Class CsvReader

Represents a reader designed for CSV text. It is capable of deserializing objects from individual lines of CSV text, transforming CSV lines of text into objects, or simply reading the lines of CSV as an array of strings.

Inheritance

Object

CsvReader

Namespace: Swan.Formatters

Syntax

public class CsvReader : IDisposable

Examples

The following example describes how to load a list of objects from a CSV file.

using Swan.Formatters;

class Example
{
    class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    static void Main()
    {
        // load records from a CSV file
       var loadedRecords = 
       CsvReader.LoadRecords<Person>("C:\\Users\\user\\Documents\\file.csv");

        // loadedRecords = 
        //  [
        //      { Age = 20, Name = "George" }
        //      { Age = 18, Name = "Juan" }
        //  ]
    }
}

The following code explains how to read a CSV formatted string.

using Swan.Formatters;
using System.Text;
using Swan.Formatters;

class Example
{
    static void Main()
    {
        // data to be read
        var data = @"Company,OpenPositions,MainTechnology,Revenue
        Co,2,""C#, MySQL, JavaScript, HTML5 and CSS3"",500
        Ca,2,""C#, MySQL, JavaScript, HTML5 and CSS3"",600";

        using(var stream = new MemoryStream(Encoding.UTF8.GetBytes(data)))
        {
            // create a CSV reader
            var reader = new CsvReader(stream, false, Encoding.UTF8);
        }
    }
}

Constructors

CsvReader(Stream)

Initializes a new instance of the CsvReader class. It automatically closes the stream when disposing this reader and uses the Windows 1253 encoding.

Declaration

public CsvReader(Stream stream)

Parameters

Type	Name	Description
Stream	stream	The stream.

CsvReader(Stream, Encoding)

Initializes a new instance of the CsvReader class. It will automatically close the stream upon disposing.

Declaration

public CsvReader(Stream stream, Encoding textEncoding)

Parameters

Type	Name	Description
Stream	stream	The stream.
Encoding	textEncoding	The text encoding.

CsvReader(Stream, Boolean, Encoding)

Initializes a new instance of the CsvReader class.

Declaration

public CsvReader(Stream inputStream, bool leaveOpen, Encoding textEncoding)

Parameters

Type	Name	Description
Stream	inputStream	The stream.
Boolean	leaveOpen	if set to true leaves the input stream open.
Encoding	textEncoding	The text encoding.

CsvReader(String)

Initializes a new instance of the CsvReader class. It uses the Windows 1252 Encoding by default and it automatically closes the file when this reader is disposed of.

Declaration

public CsvReader(string filename)

Parameters

Type	Name	Description
String	filename	The filename.

CsvReader(String, Encoding)

Initializes a new instance of the CsvReader class. It automatically closes the file when disposing this reader.

Declaration

public CsvReader(string filename, Encoding encoding)

Parameters

Type	Name	Description
String	filename	The filename.
Encoding	encoding	The encoding.

Properties

Count

Gets number of lines that have been read, including the headings.

Declaration

public ulong Count { get; }

Property Value

Type	Description
UInt64	The count.

EndOfStream

Gets a value indicating whether the stream reader is at the end of the stream In other words, if no more data can be read, this will be set to true.

Declaration

public bool EndOfStream { get; }

Property Value

Type	Description
Boolean	true if [end of stream]; otherwise, false.

EscapeCharacter

Gets or sets the escape character. By default it is the double quote '"'.

Declaration

public char EscapeCharacter { get; set; }

Property Value

Type	Description
Char	The escape character.

SeparatorCharacter

Gets or sets the separator character. By default it is the comma character ','.

Declaration

public char SeparatorCharacter { get; set; }

Property Value

Type	Description
Char	The separator character.

Methods

Dispose()

Declaration

public void Dispose()

Dispose(Boolean)

Releases unmanaged and - optionally - managed resources.

Declaration

protected virtual void Dispose(bool disposing)

Parameters

Type	Name	Description
Boolean	disposing	true to release both managed and unmanaged resources; false to release only unmanaged resources.

LoadRecords<T>(Stream)

Loads the records from the stream This method uses Windows 1252 encoding.

Declaration

public static IList<T> LoadRecords<T>(Stream stream)
    where T : new()

Parameters

Type	Name	Description
Stream	stream	The stream.

