FolderItem.Length

From Xojo Documentation

Read-Only Property (As UInt64 )
UInt64Value = aFolderItem.Length

Supported for all project types and targets.

The size of the file’s data fork in bytes. For directories, the size will be zero.

Example

This example displays the value of Length if the open was successful.

Var f As New FolderItem
f = FolderItem.ShowOpenFileDialog("text/plain")
If f <> Nil then
MessageBox(f.Length.ToString)
End If