我正在读取*.csv文件。
*.csv-file由分号(";")分隔的两列组成。
我能够阅读*.csv文件使用StreamReader,并能够通过使用Split()函数分离每一行。我想将每一列存储到一个单独的数组中,然后显示它。
有可能做到吗?
我正在读取*.csv文件。
*.csv-file由分号(";")分隔的两列组成。
我能够阅读*.csv文件使用StreamReader,并能够通过使用Split()函数分离每一行。我想将每一列存储到一个单独的数组中,然后显示它。
有可能做到吗?
当前回答
LINQ:
var lines = File.ReadAllLines("test.txt").Select(a => a.Split(';'));
var csv = from line in lines
select (from piece in line
select piece);
^^错误-尼克编辑
原来的应答者似乎试图用一个2维数组填充csv -一个包含数组的数组。第一个数组中的每一项都包含一个表示行号的数组,嵌套数组中的每一项都包含该特定列的数据。
var csv = from line in lines
select (line.Split(',')).ToArray();
其他回答
这是我的2个简单的静态方法,将文本从csv文件转换为列表<列表<字符串>>,反之亦然。每种方法都使用行转换器。
这段代码应该考虑csv文件的所有可能性。您可以定义自己的csv分隔符,该方法尝试纠正转义双引号字符,并处理当所有文本在引号中是一个单元格,csv分隔符在引号字符串中,包括一个单元格中的多行,可以忽略空行。
最后一种方法仅用于测试。所以你可以忽略它,或者用这个测试方法测试你自己的或别人的解决方案:)。为了测试,我使用了这个硬csv, 4行2行:
0,a,""bc,d
"e, f",g,"this,is, o
ne ""lo
ng, cell""",h
这是最终代码。为了简单起见,我删除了所有的try catch块。
using System;
using System.Collections.Generic;
using System.Linq;
public static class Csv {
public static string FromListToString(List<List<string>> csv, string separator = ",", char quotation = '"', bool returnFirstRow = true)
{
string content = "";
for (int row = 0; row < csv.Count; row++) {
content += (row > 0 ? Environment.NewLine : "") + RowFromListToString(csv[row], separator, quotation);
}
return content;
}
public static List<List<string>> FromStringToList(string content, string separator = ",", char quotation = '"', bool returnFirstRow = true, bool ignoreEmptyRows = true)
{
List<List<string>> csv = new List<List<string>>();
string[] rows = content.Split(new string[] { Environment.NewLine }, StringSplitOptions.None);
if (rows.Length <= (returnFirstRow ? 0 : 1)) { return csv; }
List<string> csvRow = null;
for (int rowIndex = 0; rowIndex < rows.Length; rowIndex++) {
(List<string> row, bool rowClosed) = RowFromStringToList(rows[rowIndex], csvRow, separator, quotation);
if (rowClosed) { if (!ignoreEmptyRows || row.Any(rowItem => rowItem.Length > 0)) { csv.Add(row); csvRow = null; } } // row ok, add to list
else { csvRow = row; } // not fully created, continue
}
if (!returnFirstRow) { csv.RemoveAt(0); } // remove header
return csv;
}
public static string RowFromListToString(List<string> csvData, string separator = ",", char quotation = '"')
{
csvData = csvData.Select(element =>
{
if (element.Contains(quotation)) {
element = element.Replace(quotation.ToString(), quotation.ToString() + quotation.ToString());
}
if (element.Contains(separator) || element.Contains(Environment.NewLine)) {
element = "\"" + element + "\"";
}
return element;
}).ToList();
return string.Join(separator, csvData);
}
public static (List<string>, bool) RowFromStringToList(string csvRow, List<string> continueWithRow = null, string separator = ",", char quotation = '"')
{
bool rowClosed = true;
if (continueWithRow != null && continueWithRow.Count > 0) {
// in previous result quotation are fixed so i need convert back to double quotation
string previousCell = quotation.ToString() + continueWithRow.Last().Replace(quotation.ToString(), quotation.ToString() + quotation.ToString()) + Environment.NewLine;
continueWithRow.RemoveAt(continueWithRow.Count - 1);
csvRow = previousCell + csvRow;
}
char tempQuote = (char)162;
while (csvRow.Contains(tempQuote)) { tempQuote = (char)(tempQuote + 1); }
char tempSeparator = (char)(tempQuote + 1);
while (csvRow.Contains(tempSeparator)) { tempSeparator = (char)(tempSeparator + 1); }
