In this post, we are going to learn about serializing objects to XML in C#.<\/p>\n
So, what is XML Serialization?\u00a0 It is the transformation of the public fields and property values of an object (without type information) into an XML stream.<\/strong><\/p>\n After the main definition, we can continue to see how to serialize objects to XML with several examples.\u00a0<\/p>\n For serializing objects to XML in C#, we can use the The Next, let’s create a new object of type Here, we create an The resulting XML file consists of an XML Root Element and all the information of the Note that the tags of the XML elements have exactly the same name as the properties of the There are some important details about XML serialization in C# that we should be aware of. First of all, every class that we want to serialize should define the default (parameterless) constructor.<\/strong> In our case, we have not defined any constructors. Therefore, the parameterless constructor is included by default.<\/p>\n Moreover, only the public members of a class will be serialized; private members will be omitted from the XML document<\/strong>.<\/p>\n The properties must have a public getter method<\/strong>. If they also have a setter method, this must be public too.<\/p>\n We can also serialize classes that contain objects from other classes.\u00a0<\/p>\n Let’s introduce a new class that contains information about the patient’s home address:<\/p>\n Next, we are going to modify the To serialize the The resulting XML is going to have an additional element with the patient’s address details:<\/p>\n In order to serialize an array of objects, we have to instruct The resulting XML now contains a Root Element with the name The Each We can serialize a Our XML file will now have an array of elements with the corresponding measurements:<\/p>\n We can influence the serialization of an object with the use of C# Attributes. In this way, we can serialize an object property as an XML attribute (instead of an XML element). Moreover, we can select a different name for an element tag. We can also prevent a property from appearing in the resulting XML.<\/p>\n So, let’s start with the First of all, we can change the name of the Root Element from Next, we choose to serialize the The How to Serialize a Simple Object to XML in C#<\/h2>\n
XmlSerializer<\/code> class from the System.Xml.Serialization<\/code> namespace. We are going to start with the serialization of a simple C# class:<\/p>\npublic class Patient\r\n{\r\n public int ID { get; set; }\r\n public string FirstName { get; set; }\r\n public string LastName { get; set; }\r\n public DateTime Birthday { get; set; }\r\n public int RoomNo { get; set; }\r\n}<\/pre>\nPatient<\/code> class contains the necessary information for a hospital patient.<\/p>\nPatient<\/code>. We are going to serialize it into an XML file using the XmlSerializer<\/code> class:<\/p>\nvar patient = new Patient()\r\n{\r\n ID = 232323,\r\n FirstName = \"John\",\r\n LastName = \"Doe\",\r\n Birthday = new DateTime(1990, 12, 30),\r\n RoomNo = 310\r\n};\r\n\r\nvar serializer = new XmlSerializer(typeof(Patient));\r\nusing (var writer = new StreamWriter(\"patients.xml\"))\r\n{\r\n serializer.Serialize(writer, patient);\r\n}\r\n<\/pre>\nXMLSerializer<\/code> object that will serialize objects of type Patient<\/code>. The Serialize()<\/code> method transforms the object into XML. It also uses a StreamWriter<\/code> object to write the XML into a file.<\/p>\nPatient<\/code> object:<\/p>\n<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<Patient xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\" xmlns:xsd=\"http:\/\/www.w3.org\/2001\/XMLSchema\">\r\n <ID>232323<\/ID>\r\n <FirstName>John<\/FirstName>\r\n <LastName>Doe<\/LastName>\r\n <Birthday>1990-12-30T00:00:00<\/Birthday>\r\n <RoomNo>310<\/RoomNo>\r\n<\/Patient><\/pre>\n
Patient<\/code> object. We can change their names with the use of C# Attributes<\/strong>, as we will see later on.<\/p>\nThings to Note About Serialization in C#<\/h3>\n
Serializing Classes with Nested Classes to XML<\/h2>\n
