我想阅读CSV文件的内容并创建数据集。 我这样想：
var lines = File.ReadAllLines("test.csv").Select(a => a.Split(';'));
DataSet ds = new DataSet();
ds.load(lines);
但显然这是不正确的。
答案 0 :(得分：20)
您需要添加引用 Microsoft.VisualBasic.dll 才能使用TextFieldParser类。
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;
}
}
有关详细信息，请参阅此文章：http://www.morgantechspace.com/2013/08/how-to-read-data-from-csv-file-in-c.html
答案 1 :(得分：15)
您需要针对CSV文件运行SELECT语句以填充数据集：
编辑：这是http://carllbrown.blogspot.co.uk/2007/09/populate-dataset-from-csv-delimited_18.html
的一些示例代码string FileName = ...
OleDbConnection conn = new OleDbConnection
("Provider=Microsoft.Jet.OleDb.4.0; Data Source = " +
Path.GetDirectoryName(FileName) +
"; Extended Properties = \"Text;HDR=YES;FMT=Delimited\"");
conn.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter
("SELECT * FROM " + Path.GetFileName(FileName), conn);
DataSet ds = new DataSet("Temp");
adapter.Fill(ds);
conn.Close();
答案 2 :(得分：4)
您可以使用像Fast CSV Reader那样的库
using System.IO;
using LumenWorks.Framework.IO.Csv;
void ReadCsv()
{
// open the file "data.csv" which is a CSV file with headers
using (CsvReader csv = new CsvReader(
new StreamReader("data.csv"), true))
{
myDataRepeater.DataSource = csv;
myDataRepeater.DataBind();
}
}
答案 3 :(得分：1)
此代码中解决的逗号（，）问题
即使您在单元格之间添加逗号（，）
也可以阅读CSV文件代码：
public MainWindow()
{
InitializeComponent();
DataTable dtDataSource = new DataTable();
string[] fileContent = File.ReadAllLines(@"..\\Book1.csv");
if (fileContent.Count() > 0)
{
//Create data table columns dynamically
string[] columns = fileContent[0].Split(',');
for (int i = 0; i < columns.Count(); i++)
{
dtDataSource.Columns.Add(columns[i]);
}
//Add row data dynamically
for (int i = 1; i < fileContent.Count(); i++)
{
string[] rowData = fileContent[i].Split(',');
string[] realRowData = new string[columns.Count()];
StringBuilder collaboration = new StringBuilder();
int v = 0;
//this region solves the problem of a cell containing ",".
#region CommaSepProblem
for (int j = 0, K = 0; j < rowData.Count(); j++, K++)
{
if ((rowData[j].Count(x => x == '"') % 2 == 0))//checks if the string contains even number of DoubleQuotes
{
realRowData[K] = quotesLogic((rowData[j]));
}
else if ((rowData[j].Count(x => x == '"') % 2 != 0))//If Number of DoubleQuotes are ODD
{
int c = rowData[j].Count(x => x == '"');
v = j;
while (c % 2 != 0)//Go through all the next array cell till it makes EVEN Number of DoubleQuotes.
{
collaboration.Append(rowData[j] + ",");
j++;
c += rowData[j].Count(x => x == '"');
}
collaboration.Append(rowData[j]);
realRowData[K] = quotesLogic(collaboration.ToString());
}
else { continue; }
}
#endregion
dtDataSource.Rows.Add(realRowData);
}
if (dtDataSource != null)
{
//dataGridView1 = new DataGridView();
dataGrid1.ItemsSource = dtDataSource.DefaultView;
}
}
}
方法需要添加：
string quotesLogic(string collaboration)
{
StringBuilder after = new StringBuilder(collaboration);
if (after.ToString().StartsWith("\"") && after.ToString().EndsWith("\""))//removes 1st and last quotes as those are system generated
{
after.Remove(0, 1);
after.Remove(after.Length - 1, 1);
int count = after.Length - 1;
//FACT: if you try to add DoubleQuote in a cell in excel. It'll save that quote as 2 times DoubleQuote(Like "") which means first DoubleQuote is to give instruction to CPU that the next DoubleQuote is not system generated.
while (count > 0)//This loop find twice insertion of 2 DoubleQuotes and neutralise them to One DoubleQuote.
