C#中使用NPOI匯入匯出CSV檔案

標籤：turn   options   reader   return   dtc   csv   datatable   else   app   

1.首先（NPOI官網下載dll）

添加引用：NPOI.dll，NPOI.OOXML.dll，NPOI.OpenXml4Net.dll，NPOI.OpenXmlFormats.dll

2.代碼——CSVHelper

  1     public class CSVHelper  2     {  3         /// <summary>  4         /// 寫入CSV  5         /// </summary>  6         /// <param name="fileName">檔案名稱</param>  7         /// <param name="dt">要寫入的datatable</param>  8         public static void WriteCSV(string fileName,DataTable dt)  9         { 10             FileStream fs; 11             StreamWriter sw; 12             string data = null; 13  14             //判斷檔案是否存在,存在就不再次寫入列名 15             if (!File.Exists(fileName)) 16             { 17                  fs = new FileStream(fileName, FileMode.Create, FileAccess.Write); 18                  sw = new StreamWriter(fs, Encoding.UTF8);  19  20                 //寫出列名稱 21                 for (int i = 0; i < dt.Columns.Count; i++) 22                 { 23                      data += dt.Columns[i].ColumnName.ToString(); 24                     if (i < dt.Columns.Count - 1) 25                     { 26                         data += ",";//中間用，隔開 27                     } 28                 } 29                 sw.WriteLine(data); 30             } 31             else 32             { 33                  fs = new FileStream(fileName, FileMode.Append, FileAccess.Write); 34                  sw = new StreamWriter(fs, Encoding.UTF8);  35             } 36              37             //寫出各行資料 38             for (int i = 0; i < dt.Rows.Count; i++) 39             { 40                 data = null; 41                 for (int j = 0; j < dt.Columns.Count; j++) 42                 { 43                     data += dt.Rows[i][j].ToString(); 44                     if (j < dt.Columns.Count - 1) 45                     { 46                         data += ",";//中間用，隔開 47                     } 48                 } 49                 sw.WriteLine(data); 50             }  51             sw.Close(); 52             fs.Close();  53         } 54  55  56  57         /// <summary> 58         /// 讀取CSV檔案 59         /// </summary> 60         /// <param name="fileName">檔案路徑</param> 61         public static DataTable ReadCSV(string fileName) 62         { 63             DataTable dt = new DataTable(); 64             FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); 65             StreamReader sr = new StreamReader(fs, Encoding.UTF8); 66  67             //記錄每次讀取的一行記錄 68             string strLine = null; 69             //記錄每行記錄中的各欄位內容 70             string[] arrayLine=null; 71             //分隔字元 72             string[] separators = { "," }; 73             //判斷，若是第一次，建立表頭 74             bool isFirst = true; 75  76             //逐行讀取CSV檔案 77             while ((strLine = sr.ReadLine()) != null) 78             { 79                 strLine = strLine.Trim();//去除頭尾空格 80                 arrayLine = strLine.Split(separators, StringSplitOptions.RemoveEmptyEntries);//分隔字串，返回數組 81                 int dtColumns = arrayLine.Length;//列的個數 82  83                 if (isFirst)  //建立表頭 84                 { 85                     for (int i = 0; i < dtColumns; i++) 86                     { 87                         dt.Columns.Add(arrayLine[i]);//每一列名稱 88                     } 89                 } 90                 else   //表內容 91                 { 92                     DataRow dataRow = dt.NewRow();//建立一行 93                     for (int j = 0; j < dtColumns; j++) 94                     { 95                         dataRow[j] = arrayLine[j]; 96                     } 97                     dt.Rows.Add(dataRow);//添加一行 98                 } 99             }100             sr.Close();101             fs.Close();102 103             return dt;104         }

 

C#中使用NPOI匯入匯出CSV檔案