TextFieldParser Class

 
System_CAPS_noteNote

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Provides methods and properties for parsing structured text files.

Namespace:   Microsoft.VisualBasic.FileIO
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

System.Object
  Microsoft.VisualBasic.FileIO.TextFieldParser

public class TextFieldParser : IDisposable

NameDescription
System_CAPS_pubmethodTextFieldParser(Stream)

Initializes a new instance of the TextFieldParser class.

System_CAPS_pubmethodTextFieldParser(Stream, Encoding)

Initializes a new instance of the TextFieldParser class.

System_CAPS_pubmethodTextFieldParser(Stream, Encoding, Boolean)

Initializes a new instance of the TextFieldParser class.

System_CAPS_pubmethodTextFieldParser(Stream, Encoding, Boolean, Boolean)

Initializes a new instance of the TextFieldParser class.

System_CAPS_pubmethodTextFieldParser(String)

Initializes a new instance of the TextFieldParser class.

System_CAPS_pubmethodTextFieldParser(String, Encoding)

Initializes a new instance of the TextFieldParser class.

System_CAPS_pubmethodTextFieldParser(String, Encoding, Boolean)

Initializes a new instance of the TextFieldParser class.

System_CAPS_pubmethodTextFieldParser(TextReader)

Initializes a new instance of the TextFieldParser class.

NameDescription
System_CAPS_pubpropertyCommentTokens

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.

System_CAPS_pubpropertyDelimiters

Defines the delimiters for a text file.

System_CAPS_pubpropertyEndOfData

Returns True if there are no non-blank, non-comment lines between the current cursor position and the end of the file.

System_CAPS_pubpropertyErrorLine

Returns the line that caused the most recent MalformedLineException exception.

System_CAPS_pubpropertyErrorLineNumber

Returns the number of the line that caused the most recent MalformedLineException exception.

System_CAPS_pubpropertyFieldWidths

Denotes the width of each column in the text file being parsed.

System_CAPS_pubpropertyHasFieldsEnclosedInQuotes

Denotes whether fields are enclosed in quotation marks when a delimited file is being parsed.

System_CAPS_pubpropertyLineNumber

Returns the current line number, or returns -1 if no more characters are available in the stream.

System_CAPS_pubpropertyTextFieldType

Indicates whether the file to be parsed is delimited or fixed-width.

System_CAPS_pubpropertyTrimWhiteSpace

Indicates whether leading and trailing white space should be trimmed from field values.

NameDescription
System_CAPS_pubmethodClose()

Closes the current TextFieldParser object.

System_CAPS_pubmethodDispose()

Releases resources used by the TextFieldParser object.

System_CAPS_protmethodDispose(Boolean)

Releases resources used by the TextFieldParser object.

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows the TextFieldParser object to attempt to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Overrides Object.Finalize().)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethodPeekChars(Int32)

Reads the specified number of characters without advancing the cursor.

System_CAPS_pubmethodReadFields()

Reads all fields on the current line, returns them as an array of strings, and advances the cursor to the next line containing data.

System_CAPS_pubmethodReadLine()

Returns the current line as a string and advances the cursor to the next line.

System_CAPS_pubmethodReadToEnd()

Reads the remainder of the text file and returns it as a string.

System_CAPS_pubmethodSetDelimiters(String[])

Sets the delimiters for the reader to the specified values, and sets the field type to Delimited.

System_CAPS_pubmethodSetFieldWidths(Int32[])

Sets the delimiters for the reader to the specified values.

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

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 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 in Visual Basic

Read from a fixed-width text file

How to: Read From Fixed-width Text Files in Visual Basic

Read from a text file with multiple formats

How to: Read From Text Files with Multiple Formats in Visual Basic

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

.NET Framework
Available since 2.0

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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