Question

C#

Create a console application named that creates a list of shapes, uses serialization to save it to the filesystem using XML, and then deserializes it back:

// create a list of Shapes to serialize
var listOfShapes = new List<Shape>
{
new Circle { Colour = "Red", Radius = 2.5 },
new Rectangle { Colour = "Blue", Height = 20.0, Width = 10.0 },
new Circle { Colour = "Green", Radius = 8 },
new Circle { Colour = "Purple", Radius = 12.3 },
new Rectangle { Colour = "Blue", Height = 45.0, Width = 18.0 }
};

Shapes should have a read-only property named Area so that when you deserialize, you can output a list of shapes, including their areas, as shown here:

List<Shape> loadedShapesXml = serializerXml.Deserialize(fileXml)
as List<Shape>;
foreach (Shape item in loadedShapesXml) {
WriteLine($"{item.GetType().Name} is {item.Colour} and has an
area of {item.Area}");
}

This is what your output should look like when you run the application:

Loading shapes from XML:
Circle is Red and has an area of 19.6349540849362
Rectangle is Blue and has an area of 200
Circle is Green and has an area of 201.061929829747
Circle is Purple and has an area of 475.2915525616
Rectangle is Blue and has an area of 810

Answer 1

Short Summary:

• First, Implement Shape abstract class. Then extend it to Rectangle and Circle.
• Use serialize attribute as required

Source Code:

Shape.cs File:

using System;

using System.Xml.Serialization;

namespace SerializeDemo

{

    [XmlInclude(typeof(Circle))]

    [XmlInclude(typeof(Rectangle))]

    [Serializable]

    public abstract class Shape

    {

        public string Colour { get; set; }

        public abstract double Area { get; }

    }

}

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Circle.cs File:

using System;

namespace SerializeDemo

{

    [Serializable]

    public class Circle:Shape

    {

        public double Radius { get; set; }

        // circle Area = pi * radius^2

        public override double Area { get { return 3.14 * Radius * Radius; } }

    }

}

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Rectangle.cs File:

using System;

namespace SerializeDemo

{

    [Serializable]

    public class Rectangle:Shape

    {

        public double Height { get; set; }

        public double Width { get; set; }

        // Rectangle Area = Height * Width

        public override double Area { get { return Height * Width; } }

    }

}

***************************************************

DemoProgram

using System;

using System.Collections.Generic;

using System.Xml.Serialization;

using System.IO;

namespace SerializeDemo

{

    class Program

    {

        static void Main(string[] args)

        {

            string filePath = "Shapes.xml";

           

            // create a list of Shapes to serialize

            var listOfShapes = new List<Shape>

                {

                new Circle { Colour = "Red", Radius = 2.5 },

                new Rectangle { Colour = "Blue", Height = 20.0, Width = 10.0 },

                new Circle { Colour = "Green", Radius = 8 },

                new Circle { Colour = "Purple", Radius = 12.3 },

                new Rectangle { Colour = "Blue", Height = 45.0, Width = 18.0 }

                };

         

            // Serialize the object

            XmlSerializer serializerXml = new XmlSerializer(typeof(List<Shape>));

            System.IO.FileStream fileXmlSerialize = System.IO.File.Create(filePath);

            serializerXml.Serialize(fileXmlSerialize, listOfShapes);

            fileXmlSerialize.Close();

            //Deserialize the object

            using (StreamReader fileXml = new StreamReader(filePath))

            {

                List<Shape> loadedShapesXml = serializerXml.Deserialize(fileXml) as List<Shape>;

                foreach (Shape item in loadedShapesXml)

                {

                    Console.WriteLine($"{item.GetType().Name} is {item.Colour} and has an area of { item.Area}");

                }

            }

            Console.ReadLine();

        }

    }

}

Sample Run:

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