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
仍然是错误的。你需要对引号中的""进行补偿。 这是我的解决方案微软风格csv。
/// <summary>
/// Microsoft style csv file. " is the quote character, "" is an escaped quote.
/// </summary>
/// <param name="fileName"></param>
/// <param name="sepChar"></param>
/// <param name="quoteChar"></param>
/// <param name="escChar"></param>
/// <returns></returns>
public static List<string[]> ReadCSVFileMSStyle(string fileName, char sepChar = ',', char quoteChar = '"')
{
List<string[]> ret = new List<string[]>();
string[] csvRows = System.IO.File.ReadAllLines(fileName);
foreach (string csvRow in csvRows)
{
bool inQuotes = false;
List<string> fields = new List<string>();
string field = "";
for (int i = 0; i < csvRow.Length; i++)
{
if (inQuotes)
{
// Is it a "" inside quoted area? (escaped litteral quote)
if(i < csvRow.Length - 1 && csvRow[i] == quoteChar && csvRow[i+1] == quoteChar)
{
i++;
field += quoteChar;
}
else if(csvRow[i] == quoteChar)
{
inQuotes = false;
}
else
{
field += csvRow[i];
}
}
else // Not in quoted region
{
if (csvRow[i] == quoteChar)
{
inQuotes = true;
}
if (csvRow[i] == sepChar)
{
fields.Add(field);
field = "";
}
else
{
field += csvRow[i];
}
}
}
if (!string.IsNullOrEmpty(field))
{
fields.Add(field);
field = "";
}
ret.Add(fields.ToArray());
}
return ret;
}
}
其他回答
您可以使用c#中的Microsoft.VisualBasic.FileIO.TextFieldParser dll来获得更好的性能
从上面的文章中获取下面的代码示例
static void Main()
{
string csv_file_path=@"C:\Users\Administrator\Desktop\test.csv";
DataTable csvData = GetDataTabletFromCSVFile(csv_file_path);
Console.WriteLine("Rows count:" + csvData.Rows.Count);
Console.ReadLine();
}
private static DataTable GetDataTabletFromCSVFile(string csv_file_path)
{
DataTable csvData = new DataTable();
try
{
using(TextFieldParser csvReader = new TextFieldParser(csv_file_path))
{
csvReader.SetDelimiters(new string[] { "," });
csvReader.HasFieldsEnclosedInQuotes = true;
string[] colFields = csvReader.ReadFields();
foreach (string column in colFields)
{
DataColumn datecolumn = new DataColumn(column);
datecolumn.AllowDBNull = true;
csvData.Columns.Add(datecolumn);
}
while (!csvReader.EndOfData)
{
string[] fieldData = csvReader.ReadFields();
//Making empty value as null
for (int i = 0; i < fieldData.Length; i++)
{
if (fieldData[i] == "")
{
fieldData[i] = null;
}
}
csvData.Rows.Add(fieldData);
}
}
}
catch (Exception ex)
{
}
return csvData;
}
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();
仍然是错误的。你需要对引号中的""进行补偿。 这是我的解决方案微软风格csv。
/// <summary>
/// Microsoft style csv file. " is the quote character, "" is an escaped quote.
/// </summary>
/// <param name="fileName"></param>
/// <param name="sepChar"></param>
/// <param name="quoteChar"></param>
/// <param name="escChar"></param>
/// <returns></returns>
public static List<string[]> ReadCSVFileMSStyle(string fileName, char sepChar = ',', char quoteChar = '"')
{
List<string[]> ret = new List<string[]>();
string[] csvRows = System.IO.File.ReadAllLines(fileName);
foreach (string csvRow in csvRows)
{
bool inQuotes = false;
List<string> fields = new List<string>();
string field = "";
for (int i = 0; i < csvRow.Length; i++)
{
if (inQuotes)
{
// Is it a "" inside quoted area? (escaped litteral quote)
if(i < csvRow.Length - 1 && csvRow[i] == quoteChar && csvRow[i+1] == quoteChar)
{
i++;
field += quoteChar;
}
else if(csvRow[i] == quoteChar)
{
inQuotes = false;
}
else
{
field += csvRow[i];
}
}
else // Not in quoted region
{
if (csvRow[i] == quoteChar)
{
inQuotes = true;
}
if (csvRow[i] == sepChar)
{
fields.Add(field);
field = "";
}
else
{
field += csvRow[i];
}
}
}
if (!string.IsNullOrEmpty(field))
{
fields.Add(field);
field = "";
}
ret.Add(fields.ToArray());
}
return ret;
}
}
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
这里有一个特殊的情况,其中一个数据字段有分号(“;”)作为它的数据的一部分,在这种情况下,上面的大多数答案将失败。
这种情况下的解决方案是
string[] csvRows = System.IO.File.ReadAllLines(FullyQaulifiedFileName);
string[] fields = null;
List<string> lstFields;
string field;
bool quoteStarted = false;
foreach (string csvRow in csvRows)
{
lstFields = new List<string>();
field = "";
for (int i = 0; i < csvRow.Length; i++)
{
string tmp = csvRow.ElementAt(i).ToString();
if(String.Compare(tmp,"\"")==0)
{
quoteStarted = !quoteStarted;
}
if (String.Compare(tmp, ";") == 0 && !quoteStarted)
{
lstFields.Add(field);
field = "";
}
else if (String.Compare(tmp, "\"") != 0)
{
field += tmp;
}
}
if(!string.IsNullOrEmpty(field))
{
lstFields.Add(field);
field = "";
}
// This will hold values for each column for current row under processing
fields = lstFields.ToArray();
}