TextFieldParser Class
Definition
Important
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Provides methods and properties for parsing structured text files.
public ref class TextFieldParser : IDisposable
public class TextFieldParser : IDisposable
type TextFieldParser = class
interface IDisposable
Public Class TextFieldParser
Implements IDisposable
- Inheritance
-
TextFieldParser
- Implements
Examples
This example parses through a tab-delimited text file, Bigfile
.
Using MyReader As New Microsoft.VisualBasic.FileIO.
TextFieldParser("c:\logs\bigfile")
MyReader.TextFieldType =
Microsoft.VisualBasic.FileIO.FieldType.Delimited
MyReader.Delimiters = New String() {vbTab}
Dim currentRow As String()
'Loop through all of the fields in the file.
'If any lines are corrupt, report an error and continue parsing.
While Not MyReader.EndOfData
Try
currentRow = MyReader.ReadFields()
' Include code here to handle the row.
Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
MsgBox("Line " & ex.Message &
" is invalid. Skipping")
End Try
End While
End Using
Remarks
The TextFieldParser
object provides methods and properties for parsing structured text files. Parsing a text file with the TextFieldParser
is similar to iterating over a text file, while using the ReadFields
method to extract fields of text is similar to splitting the strings.
The TextFieldParser
can parse two types of files: delimited or fixed-width. Some properties, such as Delimiters
and HasFieldsEnclosedInQuotes
are meaningful only when working with delimited files, while the FieldWidths
property is meaningful only when working with fixed-width files.
The following table lists examples of tasks involving the Microsoft.VisualBasic.FileIO.TextFieldParser
object.
To | See |
---|---|
Read from a delimited text file | How to: Read From Comma-Delimited Text Files |
Read from a fixed-width text file | How to: Read From Fixed-width Text Files |
Read from a text file with multiple formats | How to: Read From Text Files with Multiple Formats |
Constructors
TextFieldParser(Stream) |
Initializes a new instance of the |
TextFieldParser(Stream, Encoding) |
Initializes a new instance of the |
TextFieldParser(Stream, Encoding, Boolean) |
Initializes a new instance of the |
TextFieldParser(Stream, Encoding, Boolean, Boolean) |
Initializes a new instance of the |
TextFieldParser(String) |
Initializes a new instance of the |
TextFieldParser(String, Encoding) |
Initializes a new instance of the |
TextFieldParser(String, Encoding, Boolean) |
Initializes a new instance of the |
TextFieldParser(TextReader) |
Initializes a new instance of the |
Properties
CommentTokens |
Defines comment tokens. A comment token is a string that, when placed at the beginning of a line, indicates that the line is a comment and should be ignored by the parser. |
Delimiters |
Defines the delimiters for a text file. |
EndOfData |
Returns |
ErrorLine |
Returns the line that caused the most recent MalformedLineException exception. |
ErrorLineNumber |
Returns the number of the line that caused the most recent MalformedLineException exception. |
FieldWidths |
Denotes the width of each column in the text file being parsed. |
HasFieldsEnclosedInQuotes |
Denotes whether fields are enclosed in quotation marks when a delimited file is being parsed. |
LineNumber |
Returns the current line number, or returns -1 if no more characters are available in the stream. |
TextFieldType |
Indicates whether the file to be parsed is delimited or fixed-width. |
TrimWhiteSpace |
Indicates whether leading and trailing white space should be trimmed from field values. |
Methods
Close() |
Closes the current |
Dispose() |
Releases resources used by the TextFieldParser object. |
Dispose(Boolean) |
Releases resources used by the TextFieldParser object. |
Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
Finalize() |
Allows the TextFieldParser object to attempt to free resources and perform other cleanup operations before it is reclaimed by garbage collection. |
GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
GetType() |
Gets the Type of the current instance. (Inherited from Object) |
MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
PeekChars(Int32) |
Reads the specified number of characters without advancing the cursor. |
ReadFields() |
Reads all fields on the current line, returns them as an array of strings, and advances the cursor to the next line containing data. |
ReadLine() |
Returns the current line as a string and advances the cursor to the next line. |
ReadToEnd() |
Reads the remainder of the text file and returns it as a string. |
SetDelimiters(String[]) |
Sets the delimiters for the reader to the specified values, and sets the field type to |
SetFieldWidths(Int32[]) |
Sets the delimiters for the reader to the specified values. |
ToString() |
Returns a string that represents the current object. (Inherited from Object) |
Explicit Interface Implementations
IDisposable.Dispose() |
Releases resources used by the TextFieldParser object. |