func openDBFfile(_ filename: String) -> Bool

This function opens DBF file. It accepts a string and returns a boolean value, true if everything was good.
Do not forget to close your file if you do not need it anymore.

{
    let dbf = cdbfapi()
    if dbf <> nil { return }

    if dbf.openDBFfile("c:\\tmp\\example.dbf")
    {
        // your code
        dbf.closeDBFFile()
    }
}