转换SQL到C＃：基于字符串长度

Question

我需要SQL转换为C＃人类可读的字符串截断：基于字符串长度人类可读的字符串截断

请帮我转换波纹管的SQL代码到C＃

DECLARE @String  VARCHAR(MAX), 
     @Size  TINYINT 

SELECT @String = 
     'Hello my name is Jeff. I need some help on a project because right now this is how the application i am working with displays data.', 
     @Size = 30 

;WITH Peso(Part, StartPos, SIZE) 
    AS (
     SELECT 1, 
       1, 
       CAST(
        @Size - CHARINDEX(
         ' ', 
         REVERSE(LEFT(SUBSTRING(@String, 1, @Size) + ' ', @Size)) 
        ) AS INT 
       ) 

     UNION ALL 

     SELECT Part + 1, 
       StartPos + SIZE + 1, 
       CAST(
        @Size - CHARINDEX(
         ' ', 
         REVERSE(
          LEFT(
           SUBSTRING(@String, StartPos + SIZE + 1, @Size) + 
           ' ', 
           @Size 
          ) 
         ) 
        ) AS INT 
       ) 
     FROM Peso 
     WHERE StartPos + SIZE <= DATALENGTH(@String) 
    ) 

SELECT Part, 
     SUBSTRING(@String, StartPos, SIZE) 
FROM Peso 
ORDER BY Part 

原始代码：http://weblogs.sqlteam.com/peterl/archive/2009/03/18/Human-readable-string-truncation.aspx

Answer 1

我不能从SQL将其转换为C＃，所以，我另一个代码：

public static IEnumerable<string> Split(string str, int chunkSize) 
    { 
     var list = str.Split(' ').ToList(); 
     var buildList = new List<string>(); 

     foreach (var s in list) 
     { 
      if (s.Length > chunkSize) 
      { 
       var x = SplitString(s, chunkSize); 

       buildList.AddRange(x); 
      } 
      else 
      { 
       buildList.Add(s); 
      } 
     } 

     var strResult = new List<string>(); 
     for (int i = 0; i < buildList.Count; i++) 
     { 
      strResult.Add(""); 
     } 
     int line = 0; 
     for (int i = 0; i < buildList.Count; i++) 
     { 
      if ((strResult[line] + " " + buildList[i]).Length > chunkSize + 1) 
      { 
       line++; 
       strResult[line] = buildList[i].Trim(); 
      } 
      else 
      { 
       strResult[line] = (strResult[line] + " " + buildList[i]).Trim(); 
      } 
     } 

     return strResult.Where(x => !string.IsNullOrEmpty(x)).ToList(); 
    } 

    public static IEnumerable<string> SplitString(string str, int chunkSize) 
    { 
     return str.Select((x, i) => i) 
      .Where(i => i % chunkSize == 0) 
      .Select(i => str.Substring(i, str.Length - i >= chunkSize ? chunkSize : str.Length - i)); 
    } 

而且使用像：

string text = "Hel l33 3333333333333333333933 3333333333313333333333333333333335 ause right now this is how the application i am working with displays data."; 

var ret = string.Join(Environment.NewLine, Split(text, 30)); 

编码愉快！