Convert.ToInt64 (Double) converts double-precision floating-point number to 64-bit signed integer.
Module Example Public Sub Main() Dim values() As Double = { Double.MinValue, -1.38e10, -2010.299, -12.98, _ 0, 9.113e-16, 10.19, 2010.191, Double.MaxValue } Dim result As Long For Each value As Double In values Try result = Convert.ToInt64(value) Console.WriteLine(result) Catch e As OverflowException Console.WriteLine("{0} is outside the range of the Int64 type.", value) End Try Next End Sub End Module