csvRow = csvRow.Replace(quotation.ToString() + quotation.ToString(), tempQuote.ToString());
if(csvRow.Split(new char[] { quotation }, StringSplitOptions.None).Length % 2 == 0) { rowClosed = !rowClosed; }
string[] csvSplit = csvRow.Split(new string[] { separator }, StringSplitOptions.None);
List<string> csvList = csvSplit
.ToList()
.Aggregate("",
(string row, string item) => {
if (row.Count((ch) => ch == quotation) % 2 == 0) { return row + (row.Length > 0 ? tempSeparator.ToString() : "") + item; }
else { return row + separator + item; }
},
(string row) => row.Split(tempSeparator).Select((string item) => item.Trim(quotation).Replace(tempQuote, quotation))
).ToList();
if (continueWithRow != null && continueWithRow.Count > 0) {
return (continueWithRow.Concat(csvList).ToList(), rowClosed);
}
return (csvList, rowClosed);
}
public static bool Test()
{
string csvText = "0,a,\"\"bc,d" + Environment.NewLine + "\"e, f\",g,\"this,is, o" + Environment.NewLine + "ne \"\"lo" + Environment.NewLine + "ng, cell\"\"\",h";
List<List<string>> csvList = new List<List<string>>() { new List<string>() { "0", "a", "\"bc", "d" }, new List<string>() { "e, f", "g", "this,is, o" + Environment.NewLine + "ne \"lo" + Environment.NewLine + "ng, cell\"", "h" } };
List<List<string>> csvTextAsList = Csv.FromStringToList(csvText);
bool ok = Enumerable.SequenceEqual(csvList[0], csvTextAsList[0]) && Enumerable.SequenceEqual(csvList[1], csvTextAsList[1]);
string csvListAsText = Csv.FromListToString(csvList);
return ok && csvListAsText == csvText;
}
}
使用例子:
// get List<List<string>> representation of csv
var csvFromText = Csv.FromStringToList(csvAsText);
// read csv file with custom separator and quote
// return no header and ignore empty rows
var csvFile = File.ReadAllText(csvFileFullPath);
var csvFromFile = Csv.FromStringToList(csvFile, ";", '"', false, false);
// get text representation of csvData from List<List<string>>
var csvAsText = Csv.FromListToString(csvData);
注: 这:char tempQuote = (char)162;是ASCI表中的第一个稀有字符。脚本会搜索这个字符,或者不是文本中的第一个接下来的几个ascii字符,并将其用作临时转义和引用字符。
以下是我对投票最多的答案的修改:
var contents = File.ReadAllText(filename).Split('\n');
var csv = from line in contents
select line.Split(',').ToArray();
csv变量可以像下面的例子那样使用:
int headerRows = 5;
foreach (var row in csv.Skip(headerRows)
.TakeWhile(r => r.Length > 1 && r.Last().Trim().Length > 0))
{
String zerothColumnValue = row[0]; // leftmost column
var firstColumnValue = row[1];
}
刚刚发现了这个库:https://github.com/JoshClose/CsvHelper
非常直观,易于使用。有一个nuget包也使快速实现:https://www.nuget.org/packages/CsvHelper/27.2.1。我很喜欢这种积极的保养。
将其配置为使用分号很容易:https://github.com/JoshClose/CsvHelper/wiki/Custom-Configurations
我通常从codeproject中使用这个解析器,因为它为我处理了一堆字符转义和类似的东西。
我最喜欢的CSV解析器是内置于. net库中的。这是微软内部隐藏的宝藏。VisualBasic名称空间。 下面是一个示例代码:
using Microsoft.VisualBasic.FileIO;
var path = @"C:\Person.csv"; // Habeeb, "Dubai Media City, Dubai"
using (TextFieldParser csvParser = new TextFieldParser(path))
{
csvParser.CommentTokens = new string[] { "#" };
csvParser.SetDelimiters(new string[] { "," });
csvParser.HasFieldsEnclosedInQuotes = true;
// Skip the row with the column names
csvParser.ReadLine();
while (!csvParser.EndOfData)
{
// Read current line fields, pointer moves to the next line.
string[] fields = csvParser.ReadFields();
string Name = fields[0];
string Address = fields[1];
}
}
记得添加对微软的引用。VisualBasic
关于解析器的更多细节请参见:http://codeskaters.blogspot.ae/2015/11/c-easiest-csv-parser-built-in-net.html