Dhananjay Kumar

In this tutorial step by step we will learn to save and Retrieve JSON data in Local folder of Windows Store App.

Follow following steps to save and retrieve JSON data in local storage.

Step 1

Right click on project and add Nuget package and add package of Json.NET.

Step 2

Let us assume that we need to store Student information in local storage. For that I have created a Student class.

public class Student
    {
        public string Name { get; set; }
        public string City { get; set; }
        public string Grade { get; set; }
    }

Step 3

Before saving data we need to serialize the class into JSON. We will serliaze that using JSON.net library. After serializing object into JSON we will save data in local folder of windows store application.

            string jsonContents = JsonConvert.SerializeObject(s);           
           StorageFolder localFolder = ApplicationData.Current.LocalFolder;
           StorageFile textFile = await localFolder.CreateFileAsync("a.txt",CreationCollisionOption.ReplaceExisting);
            using (IRandomAccessStream textStream = await textFile.OpenAsync(FileAccessMode.ReadWrite))
            {
        
                using (DataWriter textWriter = new DataWriter(textStream))
                {
                    textWriter.WriteString(jsonContents);
                    await textWriter.StoreAsync();
                }
            }

        }

S is object of class Student. We are reading student properties from various textboxes.

            Student s = new Student
            {
                Name =txtName.Text,
                City = txtCity.Text,
                Grade =txtGrade.Text
            };

In above code snippet,

• We are saving file in application local folder
• Data is saved in file a.txt
• Opening file in asynchronous way for read write operation using IRandomAccessStream
• Using DataWriter to write data in file

In these four steps data can be saved in local folder of Windows Store Application.

Step 4

To read JSON data back we need to first read data from local storage and then deserliaze that to object from JSON. Reading data is very simple.

• Open local folder
• Load file asynchronously
• Open file asynchronously to read the streams
• Using DataReader reading stream
• Convert JSON to object

StorageFolder localFolder = ApplicationData.Current.LocalFolder;
           StorageFile textFile = await localFolder.GetFileAsync("a.txt");
                using (IRandomAccessStream textStream = await textFile.OpenReadAsync())
                {
                       
                    using (DataReader textReader = new DataReader(textStream))
                    {                                            
                        uint textLength = (uint)textStream.Size;
                        await textReader.LoadAsync(textLength);
                        string jsonContents = textReader.ReadString(textLength);                      
                        Student s = JsonConvert.DeserializeObject<Student>(jsonContents);
                        txtName1.Text = s.Name;
                        txtCity1.Text = s.City;
                        txtGrade1.Text = s.Grade;
                       
                    }
                }

In above code snippet,

• We are opening local folder
• Opening file asynchronously
• Reading stream in IRandonAccessStream
• Reading data using DataReader
• DeSeralizing JSON to object using JsonConver

By following above steps you can save and retrieve data in local folder of Windows Store application. I hope you find this article useful.