比较文件 把2.txt里面包含1.txt的行过滤掉

 1string newhao = "";
 2            string[] haoList1 = file1("1.txt", "\r\n");
 3            string[] haoList2 = file1("2.txt", "\r\n");
 4            DataTable dt = new DataTable();
 5            dt.Columns.Add("hao", typeof(string));
 6            for (int i = 1; i < haoList1.Length; i++)
 7            {
 8                DataRow dr = dt.NewRow();
 9                dr["hao"] = haoList1[i];
10                dt.Rows.Add(dr);
11            }
12            haoList1 = null;
13            DataTable dt2 = new DataTable();
14            dt2.Columns.Add("hao", typeof(string));
15            for (int i = 1; i < haoList2.Length; i++)
16            {
17                DataRow dr = dt2.NewRow();
18                dr["hao"] = haoList2[i];
19                dt2.Rows.Add(dr);
20            }
21            haoList2 = null;
22            // string sql = "select* from dt where  not exists(select 1 from dt2 where dt.yhao = dt2.ghao)";
23            var normalReceive = dt2.AsEnumerable().Except(dt.AsEnumerable(), DataRowComparer.Default);
24 
25            foreach (var item in normalReceive)
26            {
27                label2.Text = (++x).ToString();
28                newhao += item["hao"].ToString()+"\r\n";
29 
30                //lock (fileLock)
31                //{
32                if (x%10000==0)
33                {
34                    using (StreamWriter sw = new StreamWriter("new1.txt", true))
35                    {
36                        sw.WriteLine(newhao);
37                    }
38                    newhao = "";
39                }
40                // }
41 
42            }
43            using (StreamWriter sw = new StreamWriter("new1.txt", true))
44            {
45                sw.WriteLine(newhao);
46            }