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  • 深入理解linq的参考例子

    MSDN 站点的Linq 101[联机使用]

    http://msdn.microsoft.com/en-us/vcsharp/aa336746.aspx

    很全面的官方站点。

     

    基本概念清楚后,可以参考如下的例子以加深理解

    Linq in Action的第5章对于常用模式,性能有个综合的例子,很不错:

     

    以下是一些常见的使用场景举例  

        IEnumerable<String> titles = SampleData.Books.Select(book => book.Title);

        String[] array = titles.ToArray();

        List<String> list = titles.ToList();

        Dictionary<String, Book> isbnRef = SampleData.Books.ToDictionary(book => book.Isbn);

        Book linqRules = isbnRef["0-111-77777-2"];

        Dictionary<int, string> frenchNumbers;

        frenchNumbers = new Dictionary<int, string>();

        frenchNumbers.Add(0, "zero");

        frenchNumbers.Add(1, "un");

        frenchNumbers.Add(2, "deux");

        var evenFrenchNumbers = from entry in frenchNumbers where (entry.Key % 2) == 0 select entry.Value;

        List<Book> books = new List<Book>() {

          new Book { Title="LINQ in Action" },

          new Book { Title="LINQ for Fun" },

          new Book { Title="Extreme LINQ" } };

        var titles = books.Where(book => book.Title.Contains("Action")).Select(book => book.Title);

        var books =SampleData.Books.Select((book, index) => new { index, book.Title })

            .OrderBy(book => book.Title);

        var count = "Non-letter characters in this string: 8".Where(c => !Char.IsLetter(c)).Count();

        Object[] array = { "String", 12, true, 'a' };

        var types = array.Select(item => item.GetType().Name)

            .OrderBy(type => type);

          var query = from book in SampleData.Books

            where book.Title.Length > 10

            orderby book.Price

            select new { Book=book.Title, book.Price };

     

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  • 原文地址:https://www.cnblogs.com/2018/p/1878675.html
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