How to Read a JSON File in C#

This tutorial will discuss methods to read a JSON file in C#.

Read a JSON File With the JsonConvert Class in C#

The JsonConvert class can be used to read JSON data into objects and variables and write objects and variables in JSON format in C#. The JsonConvert class is present in the Json.net framework, which does not come pre-installed. The command to install Json.net is given below.

Install-Package Newtonsoft.Json

In this article, we will use the following JSON data.

{
    "key1": "value1",
    "key2": "value2",
    "key3": "value3"
}

In order to read data from this file, we first have to create a model class that contains all the attributes that we want to read from the file.

file.json:

class datamodel {
  public string key1 { get; set; }
  public string key2 { get; set; }
  public string key3 { get; set; }
}

Now we have a model class that will store all the data from the JSON file into class objects. We can get data from a file with the JsonConvert.DeserializeObject() function in C#. The JsonConvert.DeserializeObject() function takes the JSON data in the form of a string variable and converts it into the specified data-model class object. The following code example shows us how we can get the data from a JSON file in class objects with the JsonConvert.DeserializeObject() function in C#.

StreamReader r = new StreamReader("file.json");
string jsonString = r.ReadToEnd();
datamodel m = JsonConvert.DeserializeObject<datamodel>(jsonString);

We initialized a StreamReader - r to read the file containing the JSON data file.json. We then initialized the jsonString, which is all the data inside the file.json file. We created an instance of the datamodel class m to store the value returned by the JsonConvert.DeserializeObject<datamodel>(jsonString) function. This the easiest method to read data from and write data to a JSON file in C#.