C#体贴之处点滴 - extention method, lambda expression, anonymous method

说的是C#如何体贴程序员,而非.NET Framework。

 

这是C#对Delegate相关领域下的精微功夫:    
List<Product> products = Product.GetSampleProducts();
foreach (Product product in products.OrderBy(p => p.Name))    //entention method
{
  Console.WriteLine (product);
}

 

上面的代码等价于下面的,如何,C#体贴不?
List<Product> products = Product.GetSampleProducts();
products.Sort((x, y) => x.Name.CompareTo(y.Name));   //lambda expression
foreach (Product product in products)
{
  Console.WriteLine(product);
}

 

上面的代码等价于下面的,如何,C#体贴不?
List<Product> products = Product.GetSampleProducts();
products.Sort(delegate(Product x, Product y)  //anonymous method
{

  return x.Name.CompareTo(y.Name); }
);
foreach (Product product in products)
{
  Console.WriteLine(product);
}

 

上面的代码逻辑上等价于下面的,如何,C#体贴不?
class ProductNameComparer : IComparer<Product>  //裸奔流?
{
  public int Compare(Product x, Product y)
  {
    return x.Name.CompareTo(y.Name);
  }
}
...
List<Product> products = Product.GetSampleProducts();
products.Sort(new ProductNameComparer());
foreach (Product product in products)
{
  Console.WriteLine(product);
}

 

最后,附上LINQ Query的代码,相信无人不知,不过为了文气的完整,得罗嗦一下,好在这样的代码实在太养眼了。

List<Product> products = Product.GetSampleProducts();
var sorted =  from p in products     //体贴不?
        orderby p.Name
          select p;
foreach (Product product in sorted)
{
  Console.WriteLine(product);
}

 

(按:code source from <<C# in Depth>> 2nd.Edition Jon Skeet)

posted @ 2011-10-21 08:55  James Leng  阅读(449)  评论(0编辑  收藏  举报