From Xojo Documentation

Property (As Boolean )
aOpenFileDialog.AllowMultipleSelections = newBooleanValue
BooleanValue = aOpenFileDialog.AllowMultipleSelections

New in 2019r2

Supported for all project types and targets.

If True, the dialog supports multiple file selections. The default is False.


ShowModal still returns a FolderItem, but in the case of a AllowMultipleSelections OpenFileDialog, the FolderItem returned will be the first selection. To obtain a list of all the selected FolderItems, use the SelectedFiles to iterate through them.

Sample Code

Let user choose multiple files and displays them in a Listbox:

Var dlg As New OpenFileDialog
dlg.ActionButtonCaption = "Select Files"
dlg.CancelButtonCaption = "Cancel"
dlg.SuggestedFileName = ""
dlg.Title = "Select Files"
dlg.PromptText = "Select one or more files"
dlg.InitialFolder = SpecialFolder.Documents
dlg.AllowMultipleSelections = True
Var f As FolderItem = dlg.ShowModal

For Each file As Folderitem In dlg.SelectedFiles