Returns

Type	Description
IList<T>	A generic collection of objects that can be individually accessed by index.

Type Parameters

Name	Description
T	The type of IList items to load.

LoadRecords<T>(String)

Loads the records from the give file path. This method uses Windows 1252 encoding.

Declaration

public static IList<T> LoadRecords<T>(string filePath)
    where T : new()

Parameters

Type	Name	Description
String	filePath	The file path.

Returns

Type	Description
IList<T>	A generic collection of objects that can be individually accessed by index.

Type Parameters

Name	Description
T	The type of IList items to load.

ReadHeadings()

Reads a line of CSV text and stores the values read as a representation of the column names to be used for parsing objects. You have to call this method before calling ReadObject methods.

Declaration

public string[] ReadHeadings()

Returns

Type	Description
String[]	An array of the specified element type containing copies of the elements of the ArrayList.

Exceptions

Type	Condition
InvalidOperationException	Reading headings is only supported as the first read operation. or ReadHeadings.
EndOfStreamException	Cannot read past the end of the stream.

ReadLine()

Reads a line of CSV text into an array of strings.

Declaration

public string[] ReadLine()

Returns

Type	Description
String[]	An array of the specified element type containing copies of the elements of the ArrayList.

Exceptions

Type	Condition
EndOfStreamException	Cannot read past the end of the stream.

ReadObject()

Reads a line of CSV text, converting it into a dynamic object The property names correspond to the names of the CSV headings.

Declaration

public IDictionary<string, object> ReadObject()

Returns

Type	Description
IDictionary<String, Object>	Object of the type of the elements in the collection of key/value pairs.

ReadObject(IDictionary<String, String>)

Reads a line of CSV text, converting it into a dynamic object in which properties correspond to the names of the headings.

Declaration

public IDictionary<string, object> ReadObject(IDictionary<string, string> map)

Parameters

Type	Name	Description
IDictionary<String, String>	map	The mappings between CSV headings (keys) and object properties (values).

Returns

Type	Description
IDictionary<String, Object>	Object of the type of the elements in the collection of key/value pairs.

Exceptions

Type	Condition
InvalidOperationException	ReadHeadings.
EndOfStreamException	Cannot read past the end of the stream.
ArgumentNullException	map.

ReadObject<T>()

Reads a line of CSV text converting it into an object of the given type, and assuming the property names of the target type match the heading names of the file.

Declaration

public T ReadObject<T>()
    where T : new()

Returns

Type	Description
T	The conversion of specific type of object.

Type Parameters

Name	Description
T	The type of object.

ReadObject<T>(IDictionary<String, String>)

Reads a line of CSV text converting it into an object of the given type, using a map (or Dictionary) where the keys are the names of the headings and the values are the names of the instance properties in the given Type.

Declaration

public T ReadObject<T>(IDictionary<string, string> map)
    where T : new()

Parameters

Type	Name	Description
IDictionary<String, String>	map	The map of CSV headings (keys) and Type property names (values).

Returns

Type	Description
T	The conversion of specific type of object.

Type Parameters

Name	Description
T	The type of object to map.

Exceptions

Type	Condition
ArgumentNullException	map.
InvalidOperationException	ReadHeadings.
EndOfStreamException	Cannot read past the end of the stream.

ReadObject<T>(IDictionary<String, String>, ref T)

Reads a line of CSV text converting it into an object of the given type, using a map (or Dictionary) where the keys are the names of the headings and the values are the names of the instance properties in the given Type. The result object must be already instantiated.

Declaration

public void ReadObject<T>(IDictionary<string, string> map, ref T result)

Parameters

Type	Name	Description
IDictionary<String, String>	map	The map.
T	result	The result.

Type Parameters

Name	Description
T	The type of object to map.

Exceptions

Type	Condition
ArgumentNullException	map or result.
InvalidOperationException	ReadHeadings.
EndOfStreamException	Cannot read past the end of the stream.

SkipRecord()

Skips a line of CSV text. This operation does not increment the Count property and it is useful when you need to read the headings skipping over a few lines as Reading headings is only supported as the first read operation (i.e. while count is still 0).

Declaration

public void SkipRecord()

Exceptions

Type	Condition
EndOfStreamException	Cannot read past the end of the stream.

See Also

IDisposable

Comments