TextFieldParser.ReadLine Method 

  • Article

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

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

Return Value

String

Exceptions

The following condition may cause an exception to be thrown:

Remarks

The ReadLine method performs no parsing; an end-of-line character within a delimited field is interpreted as the actual end of the line.

Nothing is returned if the end of the file is reached.

Example

This example reads through the file ParserText.txt and writes it 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
        Try
            currentRow = MyReader.ReadLine()
            My.Computer.FileSystem.WriteAllText _
           ("C://testfile.txt", currentRow, True)
        Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
            MsgBox("Line " & ex.Message & " is invalid.  Skipping")
        End Try
    End While
End Using

If Testfile.txt does not exist, it is created by the WriteAllText method.

This example writes the fields as a single string; to have each line display on its own line in the destination file, a VbCrLf character should be appended at the end of each line.

Requirements

Namespace: Microsoft.VisualBasic.FileIO

Class: TextFieldParser

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

Permissions

No permissions are required.

See Also

Reference

TextFieldParser Object
TextFieldParser.ReadFields Method
TextFieldParser.ReadToEnd Method
Microsoft.VisualBasic.FileIO.TextFieldParser.ReadLine

Concepts

Parsing Text Files with the TextFieldParser Object