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
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。
其他回答
大家好，我为此创建了一个静态类。 +列检查 +配额符号移除
public static class CSV
{
public static List<string[]> Import(string file, char csvDelimiter, bool ignoreHeadline, bool removeQuoteSign)
{
return ReadCSVFile(file, csvDelimiter, ignoreHeadline, removeQuoteSign);
}
private static List<string[]> ReadCSVFile(string filename, char csvDelimiter, bool ignoreHeadline, bool removeQuoteSign)
{
string[] result = new string[0];
List<string[]> lst = new List<string[]>();
string line;
int currentLineNumner = 0;
int columnCount = 0;
// Read the file and display it line by line.
using (System.IO.StreamReader file = new System.IO.StreamReader(filename))
{
while ((line = file.ReadLine()) != null)
{
currentLineNumner++;
string[] strAr = line.Split(csvDelimiter);
// save column count of dirst line
if (currentLineNumner == 1)
{
columnCount = strAr.Count();
}
else
{
//Check column count of every other lines
if (strAr.Count() != columnCount)
{
throw new Exception(string.Format("CSV Import Exception: Wrong column count in line {0}", currentLineNumner));
}
}
if (removeQuoteSign) strAr = RemoveQouteSign(strAr);
if (ignoreHeadline)
{
if(currentLineNumner !=1) lst.Add(strAr);
}
else
{
lst.Add(strAr);
}
}
}
return lst;
}
private static string[] RemoveQouteSign(string[] ar)
{
for (int i = 0;i< ar.Count() ; i++)
{
if (ar[i].StartsWith("\"") || ar[i].StartsWith("'")) ar[i] = ar[i].Substring(1);
if (ar[i].EndsWith("\"") || ar[i].EndsWith("'")) ar[i] = ar[i].Substring(0,ar[i].Length-1);
}
return ar;
}
}
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();
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。
看看这个
使用CsvFramework;
使用System.Collections.Generic;
命名空间 CvsParser {
public class Customer
{
public int Id { get; set; }
public string Name { get; set; }
public List<Order> Orders { get; set; }
}
public class Order
{
public int Id { get; set; }
public int CustomerId { get; set; }
public int Quantity { get; set; }
public int Amount { get; set; }
public List<OrderItem> OrderItems { get; set; }
}
public class Address
{
public int Id { get; set; }
public int CustomerId { get; set; }
public string Name { get; set; }
}
public class OrderItem
{
public int Id { get; set; }
public int OrderId { get; set; }
public string ProductName { get; set; }
}
class Program
{
static void Main(string[] args)
{
var customerLines = System.IO.File.ReadAllLines(@"Customers.csv");
var orderLines = System.IO.File.ReadAllLines(@"Orders.csv");
var orderItemLines = System.IO.File.ReadAllLines(@"OrderItemLines.csv");
CsvFactory.Register<Customer>(builder =>
{
builder.Add(a => a.Id).Type(typeof(int)).Index(0).IsKey(true);
builder.Add(a => a.Name).Type(typeof(string)).Index(1);
builder.AddNavigation(n => n.Orders).RelationKey<Order, int>(k => k.CustomerId);
}, false, ',', customerLines);
CsvFactory.Register<Order>(builder =>
{
builder.Add(a => a.Id).Type(typeof(int)).Index(0).IsKey(true);
builder.Add(a => a.CustomerId).Type(typeof(int)).Index(1);
builder.Add(a => a.Quantity).Type(typeof(int)).Index(2);
builder.Add(a => a.Amount).Type(typeof(int)).Index(3);
builder.AddNavigation(n => n.OrderItems).RelationKey<OrderItem, int>(k => k.OrderId);
}, true, ',', orderLines);
CsvFactory.Register<OrderItem>(builder =>
{
builder.Add(a => a.Id).Type(typeof(int)).Index(0).IsKey(true);
builder.Add(a => a.OrderId).Type(typeof(int)).Index(1);
builder.Add(a => a.ProductName).Type(typeof(string)).Index(2);
}, false, ',', orderItemLines);
var customers = CsvFactory.Parse<Customer>();
}
}
}
您不能立即创建数组，因为您需要从一开始就知道行数(这将需要读取csv文件两次)。
您可以将值存储在两个List<T>中，然后使用它们或使用List<T>.ToArray()将它们转换为数组
非常简单的例子:
var column1 = new List<string>();
var column2 = new List<string>();
using (var rd = new StreamReader("filename.csv"))
{
while (!rd.EndOfStream)
{
var splits = rd.ReadLine().Split(';');
column1.Add(splits[0]);
column2.Add(splits[1]);
}
}
// print column1
Console.WriteLine("Column 1:");
foreach (var element in column1)
Console.WriteLine(element);
// print column2
Console.WriteLine("Column 2:");
foreach (var element in column2)
Console.WriteLine(element);
N.B.
请注意，这只是一个非常简单的例子。使用字符串。Split不考虑某些记录包含分隔符的情况;在里面。 为了更安全的方法，可以考虑使用一些特定于csv的库，比如nuget上的CsvHelper。
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