Linq.cs 1.4 KB

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  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. /// <summary>
  6. ///
  7. /// </summary>
  8. public partial class Utils
  9. {
  10. }
  11. /// <summary>
  12. /// 扩展下Linq,增加一个取随机值方法. wanggangzero@vip.qq.coms
  13. /// </summary>
  14. public static class LinqExt
  15. {
  16. static Random r = new Random(Guid.NewGuid().GetHashCode()); // 随机种子
  17. /// <summary>
  18. /// 从集合中随机取一批数据
  19. /// </summary>
  20. /// <typeparam name="T"></typeparam>
  21. /// <param name="source"></param>
  22. /// <param name="count"></param>
  23. /// <returns></returns>
  24. public static IEnumerable<T> Random<T>(this IEnumerable<T> source, int? count = null)
  25. {
  26. return count.HasValue ? source.OrderBy(_ => r.Next()).Take(count.Value) : source.OrderBy(_ => r.Next());
  27. }
  28. /// <summary>
  29. /// 仿PHP的implode函数
  30. /// </summary>
  31. /// <param name="source"></param>
  32. /// <param name="glue"></param>
  33. /// <returns></returns>
  34. public static string Implode(this IEnumerable<string> source, string glue = "")
  35. {
  36. var sb = new StringBuilder();
  37. var n = source.Count();
  38. int i = 0;
  39. source.ToList().ForEach(s => sb.Append((++i < n) ? s + glue : s));
  40. return sb.ToString();
  41. }
  42. public static string[] Explode(this string strSource, string seperator = ""){
  43. return strSource.Split(new string[] { seperator }, StringSplitOptions.RemoveEmptyEntries);
  44. }
  45. }