extension method:
public static class TextFieldParserExtensions
{
public static IEnumerable<string []> ReadAllFields(this TextFieldParser parser)
{
if (parser == null)
throw new ArgumentNullException();
while (!parser.EndOfData)
yield return parser.ReadFields();
}
}
Now you can use LINQ to transform each CSV line into an anonymous or named type for serialization, like so:
var csv = #"London,Dubai,4
Dubai,Mumbai,8
Dubai,Dhaka,4";
string json;
using (var stream = new StringReader(csv))
using (TextFieldParser parser = new TextFieldParser(stream))
{
parser.SetDelimiters(new string[] { "," });
var query = parser.ReadAllFields()
.Select(a => new { From = a[0], To = a[1], Duration = int.Parse(a[2]) });
json = new JavaScriptSerializer().Serialize(query);
}
Here I am using JavaScriptSerializer but the same code can be used with json.net
json = JsonConvert.SerializeObject(query, Formatting.Indented);
Be sure to evaluate the query before closing the TextFieldParser.
I Believe this should work for all different kinds of .csv files
Comments are in the code
public class Program
{
public static void Main(string[] args)
{
var list = new List<Dictionary<string, string>>();
Console.WriteLine("Put in the path to your .csv file");
var response1 = Console.ReadLine();
Console.WriteLine("Initializing...");
// Read All of the lines in the .csv file
var csvFile = File.ReadAllLines(response1);
// Get The First Row and Make Those You Field Names
var fieldNamesArray = csvFile.First().Split(',');
// Get The Amount Of Columns In The .csv
// Do the -1 so you can use it for the indexer below
var fieldNamesIndex = fieldNamesArray.Count() - 1;
// Skip The First Row And Create An IEnumerable Without The Field Names
var csvValues = csvFile.Skip(1);
// Iterate Through All Of The Records
foreach (var item in csvValues)
{
var newDiction = new Dictionary<string, string>();
for (int i = 0; i < fieldNamesIndex;)
{
foreach (var field in item.Split(','))
{
// Think Of It Like This
// Each Record Is Technically A List Of Dictionary<string, string>
// Because When You Split(',') you have a string[]
// Then you iterate through that string[]
// So there is your value but now you need the field name to show up
// That is where the Index will come into play demonstrated below
// The Index starting at 0 is why I did the -1 on the fieldNamesIndex variable above
// Because technically if you count the fields below its actually 6 elements
//
// 0,1,2,3,4,5 These Are The Field Names
// 0,1,2,3,4,5 These Are The Values
// 0,1,2,3,4,5
//
// So what this is doing is int i is starting at 0 for each record
// As long as i is less than fieldNamesIndex
// Then split the record so you have all of the values
// i is used to find the fieldName in the fieldNamesArray
// Add that to the Dictionary
// Then i is incremented by 1
// Add that Dictionary to the list once all of the values have been added to the dictionary
//
// Add the field name at the specified index and the field value
newDiction.Add(fieldNamesArray.ElementAt(i++), field);
}
list.Add(newDiction);
}
}
Console.WriteLine("Would You Like To Convert To Json Now?");
Console.WriteLine("[y] or [n]");
var response = Console.ReadLine();
if (response == "y")
{
Console.WriteLine("Where Do You Want The New File?");
var response2 = Console.ReadLine();
// Serialize the list into your Json
var json = JsonConvert.SerializeObject(list);
File.Create(response2).Dispose();
File.AppendAllText(response2, json);
Console.WriteLine(json);
Console.ReadLine();
}
else
{
Console.WriteLine("Ok See You Later");
Console.ReadLine();
}
}
}

Parsing a JSON array using Json.Net

I'm working with Json.Net to parse an array. What I'm trying to do is to pull the name/value pairs out of the array and assign them to specific variables while parsing the JObject.
Here's what I've got in the array:
[
{
"General": "At this time we do not have any frequent support requests."
},
{
"Support": "For support inquires, please see our support page."
}
]
And here's what I've got in the C#:
WebRequest objRequest = HttpWebRequest.Create(dest);
WebResponse objResponse = objRequest.GetResponse();
using (StreamReader reader = new StreamReader(objResponse.GetResponseStream()))
{
string json = reader.ReadToEnd();
JArray a = JArray.Parse(json);
//Here's where I'm stumped
}
I'm fairly new to JSON and Json.Net, so it might be a basic solution for someone else. I basically just need to assign the name/value pairs in a foreach loop so that I can output the data on the front-end. Has anyone done this before?
You can get at the data values like this:
string json = #"
[
{ ""General"" : ""At this time we do not have any frequent support requests."" },
{ ""Support"" : ""For support inquires, please see our support page."" }
]";
JArray a = JArray.Parse(json);
foreach (JObject o in a.Children<JObject>())
{
foreach (JProperty p in o.Properties())
{
string name = p.Name;
string value = (string)p.Value;
Console.WriteLine(name + " -- " + value);
}
}
Fiddle: https://dotnetfiddle.net/uox4Vt
Use Manatee.Json
https://github.com/gregsdennis/Manatee.Json/wiki/Usage
And you can convert the entire object to a string, filename.json is expected to be located in documents folder.
var text = File.ReadAllText("filename.json");
var json = JsonValue.Parse(text);
while (JsonValue.Null != null)
{
Console.WriteLine(json.ToString());
}
Console.ReadLine();
I know this is about Json.NET but times are a-changing so if anybody stumbles here while using .NET Core/5+ System.Text.Json please don't despair because
Try the new System.Text.Json APIs from .NET Blog show an example of this.
[
{
"date": "2013-01-07T00:00:00Z",
"temp": 23,
},
{
"date": "2013-01-08T00:00:00Z",
"temp": 28,
},
{
"date": "2013-01-14T00:00:00Z",
"temp": 8,
},
]
...
using (JsonDocument document = JsonDocument.Parse(json, options))
{
int sumOfAllTemperatures = 0;
int count = 0;
foreach (JsonElement element in document.RootElement.EnumerateArray())
{
DateTimeOffset date = element.GetProperty("date").GetDateTimeOffset();
(...)

Categories

Resources