public class Address\r\n{\r\n public string Street { get; set; }\r\n public string Zip { get; set; }\r\n public string City { get; set; }\r\n public string Country { get; set; }\r\n}<\/pre>\nPatient<\/code> with a reference to Address<\/code>:<\/p>\npublic class Patient\r\n{\r\n public int ID { get; set; }\r\n public string FirstName { get; set; }\r\n public string LastName { get; set; }\r\n public DateTime Birthday { get; set; }\r\n public int RoomNo { get; set; }\r\n public Address HomeAddress { get; set; }\r\n}<\/pre>\npatient<\/code> object, we are going to use the XmlSerializer<\/code> class:<\/p>\nvar patient = new Patient()\r\n{\r\n ID = 232323,\r\n FirstName = \"John\",\r\n LastName = \"Doe\",\r\n Birthday = new DateTime(1990, 12, 30),\r\n RoomNo = 310,\r\n HomeAddress = new Address()\r\n {\r\n Street = \"12 Main str.\",\r\n Zip = \"23322\",\r\n City = \"Boston\",\r\n Country = \"USA\",\r\n }\r\n};\r\n\r\nvar serializer = new XmlSerializer(typeof(Patient));\r\nusing (var writer = new StreamWriter(\"patients.xml\"))\r\n{\r\n serializer.Serialize(writer, patient);\r\n}\r\n<\/pre>\n<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<Patient xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\" xmlns:xsd=\"http:\/\/www.w3.org\/2001\/XMLSchema\">\r\n <ID>232323<\/ID>\r\n <FirstName>John<\/FirstName>\r\n <LastName>Doe<\/LastName>\r\n <Birthday>1990-12-30T00:00:00<\/Birthday>\r\n <RoomNo>310<\/RoomNo>\r\n <HomeAddress>\r\n <Street>12 Main str.<\/Street>\r\n <Zip>23322<\/Zip>\r\n <City>Boston<\/City>\r\n <Country>USA<\/Country>\r\n <\/HomeAddress>\r\n<\/Patient><\/pre>\n
An Array of Objects Serialization<\/h2>\n
XmlSerializer<\/code> to expect objects of type Patient[]<\/code>:<\/p>\nvar arr = new Patient[]\r\n{\r\n new Patient()\r\n {\r\n ...\r\n },\r\n new Patient()\r\n {\r\n \u00a0... \r\n }\r\n};\r\n\r\nvar arrSerializer = new XmlSerializer(typeof(Patient[]));\r\nusing (var writer = new StreamWriter(\"patients.xml\"))\r\n{\r\n arrSerializer.Serialize(writer, arr);\r\n}\r\n<\/pre>\nArrayOfPatient<\/code>:<\/p>\n<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<ArrayOfPatient xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\" xmlns:xsd=\"http:\/\/www.w3.org\/2001\/XMLSchema\">\r\n <Patient>\r\n ...\r\n <\/Patient>\r\n <Patient>\r\n ...\r\n <\/Patient>\r\n<\/ArrayOfPatient><\/pre>\n
Serializing Classes with Lists of Objects to XML<\/h2>\n
XmlSerializer<\/code> class can also serialize classes that contain lists (or arrays) of objects:<\/p>\npublic class Patient\r\n{\r\n public int ID { get; set; }\r\n public string FirstName { get; set; }\r\n public string LastName { get; set; }\r\n public DateTime Birthday { get; set; }\r\n public int RoomNo { get; set; }\r\n public Address HomeAddress { get; set; }\r\n public List<Measurement> Measurements {get; set;} \r\n}<\/pre>\nMeasurement<\/code> stores temperature readings for the patient:<\/p>\npublic class Measurement\r\n{\r\n public DateTime TimeTaken { get; set; }\r\n public decimal Temp { get; set; }\r\n}<\/pre>\nPatient<\/code> object in the same way as before:<\/p>\nvar patient = new Patient()\r\n{\r\n ID = 232323,\r\n ...\r\n HomeAddress = new Address()\r\n {\r\n Street = \"12 Main str.\",\r\n ...\r\n },\r\n Measurements = new List<Measurement>()\r\n {\r\n new Measurement() { TimeTaken = new DateTime(2022, 1, 1, 17, 50, 0), Temp = 38.4M },\r\n new Measurement() { TimeTaken = new DateTime(2022, 1, 1, 22, 00, 0), Temp = 39.1M },\r\n new Measurement() { TimeTaken = new DateTime(2022, 1, 2, 6, 30, 0), Temp = 37.3M }\r\n }\r\n};\r\n\r\nvar serializer = new XmlSerializer(typeof(Patient));\r\nusing (var writer = new StreamWriter(\"patients.xml\"))\r\n{\r\n serializer.Serialize(writer, patient);\r\n}\r\n<\/pre>\n<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<Patient xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\" xmlns:xsd=\"http:\/\/www.w3.org\/2001\/XMLSchema\">\r\n ....\r\n <Measurements>\r\n <Measurement>\r\n <TimeTaken>2022-01-01T17:50:00<\/TimeTaken>\r\n <Temp>38.4<\/Temp>\r\n <\/Measurement>\r\n <Measurement>\r\n <TimeTaken>2022-01-01T22:00:00<\/TimeTaken>\r\n <Temp>39.1<\/Temp>\r\n <\/Measurement>\r\n <Measurement>\r\n <TimeTaken>2022-01-02T06:30:00<\/TimeTaken>\r\n <Temp>37.3<\/Temp>\r\n <\/Measurement>\r\n <\/Measurements>\r\n<\/Patient><\/pre>\n
<\/a>Controlling XML Serialization in C#<\/h2>\n
Patient<\/code> class modification by adding the required attributes:<\/p>\n[XmlRoot(\"PatientInfo\")]\r\npublic class Patient\r\n{\r\n [XmlAttribute (\"PatientID\")]\r\n public int ID { get; set; }\r\n public string FirstName { get; set; }\r\n public string LastName { get; set; }\r\n [XmlIgnore]\r\n public DateTime Birthday { get; set; }\r\n [XmlElement(\"RoomNumber\")]\r\n public int RoomNo { get; set; }\r\n public Address HomeAddress { get; set; }\r\n [XmlArray(\"TemperatureReadings\")]\r\n [XmlArrayItem(\"TemperatureReading\")]\r\n public List<Measurement> Measurements {get; set;} \r\n}<\/pre>\nPatient<\/code> to PatientInfo<\/code>, using of XmlRoot<\/code> annotation.<\/p>\nID<\/code> property as an XmlAttribute<\/code>, under the name PatientID<\/code>.<\/p>\nXmlIgnore<\/code> annotation prevents a property from appearing in the XML. Here, we use it to omit the patient’s birthday from the resulting file.<\/p>\n