.NET Development Foundation/Serialization

Serialization and Input/Output Serialization and Input/Output Exam objective: Implementing serialization and input/output functionality in a .NET Framework application Topics Serialization serialization Wikipedia's definition for serialization is : "in the context of data storage and transmission, serialization is the process of saving an object onto a storage medium (such as a file, or a memory buffer) or to transmit it across a network connection link in binary form". The problem that is addressed here is that an object is created by a running process and is thus bound to the lifetime of that process instance. If for whatever reason, and there can be many, you want to "transport" the object in the context of another process instance you've got a problem, that you solve by "saving" the state of you object in the original process and "restoring" it in the destination process. This "saving" part is called serialization and the "restoring" part is called deserialization. Serializable attribute An object is serializable if its class name is prefixed with the [Serializable] attribute. Object Serialization One can use the BinaryFormatter class to serialize an object. To serialize, use the BinaryFormatter's Serialize() method which takes a stream and a serializable object as parameters. To deserialize, use the BinaryFormatter's Deserialize() method which takes a stream as a parameter and returns a object that can be cast back to the original object type. Remember to close streams after you use them by calling the stream's Close() method. XML Serialization One can use the XmlSerializer class to serialize an object. To serialize, use the XmlSerializer's Serialize() method which takes a stream and a serializable object as parameters. To deserialize, use the XmlSerializer's Deserialize() method which takes a stream as a parameter and returns a object that can be cast back to the original object type. Remember to close streams after you use them by calling the stream's Close() method. For an overview of XML and SOAP serialization see MSDN Custom Serialization The ISerializable interface allows an object to control its own serialization and deserialization. Readers Writers Formatters A formatter is used to serialize objects into streams. Streams File IO Managing Byte Streams Compression Isolated storage For a general discussion on IsolatedStorage tasks see MSDN Classes, Interfaces, and tools Serialize and deserialize Exam objective: Serialize or deserialize an object or an object graph by using runtime serialization techniques. (Refer System.Runtime.Serialization namespace) Serialization interfaces IDeserializationCallback interface - MSDN IFormatter interface and IFormatterConverter interface IFormatter interface - MSDN IFormatterConverter interface - MSDN ISerializable interface - MSDN Serialization attributes Gods Son Hampton euguen Brent Benard pentocostal Baptist Barber For some serialization attributes exemple see MSDN OnDeserializedAttribute class and OnDeserializingAttribute class OnDeserializedAttribute class - MSDN OnDeserializingAttribute class - MSDN OnSerializedAttribute class and OnSerializingAttribute class OnSerializedAttribute class - MSDN OnSerializingAttribute class - MSDN OptionalFieldAttribute class - MSDN SerializationEntry structure and SerializationInfo class SerializationEntry structure - MSDN SerializationInfo class - MSDN ObjectManager class ObjectManager class - MSDN Formatter class, FormatterConverter class, and FormatterServices class Formatter class - MSDN FormatterConverter class - MSDN FormatterServices class - MSDN StreamingContext structure StreamingContext structure - MSDN XML Serialization Exam objective: Control the serialization of an object into XML format by using the System.Xml.Serialization namespace. XmlSerializer class - MSDN Exam objective: Serialize and deserialize objects into XML format by using the XmlSerializer class Control serialization by using serialization attributes - MSDN For a list of attributes for controlling serialization see MSDN Implement XML Serialization interfaces to provide custom formatting for XML serialization - MSDN Delegates and event handlers are provided by the System.Xml.Serialization namespace - MSDN Custom serialization Exam objective: Implement custom serialization formatting by using the Serialization Formatter classes. SoapFormatter class - MSDN (Refer System.Runtime.Serialization.Formatters.Soap namespace) BinaryFormatter class - MSDN (Refer System.Runtime.Serialization.Formatters.Binary namespace File system classes Exam objective: Access files and folders by using the File System classes. (Refer System.IO namespace) File class and FileInfo class For common IO tasks see MSDN File class - MSDN FileInfo class - MSDN Directory class and DirectoryInfo class Directory class - MSDN DirectoryInfo class - MSDN DriveInfo class and DriveType enumeration DriveInfo class - MSDN DriveType enumeration - MSDN FileSystemInfo class and FileSystemWatcher class FileSystemInfo class FileSystemWatcher class The FileSystemWatcher class is designed to detected changes in the filesystem. It can be parametrised with the Filter and Path Property. Example: FileSystemWatcher w = new FileSystemWatcher(); w.Filter = "*.txt"; w.Path = @"C:\Windows"; The Filter property is only used to check the pattern of a file name. So do not use a directory path there. You can add methods such as the WaitForChanged(..) to watch for changes in the specified area. Path class - MSDN The System.IO.Path class has many useful static methods for creating and parsing resource paths. ErrorEventArgs class and ErrorEventHandler delegate ErrorEventArgs class - MSDN ErrorEventHandler delegate - MSDN RenamedEventArgs class and RenamedEventHandler delegate RenamedEventArgs class - MSDN RenamedEventHandler delegate - MSDN Byte streams Exam objective: Manage byte streams by using Stream classes. (Refer System.IO namespace) FileStream class - MSDN Stream class - MSDN System.IO.Stream is the abstract base class that all other streams inherit from. It is not possible in instantiate a Stream class. Instead use one of the other classes that derive from Stream. In terms of the 70-536 exam objectives, the most important classes that inherit from Stream are: System.IO.FileStream System.IO.MemoryStream System.IO.Compression.DeflateStream System.IO.Compression.GZipStream System.Security.Cryptography.CryptoStream System.IO.BufferedStream For a complete list of classes that inherit from Stream see MSDN. For a discussion on File and Stream IO see MSDN. MemoryStream class - MSDN BufferedStream class - MSDN Reader and Writer classes Exam objective: Manage the .NET Framework application data by using Reader and Writer classes. (Refer System.IO namespace) StringReader class and StringWriter class - MSDN and MSDN StringReader and StringWriter inherit from TextReader/TextWriter. StringReader is a TextReader for strings. StringWriter is a TextWriter for strings. TextReader class and TextWriter class TextReader class - MSDN TextReader and TextWriter are abstract base classes that StreamReader, StreamWriter, StringReader, and StringWriter derive from. StreamReader and StringReader derive from TextReader. StreamWriter and StringWriter derive from TextWriter. TextWriter class - MSDN StreamReader class and StreamWriter class - MSDN and MSDN The StreamReader and StreamWriter classes provide basic functionality for reading and writing to character-based streams (ReadLine(), WriteLine(), ReadToEnd()). StreamReader and StreamWriter inherit from the abstract classes TextReader and TextWriter: StreamReader is a TextReader of streams. StreamWriter is a TextWriter of streams. The Peek and the Read method of a StreamReader: The Peek-method gets the character at a certain position, but does not advance. The Read-method gets the character at a certain position and advances. BinaryReader class and BinaryWriter class BinaryReader class - MSDN BinaryWriter class - MSDN Compression and isolated storage Exam objective: Compress or decompress stream information in a .NET Framework application and improve the security of application data by using isolated storage. (Refer System.IO.Compression namespace) (Refer System.IO.IsolatedStorage namespace) IsolatedStorageFile class - MSDN IsolatedStorageFileStream class - MSDN DeflateStream class - MSDN GZipStream class - MSDN Previous / Next