VB.NET BigInteger构造函数代码示例

Dim bytes() As Byte = { 5, 4, 3, 2, 1 }
Dim number As New BigInteger(bytes)
Console.WriteLine("The value of number is {0} (or 0x{0:x}).", number)

' Instantiate BigInteger values.
Dim positiveValue As BigInteger = BigInteger.Parse("4713143110832790377889")
Dim negativeValue As BigInteger = BigInteger.Add(-Int64.MaxValue, -60000) 
Dim positiveValue2, negativeValue2 As BigInteger

' Create two byte arrays.
Dim positiveBytes() As Byte = positiveValue.ToByteArray()
Dim negativeBytes() As Byte = negativeValue.ToByteArray()

' Instantiate new BigInteger from negativeBytes array.
Console.Write("Converted {0:N0} to the byte array ", negativeValue)
For Each byteValue As Byte In negativeBytes
   Console.Write("{0:X2} ", byteValue)
Next 
Console.WriteLine()
negativeValue2 = New BigInteger(negativeBytes)
Console.WriteLine("Converted the byte array to {0:N0}", negativeValue2)
Console.WriteLine()

' Instantiate new BigInteger from positiveBytes array.
Console.Write("Converted {0:N0} to the byte array ", positiveValue)
For Each byteValue As Byte In positiveBytes
   Console.Write("{0:X2} ", byteValue)
Next 
Console.WriteLine()
positiveValue2 = New BigInteger(positiveBytes)
Console.WriteLine("Converted the byte array to {0:N0}", positiveValue2)
Console.WriteLine()

Dim originalNumber As ULong = UInt64.MaxValue
' Convert an unsigned integer to a byte array.
Dim bytes() As Byte = BitConverter.GetBytes(originalNumber)
' Determine whether the MSB of the highest-order byte is set.
If originalNumber > 0 And (bytes(bytes.Length - 1) And &h80) > 0 Then
   ' If the MSB is set, add one zero-value byte to the end of the array.
   ReDim Preserve bytes(bytes.Length)
End If

Dim newNumber As New BigInteger(bytes)
Console.WriteLine("Converted the UInt64 value {0:N0} to {1:N0}.", 
                  originalNumber, newNumber)

Dim decimalValues() As Decimal = { -1790.533d, -15.1514d, 18903.79d, 9180098.003d }
For Each decimalValue As Decimal In decimalValues
   Dim number As New BigInteger(decimalValue)
   Console.WriteLine("Instantiated BigInteger value {0} from the Decimal value {1}.",
                     number, decimalValue)
Next

' Create a BigInteger from a large double value.
Dim doubleValue As Double = -6e20
Dim bigIntValue As New BigInteger(doubleValue)
Console.WriteLine("Original Double value: {0:N0}", doubleValue)
Console.WriteLine("Original BigInteger value: {0:N0}", bigIntValue)
' Increment and then display both values.
doubleValue += 1
bigIntValue += BigInteger.One
Console.WriteLine("Incremented Double value: {0:N0}", doubleValue)
Console.WriteLine("Incremented BigInteger value: {0:N0}", bigIntValue)

Dim integers() As Integer = { Int32.MinValue, -10534, -189, 0, 17, 113439,
                              Int32.MaxValue }
Dim constructed, assigned As BigInteger

For Each number As Integer In integers
   constructed = New BigInteger(number)
   assigned = number
   Console.WriteLine("{0} = {1}: {2}", constructed, assigned, 
                     constructed.Equals(assigned)) 
Next

Dim longs() As Long = { Int64.MinValue, -10534, -189, 0, 17, 113439,
                              Int64.MaxValue }
Dim constructed, assigned As BigInteger

For Each number As Long In longs
   constructed = New BigInteger(number)
   assigned = number
   Console.WriteLine("{0} = {1}: {2}", constructed, assigned, 
                     constructed.Equals(assigned)) 
Next

' Create a BigInteger from a large negative Single value
Dim negativeSingle As Single = Single.MinValue
Dim negativeNumber As New BigInteger(negativeSingle)

Console.WriteLine(negativeSingle.ToString("N0"))
Console.WriteLine(negativeNumber.ToString("N0"))

negativeSingle += 1
negativeNumber += 1
Console.WriteLine(negativeSingle.ToString("N0"))
Console.WriteLine(negativeNumber.ToString("N0"))

Dim unsignedValues() As UInteger = { 0, 16704, 199365, UInt32.MaxValue }
For Each unsignedValue As UInteger In unsignedValues
   Dim constructedNumber As New BigInteger(unsignedValue)
   Dim assignedNumber As BigInteger = unsignedValue
   If constructedNumber.Equals(assignedNumber) Then
      Console.WriteLine("Both methods create a BigInteger whose value is {0:N0}.",
                        constructedNumber)
   Else
      Console.WriteLine("{0:N0} ≠ {1:N0}", constructedNumber, assignedNumber)
   End If                         
Next

Dim unsignedValue As ULong = UInt64.MaxValue
Dim number As New BigInteger(unsignedValue)
Console.WriteLine(number.ToString("N0"))