datatable去重

DataTable dt = new DataTable();

DataColumn c1 = new DataColumn("CompanyName", typeof(string));//公司名称

DataColumn c2 = new DataColumn("MainBusiness", typeof(string));//公司业务

DataColumn c3 = new DataColumn("SaleName", typeof(string));//销售人员

dt.Columns.AddRange(new DataColumn[]{c1,c2,c3});

DataRow r1 = dt.NewRow();

r1["CompanyName"] = "公司A";

r1["MainBusiness"] = "公司A业务";

r1["SaleName"] = "张三";

dt.Rows.Add(r1);

DataRow r2 = dt.NewRow();

r2["CompanyName"] = "公司A";

r2["MainBusiness"] = "公司A业务";

r2["SaleName"] = "李四";

dt.Rows.Add(r2);

DataRow r3 = dt.NewRow();

r3["CompanyName"] = "公司B";

r3["MainBusiness"] = "公司B业务";

r3["SaleName"] = "王五";

dt.Rows.Add(r3);

//去重处理

DataView dv = new DataView(dt);

DataTable resutl = dv.ToTable(true, new string[]{"CompanyName","MainBusiness"});

Response.Write(resutl.Rows.Count);