FileSystem.Loc(Int32) Method

Reference

Definition

Namespace:: Microsoft.VisualBasic

Assembly:: Microsoft.VisualBasic.Core.dll

Assembly:: Microsoft.VisualBasic.dll

Source:: FileSystem.vb

Source:: FileSystem.vb

Source:: FileSystem.vb

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Returns a value that specifies the current read/write position in an open file.

public:
 static long Loc(int FileNumber);

public static long Loc (int FileNumber);

static member Loc : int -> int64

Public Function Loc (FileNumber As Integer) As Long

Parameters

FileNumber: Int32

Required. Any valid Integer file number.

Returns

Int64

The current read/write position in an open file.

Exceptions

IOException

File mode is invalid.

Examples

This example uses the Loc function to return the current read/write position in an open file. This example assumes that MyFile is a text file that has several lines of sample data.

Dim location As Long
Dim oneChar As Char
FileOpen(1, "C:\TESTFILE.TXT", OpenMode.Binary)
While location < LOF(1)
    Input(1, oneChar)
    location = Loc(1)
    WriteLine(1, location & ControlChars.CrLf)
End While
FileClose(1)

Remarks

The Loc function is zero-based; using it to retrieve the first byte in a file will return 0.

The Loc function is provided for backward compatibility and may affect performance. For non-legacy applications, the My.Computer.FileSystem object provides better performance. For more information, see File Access with Visual Basic.

The following describes the return value for each file access mode:

Mode	Return value
`Random`	Number of the last record read from or written to the file.
`Sequential`	Current byte position in the file divided by 128. However, information returned by `Loc` for sequential files is neither used nor required.
`Binary`	Position of the last byte read or written.

Applies to

Поділитися через