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TextFieldParser.ReadFields Method

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

' Usage
Dim value As String() = TextFieldParserObject.ReadFields()
' Declaration
Public Function ReadFields() As String()

String ().

The following condition may cause an exception to be thrown:

In order to allow users to parse text files in multiple formats, the ReadFields method examines the values of TextFieldType, Delimiters, and FieldWidths, if they are specified, each time it is called. Users need to correctly configure the TextFieldType and FieldWidths or Delimiters properties, as appropriate. If TextFieldType is set to Delimited and Delimiters is not set, or if TextFieldType is set to FixedWidth and FieldWidths is not set, an exception is thrown.

If ReadFields encounters blank lines, they are skipped and the next non-blank line is returned.


If the ReadFields method cannot parse the current line, it raises an exception and does not move to the next line. This enables your application to attempt to parse the line again.

The following table lists examples of tasks involving the ReadFields method.

This example uses the ReadFields method to read from the file ParserText.txt and write the fields to Testfile.txt.

Using MyReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("C:\ParserText.txt")
    MyReader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
    MyReader.Delimiters = New String() {","}
    Dim currentRow As String()
    While Not MyReader.EndOfData
            currentRow = MyReader.ReadFields()
            For Each currentField As String In currentRow
                My.Computer.FileSystem.WriteAllText _
                ("C://testfile.txt", currentField, True)
        Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
            MsgBox("Line " & ex.Message & " is invalid.  Skipping")
        End Try 
    End While 
End Using

Namespace: Microsoft.VisualBasic.FileIO

Class: TextFieldParser

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)

The following permissions are required:




Associated enumeration: Unrestricted.


Associated enumeration: ControlEvidence.

For more information, see Code Access Security and Requesting Permissions.