Binaryworld - Format a drive using an undocumented function ... [ VB -> Windows ]

SHFormatDrive is an undocumented but simple API function that allows you to format a drive. This function simply opens "Format Drive" diaolog window. Being undocument you won't find its Declare with the API Viewer utility:

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Private Declare Function SHFormatDrive Lib "Shell32.dll" (ByVal hWnd As Long, _
ByVal Drive As Integer, ByVal fmtID As Integer, ByVal Options As Integer) _
As Long

The SHFormatDrive takes four parameters. The first is the handle of the parent window. The second is the index of the drive to be formatted (A=0, B=1, C=2 …). The third should always to be set to -1. The last parameter specifies the formatting options: 0 to quick format, 1 to full format or 2 to make a system disk. The function returns a value greater than 0 if it's successful, 0 if you pass invalid parameters, -1 if an error while formatting occurs, -2 if operation is aborted, and -3 if drive cannot be formatted. Here's the sample code:

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Private Sub btnFormatDrive_Click()
  Dim ret As Long
  ' I want a full format
  ret = SHFormatDrive(Me.hWnd, cbDrive.ListIndex,-1, 1)

  Select Case ret
    Case -1
      MsgBox "Error during format operation"
    Case -2
      MsgBox "Operation canceled by user"
    Case -3
      MsgBox "This drive cannot be formatted"
    Case Else
      MsgBox "Done"
  End Select
End Sub