问如何使用C#计算段落中某个单词的数量

EN

int wordCount = Regex.Matches(text, "\\b" + Regex.Escape(searchTerm) + "\\b", RegexOptions.IgnoreCase).Count;

class CountWords
{
    static void Main()
    {
        string text = @"Historically, the world of data and the world of objects" +
          @" have not been well integrated. Programmers work in C# or Visual Basic" +
          @" and also in SQL or XQuery. On the one side are concepts such as classes," +
          @" objects, fields, inheritance, and .NET Framework APIs. On the other side" +
          @" are tables, columns, rows, nodes, and separate languages for dealing with" +
          @" them. Data types often require translation between the two worlds; there are" +
          @" different standard functions. Because the object world has no notion of query, a" +
          @" query can only be represented as a string without compile-time type checking or" +
          @" IntelliSense support in the IDE. Transferring data from SQL tables or XML trees to" +
          @" objects in memory is often tedious and error-prone.";

        string searchTerm = "data";

        //Convert the string into an array of words 
        string[] source = text.Split(new char[] { '.', '?', '!', ' ', ';', ':', ',' }, StringSplitOptions.RemoveEmptyEntries);

        // Create the query.  Use ToLowerInvariant to match "data" and "Data"  
        var matchQuery = from word in source
                         where word.ToLowerInvariant() == searchTerm.ToLowerInvariant()
                         select word;

        // Count the matches, which executes the query. 
        int wordCount = matchQuery.Count();
        Console.WriteLine("{0} occurrences(s) of the search term \"{1}\" were found.", wordCount, searchTerm);

        // Keep console window open in debug mode
        Console.WriteLine("Press any key to exit");
        Console.ReadKey();
    }
}
/* Output:
   3 occurrences(s) of the search term "data" were found.
*/

String test = "the full full :full? text !!! ";
String search = "full";
int count = String.Concat(test.Select(i => Char.IsPunctuation(i) ? ' ' : i))
                  .Split(' ').Where(i => i == search).Count();