C＃將所有對象參數複製到子類對象

Question

假設我有一個不能更改的父類對象 - 例如，帶有長參數列表的ListBox實例。現在，我創建了一個子類：

class PlaylistBox : ListBox 
{ 

    void CopySettingsFrom(ListBox In) 
    { 
     //...what now? 
    } 
} 

問題 - 我怎樣才能高效地淺拷貝從In對象的PlaylistBox新對象？

Answer 1

您可以使用反射

//Other Imports... 
    using System.Reflection; 

    public PlaylistBox(ListBox In) 
    { 
     PropertyInfo[] properties = typeof(ListBox).GetProperties(); 

     foreach (PropertyInfo p in properties) 
      if (p.CanRead && p.CanWrite) 
       p.SetMethod.Invoke(this, new object[] { p.GetMethod.Invoke(In, null) }); 
    } 

Answer 2

這裏有3種方法的基礎上，反思和AutoMapper與解釋的例子：

internal class Program 
    { 
     private static void Main(string[] args) 
     { 
      Example1(); 
      Example2(); 
      Example3(); 
     } 

     public static void Example1() 
     { 
      Console.WriteLine("This example shows using copy with reflection. Minus of this method - u have to implement FULL copy for each class or u will copy only references to object properties"); 

      //creating new parent class with some values 
      var parentClass = new ParentClass 
      { 
       Property1 = "qqq", 
       Property2 = 1, 
       ObjectProperty = new SomeClassWithObjectProperty 
       { 
        ObjectProperty = new SomeObjectClass {SomeProperty = "www"} 
       } 
      }; 

      //crating new child class and copy REFERENCES to properties 
      var childClassReflection = new ChildClassReflection(parentClass); 

      //changing properties of parent 
      parentClass.Property1 = "rrr"; 
      parentClass.Property2 = 2; 
      parentClass.ObjectProperty.ObjectProperty.SomeProperty = "eee"; 

      //we will get OLD values for VALUE types and OLD values for REFERENCE types 
      //qqq 1 WWW 
      Console.WriteLine(childClassReflection.Property1 + " " + childClassReflection.Property2 + " " + childClassReflection.ObjectProperty.ObjectProperty.SomeProperty); 
     } 

     public static void Example2() 
     { 
      Console.WriteLine(); 
      Console.WriteLine("This example shows using copy with reflection WITH FULL COPY"); 

      //creating new parent class with some values 
      var parentClass = new ParentClass 
      { 
       Property1 = "qqq", 
       Property2 = 1, 
       ObjectProperty = new SomeClassWithObjectProperty 
       { 
        ObjectProperty = new SomeObjectClass {SomeProperty = "www"} 
       } 
      }; 

      //crating new child class and copy REFERENCES to properties 
      var childClassReflection = new ChildClassReflectionWithFullCopy(parentClass); 

      //changing properties of parent 
      parentClass.Property1 = "rrr"; 
      parentClass.Property2 = 2; 
      parentClass.ObjectProperty.ObjectProperty.SomeProperty = "eee"; 

      //we will get OLD values for VALUE types and NEW values for REFERENCE types 
      //qqq 1 eee 
      Console.WriteLine(childClassReflection.Property1 + " " + childClassReflection.Property2 + " " + childClassReflection.ObjectProperty.ObjectProperty.SomeProperty); 
     } 

     public static void Example3() 
     { 
      //here i will show copy using AutoMapper 
      Console.WriteLine(); 
      Console.WriteLine("This example shows using copy with AutoMapper"); 

      //creating new parent class with some values 
      var parentClass = new ParentClass 
      { 
       Property1 = "qqq", 
       Property2 = 1, 
       ObjectProperty = new SomeClassWithObjectProperty 
       { 
        ObjectProperty = new SomeObjectClass { SomeProperty = "www" } 
       } 
      }; 

      Mapper.Initialize(cfg => cfg.CreateMap<ParentClass, ChildClassAutoMapper>());   

      //crating new child class and copy REFERENCES to properties 
      var childClassReflection = Mapper.Map<ChildClassAutoMapper>(parentClass); 

      //changing properties of parent 
      parentClass.Property1 = "rrr"; 
      parentClass.Property2 = 2; 
      parentClass.ObjectProperty.ObjectProperty.SomeProperty = "eee"; 

      //we will get OLD values for VALUE types and OLD values for REFERENCE types 
      //qqq 1 eee 
      Console.WriteLine(childClassReflection.Property1 + " " + childClassReflection.Property2 + " " + childClassReflection.ObjectProperty.ObjectProperty.SomeProperty); 
     } 
    } 

    public class ChildClassAutoMapper:ParentClass 
    {  
    } 

    public class ChildClassReflection : ParentClass 
    { 
     public ChildClassReflection(ParentClass parentClass) 
     { 
      foreach (var p in ParentProperties) 
       p.SetMethod.Invoke(this, new[] {p.GetMethod.Invoke(parentClass, null)}); 
     } 

     //do it only once for best performance 
     private static PropertyInfo[] ParentProperties { get; } = typeof(ParentClass).GetProperties().Where(c => c.CanRead && c.CanWrite).ToArray(); 
    } 

    public class ChildClassReflectionWithFullCopy : ParentClass 
    { 
     public ChildClassReflectionWithFullCopy(ParentClass parentClass) 
     { 
      var parentClassLocal = JsonConvert.DeserializeObject<ParentClass>(JsonConvert.SerializeObject(parentClass)); 
      foreach (var p in ParentProperties) 
       p.SetMethod.Invoke(this, new[] {p.GetMethod.Invoke(parentClassLocal, null)}); 
     } 

     //do it only once for best performance 
     private static PropertyInfo[] ParentProperties { get; } = typeof(ParentClass).GetProperties().Where(c => c.CanRead && c.CanWrite).ToArray(); 
    } 

    public class ParentClass 
    { 
     public string Property1 { get; set; } 
     public int Property2 { get; set; } 
     public SomeClassWithObjectProperty ObjectProperty { get; set; } 
    } 

    public class SomeClassWithObjectProperty 
    { 
     public SomeObjectClass ObjectProperty { get; set; } 
    } 

    public class SomeObjectClass 
    { 
     public string SomeProperty { get; set; } 
    }