Convert.ToSByte (Double) converts double-precision floating-point number to 8-bit signed integer.
Module Example Public Sub Main() Dim numbers() As Double = { Double.MinValue, -129.5, -12.7, 0, 16, _ 103.6, Double.MaxValue} Dim result As SByte For Each number As Double In numbers Try result = Convert.ToSByte(number) Console.WriteLine(result) Catch e As OverflowException Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _ number.GetType().Name, number) End Try Next End Sub End Module