{
if (after[count] == '"' && after[count - 1] == '"')
{
after.Remove(count, 1);
}
count--;
}
}
return after.ToString();
}
答案 4 :(得分：0)
如果您只是想快速创建一个填充了CSV文件中的样本数据的DataTable（或直接从Excel粘贴）来玩游戏或原型，那么您可以使用我的Shan Carter先生的数据转换器 - 我最近添加了将逗号和制表符分隔的数据输出到C＃DataTable的功能。
答案 5 :(得分：0)
下面我写了五个方法，将Csv文件转换为DataTable。
它们的设计考虑了可选的引号（例如“符号”），并且在不使用其他库的情况下尽可能多样化：
public static DataTable GetDataTabletFromCSVFile(string filePath, bool isHeadings)
{
DataTable MethodResult = null;
try
{
using (TextFieldParser TextFieldParser = new TextFieldParser(filePath))
{
if (isHeadings)
{
MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);
}
else
{
MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);
}
}
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
public static DataTable GetDataTableFromCsvString(string csvBody, bool isHeadings)
{
DataTable MethodResult = null;
try
{
MemoryStream MemoryStream = new MemoryStream();
StreamWriter StreamWriter = new StreamWriter(MemoryStream);
StreamWriter.Write(csvBody);
StreamWriter.Flush();
MemoryStream.Position = 0;
using (TextFieldParser TextFieldParser = new TextFieldParser(MemoryStream))
{
if (isHeadings)
{
MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);
}
else
{
MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);
}
}
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
public static DataTable GetDataTableFromRemoteCsv(string url, bool isHeadings)
{
DataTable MethodResult = null;
try
{
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
StreamReader StreamReader = new StreamReader(httpWebResponse.GetResponseStream());
using (TextFieldParser TextFieldParser = new TextFieldParser(StreamReader))
{
if (isHeadings)
{
MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);
}
else
{
MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);
}
}
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
private static DataTable GetDataTableFromTextFieldParser(TextFieldParser textFieldParser)
{
DataTable MethodResult = null;
try
{
textFieldParser.SetDelimiters(new string[] { "," });
textFieldParser.HasFieldsEnclosedInQuotes = true;
string[] ColumnFields = textFieldParser.ReadFields();
DataTable dt = new DataTable();
foreach (string ColumnField in ColumnFields)
{
DataColumn DataColumn = new DataColumn(ColumnField);
DataColumn.AllowDBNull = true;
dt.Columns.Add(DataColumn);
}
while (!textFieldParser.EndOfData)
{
string[] Fields = textFieldParser.ReadFields();
for (int i = 0; i < Fields.Length; i++)
{
if (Fields[i] == "")
{
Fields[i] = null;
}
}
dt.Rows.Add(Fields);
}
MethodResult = dt;
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
private static DataTable GetDataTableFromTextFieldParserNoHeadings(TextFieldParser textFieldParser)
{
DataTable MethodResult = null;
try
{
textFieldParser.SetDelimiters(new string[] { "," });
textFieldParser.HasFieldsEnclosedInQuotes = true;
bool FirstPass = true;
DataTable dt = new DataTable();
while (!textFieldParser.EndOfData)
{
string[] Fields = textFieldParser.ReadFields();
if(FirstPass)
{
for (int i = 0; i < Fields.Length; i++)
{
DataColumn DataColumn = new DataColumn("Column " + i);
DataColumn.AllowDBNull = true;
dt.Columns.Add(DataColumn);
}
FirstPass = false;
}
for (int i = 0; i < Fields.Length; i++)
{
if (Fields[i] == "")
{
Fields[i] = null;
}
}
dt.Rows.Add(Fields);
}
MethodResult = dt;
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
如果像我一样，您正在保存报告服务，那么您应该像这样使用它：
Warning[] warnings;
string[] streamids;
string mimeType;
string encoding;
string filenameExtension;
byte[] bytes = rvMain.ServerReport.Render("csv", null, out mimeType, out encoding, out filenameExtension, out streamids, out warnings);
string CsvBody = System.Text.Encoding.UTF8.GetString(bytes);
DataTable dt = GetDataTableFromCsvString(CsvBody,true);
否则，您只需要：
bool IsHeadings = true; //Does the data include a heading row?
DataTable dt = GetDataTableFromCsvString(CsvBody, IsHeadings);
或直接从csv文件中使用
bool IsHeadings = true; //Does the data include a heading row?
DataTable dt = GetDataTabletFromCsvFile(FilePath, IsHeadings)
或者使用远程存储的csv文件
bool IsHeadings = true; //Does the data include a heading row?
DataTable dt = GetDataTabletFromRemoteCsv(Url, IsHeadings)
数据集是DataTables的集合，因此请创建一个如下：
DataSet ds = new DataSet();
ds.Tables.Add(dt);