Linq使用(2)

DataTable或者List <ComInfo>中的数据是：

Company  CaseNum   

中国台湾  0001

中国台湾  0002

中国台湾  0002

香港      0001

香港      0001

要求结果:

Company  Totala  Totalb

中国台湾  3    2

香港      2    1

注：按company分组，取得组数(Totala),然后再按company+CaseNum分组，取得组数(Totalb)

这是从网上看到了一组数据， 通过对文章的了解，自己写了一个算法，虽然可以跟原作者相差不大，但是还是要写一下。

 

public partial class LinqDistinct : System.Web.UI.Page
  {
      protected void Page_Load(object sender, EventArgs e)
      {
          List<ComInfo> lit=GetList();
          var jlit=from x in lit group x by x.Company into y
                   select new ComLay { ComName = y.Key, ATotal = y.Count(),BTotal=y.Distinct(new ComInfoComparer()).Count()};
          GridView1.DataSource = jlit;
          GridView1.DataBind();
      }

      public List<ComInfo> GetList()
      {
          List<ComInfo> lt=new List<ComInfo>();
          ComInfo cinfo=new ComInfo();
          cinfo.Company="中国台湾";
          cinfo.CaseNum="0001";
          lt.Add(cinfo);
          cinfo = new ComInfo();
          cinfo.Company="中国台湾";
          cinfo.CaseNum="0002";
          lt.Add(cinfo);
          cinfo = new ComInfo();
          cinfo.Company="中国台湾";
          cinfo.CaseNum="0002";
          lt.Add(cinfo);
          cinfo = new ComInfo();
          cinfo.Company="香港";
          cinfo.CaseNum="0001";
          lt.Add(cinfo);
          cinfo = new ComInfo();
           cinfo.Company="香港";
           cinfo.CaseNum="0001";
           lt.Add(cinfo);

           return lt;
      }
  }

     public class ComLay
      {
           public string ComName
           {
               get;
               set;
           }

           public int ATotal
           {
               get;
               set;
           }

          public int BTotal
          {
              get;
              set;
          }
      }
  public class ComInfo
  {
       public string Company
       {
           get;
           set;
       }

       public string CaseNum
       {
          get;
          set;
       }
  }

  public class ComInfoComparer : IEqualityComparer<ComInfo>
  {
      #region IEqualityComparer<ComInfo> Members
      bool IEqualityComparer<ComInfo>.Equals(ComInfo x, ComInfo y)
      {
             if (x.CaseNum.Equals(y.CaseNum) && x.Company.Equals(y.Company))
                return true;
             return false;
      }

      int IEqualityComparer<ComInfo>.GetHashCode(ComInfo obj)
      {
          return (obj.CaseNum + obj.Company).GetHashCode();
      }
      #endregion
  }

 

通过ComInfoComparer ,可以按照类来进行Distinct