对象数组转化DataSet并导出到文本

         public static DataSet ObjectArrayToDataSet(object[] objArr)
         {
             if (objArr.Length == 0)
                 return null;
             DataSet ds = CreateDataSet(objArr[0].GetType());
             ds = FillDataSet(ds, objArr);
             string path="E:\\学习文档\\dataset.txt";
             string title="";
              EduceToTxTFromSql(ds, path, title);
             return ds;
         }

         public static DataSet CreateDataSet(Type t)
         {
             DataSet ds = new DataSet();
             DataTable dt = new DataTable();
             ds.Tables.Add(dt);

             PropertyInfo[] pis = t.GetProperties();
             foreach (PropertyInfo pi in pis)
             {
                 DataColumn dc = new DataColumn(pi.Name, pi.PropertyType);
                 dt.Columns.Add(dc);
             }
             return ds;
         }

         public static DataSet FillDataSet(DataSet ds, object[] objArr)
         {
             DataColumnCollection dcs = ds.Tables[0].Columns;
             Type t = objArr[0].GetType();
             foreach (object obj in objArr)
             {
                 DataRow dr = ds.Tables[0].NewRow();
                 for (int i = 0; i < dcs.Count; i++)
                 {
                     dr[i] = t.InvokeMember(dcs[i].ColumnName, BindingFlags.GetProperty, null, obj, null);
                 }
                 ds.Tables[0].Rows.Add(dr);
             }
             return ds;
         }

  //导出文本              
        public static void EduceToTxTFromSql(DataSet ds, string path, string title)
        {

            System.Data.DataTable dt = ds.Tables[0];
            //创建要导出信息的流【先创建一个流（根据具体情况创建什么流），再创建流的处理对象（读或者写）】
            FileStream fs = new FileStream(path, FileMode.Create, FileAccess.ReadWrite);
            StreamWriter sw = new StreamWriter(fs);
            //写入标题
            sw.Write(title);
            sw.WriteLine();
            //写入信息
            string s = " | ";
            foreach (DataRow dr in dt.Rows)
            {
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    string str = "str" + j;
                    str = dr[j].ToString();
                    sw.Write(str);
                    sw.Write(s);
                }
                sw.WriteLine();
            }
            sw.Flush();
            sw.Close();
        }