CSharp: Decorator Pattern in donet 6

 

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/// <summary>     ///装饰模式 Decorator Pattern  亦称： 装饰者模式、装饰器模式、Wrapper、Decorator     /// </summary>     public interface IDataSource     {           /// <summary>         ///         /// </summary>         /// <param name="data"></param>         void Write(string data);         /// <summary>         ///         /// </summary>         /// <returns></returns>         string Read();         /// <summary>         ///         /// </summary>         void ClearContent();     }      /// <summary>     /// 装饰模式 Decorator Pattern  亦称： 装饰者模式、装饰器模式、Wrapper、Decorator     /// </summary>     public class File : IDataSource     {           /// <summary>         ///         /// </summary>         private readonly string _name;         /// <summary>         ///         /// </summary>         private readonly StringBuilder _data;         /// <summary>         ///         /// </summary>         /// <param name="name"></param>         public File(string name)         {             _name = name;             _data = new StringBuilder();         }         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         public void Write(string data)         {             _data.Append(data);               Console.WriteLine($"写入文件: {_name}");             Console.WriteLine($"写成: {data}");         }         /// <summary>         ///         /// </summary>         /// <returns></returns>         public string Read() => _data.ToString();         /// <summary>         ///         /// </summary>         public void ClearContent() => _data.Clear();     }   using Geovin.Du.DuDecorator.DataStorage.Components.Common; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;   namespace Geovin.Du.DuDecorator.DataStorage.Decorators.Common {       /// <summary>     /// 装饰模式 Decorator Pattern  亦称： 装饰者模式、装饰器模式、Wrapper、Decorator     /// </summary>     public abstract class DataSourceDecorator : IDataSource     {           /// <summary>         ///         /// </summary>         protected readonly IDataSource _wrapee;         /// <summary>         ///         /// </summary>         /// <param name="dataSource"></param>         protected DataSourceDecorator(IDataSource dataSource)         {             _wrapee = dataSource;         }           // The base decorator simply delegates all work to the wrapped component.         // Extra behaviors can be added in concrete decorators.         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         public virtual void Write(string data) =>             _wrapee.Write(data);           // With this approach, concrete decorators can call the parent implementation of the operation         // instead of calling the wrapped object directly.         // That simplifies extension of decorator classes.         /// <summary>         ///         /// </summary>         /// <returns></returns>         public virtual string Read() =>             _wrapee.Read();         /// <summary>         ///         /// </summary>         public void ClearContent() => _wrapee.ClearContent();     } }     /// <summary>     /// 装饰模式 Decorator Pattern  亦称： 装饰者模式、装饰器模式、Wrapper、Decorator     /// </summary>     public class CompressionDecorator : DataSourceDecorator     {           /// <summary>         ///         /// </summary>         private readonly string _compressionBlock;         /// <summary>         ///         /// </summary>         /// <param name="wrapee"></param>         public CompressionDecorator(IDataSource wrapee)             : base(wrapee)         {             _compressionBlock = "--COMPRESSED--";         }         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         public override void Write(string data)         {             Console.WriteLine("压缩");               var compressedData = Compress(data);             _wrapee.Write(compressedData);         }         /// <summary>         ///         /// </summary>         /// <returns></returns>         public override string Read()         {             var compressedData = _wrapee.Read();             return Decompress(compressedData);         }         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         /// <returns></returns>         private string Compress(string data) =>             $"{_compressionBlock}{data}{_compressionBlock}";         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         /// <returns></returns>         private string Decompress(string data) =>             data.Replace(_compressionBlock, string.Empty, StringComparison.InvariantCulture);     }      /// <summary>     /// 装饰模式 Decorator Pattern  亦称： 装饰者模式、装饰器模式、Wrapper、Decorator     /// </summary>     public class EncryptionDecorator : DataSourceDecorator     {           /// <summary>         ///         /// </summary>         private readonly string _encryptionBlock;         /// <summary>         ///         /// </summary>         /// <param name="wrapee"></param>         public EncryptionDecorator(IDataSource wrapee)             : base(wrapee)         {             _encryptionBlock = "##3NCRYPT3D##";         }         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         public override void Write(string data)         {             Console.WriteLine("加密");               var encryptedData = Encrypt(data);             _wrapee.Write(encryptedData);         }         /// <summary>         ///         /// </summary>         /// <returns></returns>         public override string Read()         {             var encryptedData = _wrapee.Read();             return Decrypt(encryptedData);         }         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         /// <returns></returns>         private string Encrypt(string data) =>             $"{_encryptionBlock}{data}{_encryptionBlock}";         /// <summary>         ///         /// </summary>         /// <param name="data"></param>         /// <returns></returns>         private string Decrypt(string data) =>             data.Replace(_encryptionBlock, string.Empty, StringComparison.InvariantCulture);           }    /// <summary>     /// 装饰模式 Decorator Pattern  亦称： 装饰者模式、装饰器模式、Wrapper、Decorator     /// </summary>     public static class DataStorageExecutor     {         /// <summary>         ///         /// </summary>         public static void Execute()         {             ConsoleExtension.WriteSeparator("装饰模式 Decorator Pattern--Data storage demo");               ProcessFileWithPlainData();             ProcessFileWithCompressedData();             ProcessFileWithCompressedAndEncryptedData();         }         /// <summary>         ///         /// </summary>         private static void ProcessFileWithPlainData()         {             IDataSource source = new Components.File("file.dat");               WriteAndRead(source);         }         /// <summary>         ///         /// </summary>         private static void ProcessFileWithCompressedData()         {             IDataSource source = new Components.File("file.dat");             source = new CompressionDecorator(source);               WriteAndRead(source);         }         /// <summary>         ///         /// </summary>         private static void ProcessFileWithCompressedAndEncryptedData()         {             IDataSource source = new Components.File("file.dat");             source = new EncryptionDecorator(source);             source = new CompressionDecorator(source);               WriteAndRead(source);         }         /// <summary>         ///         /// </summary>         /// <param name="source"></param>         private static void WriteAndRead(IDataSource source)         {             source.Write("Hello world");             Console.WriteLine($"Read: {source.Read()}\n");         }     }

　　

调用：

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1 2	Geovin.Du.DuDecorator.DataStorage.DataStorageExecutor.Execute();      Console.WriteLine();

　　

输出：

 

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Hello, Geovin Du! 学习 .net 6   装饰模式 Decorator Pattern--Data storage demo -------------------------------------------------- 写入文件: file.dat 写成: Hello world Read: Hello world   压缩 写入文件: file.dat 写成: --COMPRESSED--Hello world--COMPRESSED-- Read: Hello world   压缩 加密 写入文件: file.dat 写成: ##3NCRYPT3D##--COMPRESSED--Hello world--COMPRESSED--##3NCRYPT3D## Read: Hello world