From Xojo Documentation

Class (inherits from RuntimeException)

Raised when an IO error occurs using BinaryStream, TextOutputStream, or TextInputStream.

CallStack Message Stack
ErrorNumber Stack
CallStack Stack


The IOException represents errors that can occur while using the shared methods for opening and creating streams: BinaryStream.Open, BinaryStream.Create, TextOutputStream.Create, TextOutputStream.Append, and TextInputStream.Open. If you are using older APIs, you need to check the FolderItem.LastErrorCode property.

Error Codes

The ErrorNumber property of an IOException may be set to an OS error code.


The Apple doc page for NSError lists all error codes.


Windows error codes are available at MSDN.


Linux error codes are defined in a header file, errno.h.

Sample Code

The following example catches an IOException if it occurs.

Dim f As FolderItem = GetSaveFolderItem(FileTypes1.Text, "Create Example.txt")
If f <> Nil Then
Dim t As TextOutputStream = TextOutputStream.Create(f) // this line could raise an IOException.
End If

Exception err As IOException
MsgBox("an IO exception occurred")

See Also

BinaryStream, RuntimeException, TextInputStream, TextOutputStream classes.