比较类字段的最佳方法
本文关键字:最佳 方法 字段 比较 | 更新日期: 2023-09-27 18:12:01
我需要有比较Product, AdvancedProduct(以及从类Product继承的其他类)的可能性如何更好地实现字段的分层检查?例如,我想检查两个AdvancedProduct类,首先检查基本类Product的字段,然后检查AdvancedProduct的附加字段,并以某种形式返回它们之间的变化(可能是类PChanges??)。是否有合适的模板?如何使这一切,但使相当灵活的后续使用?
public class Product
{
public string ID;
public string Name;
public Product(string id, string name)
{
this.ID = id;
this.Name = name;
}
}
public class AdvancedProduct : Product
{
public string CurrentVersion;
public AdvancedProduct(string id, string name, string version)
: base(id, name) { }
}
public class PChanges
{
public bool NameChanged = false;
public bool VersionChanged = false;
public PChanges() { }
}
public class ProductComparer
{
PChanges changes = new PChanges();
public ProductComparer() { }
public PChanges Compare(AdvancedProduct p1, AdvancedProduct p2)
{
if (p1.Name != p2.Name)
changes.NameChanged = true;
if (p1.CurrentVersion != p2.CurrentVersion)
changes.VersionChanged = true;
return changes;
}
}
有一个很好的。net库叫做比较。net对象。它可以用来比较复杂的对象,而不需要编写比较代码。它也是非常可定制的——你可以告诉它排除某些属性,包括其他属性,等等。它可以比较平面对象和对象层次结构。你可以从CodePlex - http://comparenetobjects.codeplex.com/下载。
根据Uzzy的回答,看起来可以扩展它来跟踪更改。这是一种糟糕的做法,但对于小型应用来说这已经足够了。例子:
public class ProductComparer : IEqualityComparer<Product>{
private PChanges change;
public PChanges Changes{ get { return change; } }
public bool Equals(Product p1, Product p2){
PChanges newChange = new PChanges();
bool equal = true;
if(p1.Name != p2.Name){
newChange.NameChange = true;
equal = false;
}
this.change = newChange;
return equal;
}
}
编辑:我误读了可扩展字段比较的要求。如果是这种情况,那么Decorator模式最适合您。假设所有其他的Product类都继承自Product类
public class ProductComparer{
public virtual void TrackChange(Product p1, Product p2, ref PChange change){
if(p1.Name != p2.Name){
change.NameChange = true;
}
// other base validation
}
}
public class AdvancedProductComparer : ProductComparer{
public AdvancedProductComparer(ProductComparer baseComparer){
this.baseComparer = baseComparer;
}
ProductComparer baseComparer;
public override void TrackChange(Product p1, Product p2, ref PChange change){
baseComparer.Compare(p1, p2, ref change);
if( ((AdvancedProduct)p1).CurrentVersion != ((AdvancedProduct)p2).CurrentVersion){
change.CurrentVersion = true;
}
}
}
public class ProductComparerService{
public ProductComparerService(ProductComparer comparer){
this.comparer = comparer;
}
ProductComparer comparer;
private PChanges change;
public PChanges Changes{ get { return change; } }
public bool Equals(Product p1, Product p2){
PChanges newChange = new PChanges();
comparer.Compare(p1,p2, ref newChange);
this.change = newChange;
return (newChange.CurrentVersion || newChange.NameChange);
}
}
用法:
ProductComparer pCompare = new ProductComparer();
AdvancedProductComparer advCompare = new AdvancedProductComparer(pCompare);
ProductComparerService service = new ProductComparerService(advCompare);
if( service.Equals(p1,p2) ){
PChange change = service.Change;
}
如果ProductComparer实现iequalaitycomparer会更好
有关详细信息,请参阅给定链接中的示例。