TextFieldParser Class
Assembly: Microsoft.VisualBasic (in microsoft.visualbasic.dll)
For more detailed information, see the Visual Basic topic TextFieldParser 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 | |
| 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
This example depends on the existence of a function, processFields, which processes the fields as they are read.
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
Reference
TextFieldParser MembersMicrosoft.VisualBasic.FileIO Namespace
TextFieldParser Class
Other Resources
TextFieldParser ObjectTextFieldParser Object Members
TextFieldParser.CommentTokens Property
TextFieldParser.Delimiters Property
TextFieldParser.EndOfData Property
TextFieldParser.ErrorLine Property
TextFieldParser.ErrorLineNumber Property
TextFieldParser.FieldWidths Property
TextFieldParser.HasFieldsEnclosedInQuotes Property
TextFieldParser.LineNumber Property
TextFieldParser.TextFieldType Property
TextFieldParser.TrimWhiteSpace Property
TextFieldParser.Close Method
TextFieldParser.PeekChars Method
TextFieldParser.ReadFields Method
TextFieldParser.ReadLine Method
TextFieldParser.ReadToEnd Method
TextFieldParser.SetDelimiters Method
TextFieldParser.SetFieldWidths Method
My.Computer.FileSystem.OpenTextFieldParser Method
Parsing Text Files with the TextFieldParser Object
Troubleshooting Exceptions: Microsoft.VisualBasic.FileIO.TextFieldParser.MalformedLineException