一、DataTable数据写入CSV文件

public static void SaveCSV(DataTable dt, string fullPath)//table数据写入csv{ System.IO.FileInfo fi = new System.IO.FileInfo(fullPath); if (!fi.Directory.Exists) { fi.Directory.Create(); } System.IO.FileStream fs = new System.IO.FileStream(fullPath, System.IO.FileMode.Create, System.IO.FileAccess.Write); System.IO.StreamWriter sw = new System.IO.StreamWriter(fs, System.Text.Encoding.UTF8); string data = ""; for (int i = 0; i < dt.Columns.Count; i++)//写入列名 { data += dt.Columns[i].ColumnName.ToString(); if (i < dt.Columns.Count - 1) { data += ","; } } sw.WriteLine(data); for (int i = 0; i < dt.Rows.Count; i++) //写入各行数据 { data = ""; for (int j = 0; j < dt.Columns.Count; j++) { string str = dt.Rows[i][j].ToString(); str = str.Replace("\"", "\"\"");//替换英文冒号 英文冒号需要换成两个冒号 if (str.Contains(',') || str.Contains('"') || str.Contains('\r') || str.Contains('\n')) //含逗号 冒号 换行符的需要放到引号中 { str = string.Format("\"{0}\"", str); } data += str; if (j < dt.Columns.Count - 1) { data += ","; } } sw.WriteLine(data); } sw.Close(); fs.Close();}

二、读取CSV文件到DataTable

public static DataTable OpenCSV(string filePath)//从csv读取数据返回table{ System.Text.Encoding encoding = GetType(filePath); //Encoding.ASCII;// DataTable dt = new DataTable(); System.IO.FileStream fs = new System.IO.FileStream(filePath, System.IO.FileMode.Open, System.IO.FileAccess.Read); System.IO.StreamReader sr = new System.IO.StreamReader(fs, encoding); //记录每次读取的一行记录 string strLine = ""; //记录每行记录中的各字段内容 string[] aryLine = null; string[] tableHead = null; //标示列数 int columnCount = 0; //标示是否是读取的第一行 bool IsFirst = true; //逐行读取CSV中的数据 while ((strLine = sr.ReadLine()) != null) { if (IsFirst == true) { tableHead = strLine.Split(','); IsFirst = false; columnCount = tableHead.Length; //创建列 for (int i = 0; i < columnCount; i++) { DataColumn dc = new DataColumn(tableHead[i]); dt.Columns.Add(dc); } } else { aryLine = strLine.Split(','); DataRow dr = dt.NewRow(); for (int j = 0; j < columnCount; j++) { dr[j] = aryLine[j]; } dt.Rows.Add(dr); } } if (aryLine != null && aryLine.Length > 0) { dt.DefaultView.Sort = tableHead[0] + " " + "asc"; } sr.Close(); fs.Close(); return dt;}/// 给定文件的路径，读取文件的二进制数据，判断文件的编码类型/// <param name="FILE_NAME">文件路径</param>/// <returns>文件的编码类型</returns> public static System.Text.Encoding GetType(string FILE_NAME){ System.IO.FileStream fs = new System.IO.FileStream(FILE_NAME, System.IO.FileMode.Open, System.IO.FileAccess.Read); System.Text.Encoding r = GetType(fs); fs.Close(); return r;} /// 通过给定的文件流，判断文件的编码类型/// <param name="fs">文件流</param>/// <returns>文件的编码类型</returns>public static System.Text.Encoding GetType(System.IO.FileStream fs){ byte[] Unicode = new byte[] { 0xFF, 0xFE, 0x41 }; byte[] UnicodeBIG = new byte[] { 0xFE, 0xFF, 0x00 }; byte[] UTF8 = new byte[] { 0xEF, 0xBB, 0xBF }; //带BOM System.Text.Encoding reVal = System.Text.Encoding.Default; System.IO.BinaryReader r = new System.IO.BinaryReader(fs, System.Text.Encoding.Default); int i; int.TryParse(fs.Length.ToString(), out i); byte[] ss = r.ReadBytes(i); if (IsUTF8Bytes(ss) || (ss[0] == 0xEF && ss[1] == 0xBB && ss[2] == 0xBF)) { reVal = System.Text.Encoding.UTF8; } else if (ss[0] == 0xFE && ss[1] == 0xFF && ss[2] == 0x00) { reVal = System.Text.Encoding.BigEndianUnicode; } else if (ss[0] == 0xFF && ss[1] == 0xFE && ss[2] == 0x41) { reVal = System.Text.Encoding.Unicode; } r.Close(); return reVal;} /// 判断是否是不带 BOM 的 UTF8 格式/// <param name="data"></param>/// <returns></returns>private static bool IsUTF8Bytes(byte[] data){ int charByteCounter = 1;　 //计算当前正分析的字符应还有的字节数 byte curByte; //当前分析的字节. for (int i = 0; i < data.Length; i++) { curByte = data[i]; if (charByteCounter == 1) { if (curByte >= 0x80) { //判断当前 while (((curByte <<= 1) & 0x80) != 0) { charByteCounter++; } //标记位首位若为非0 则至少以2个1开始 如:110XXXXX...........1111110X　 if (charByteCounter == 1 || charByteCounter > 6) { return false; } } } else { //若是UTF-8 此时第一位必须为1 if ((curByte & 0xC0) != 0x80) { return false; } charByteCounter--; } } if (charByteCounter > 1) { throw new Exception("非预期的byte格式"); } return true;}

三、修改文件名称

我们需要保存历史数据 或者实时的知道那个文件被修改 可以通过改变文件的名称 如加上当天的日期等等。

public static bool ChangeFileName(string OldPath, string NewPath) { bool re = false; try { if (File.Exists(OldPath)) { File.Move(OldPath, NewPath); re = true; } } catch { re = false; } return re;}

四、CSV文件的数据写入

直接在网页表单提交数据保存在csv文件中 直接写入文件

public static bool SaveCSV(string fullPath,string Data){ bool re = true; try { FileStream FileStream = new FileStream(fullPath, FileMode.Append); StreamWriter sw = new StreamWriter(FileStream, System.Text.Encoding.UTF8); sw.WriteLine(Data); //清空缓冲区 sw.Flush(); //关闭流 sw.Close(); FileStream.Close(); } catch { re = false; } return re;}

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