' 导入命名空间
Imports System.Numerics

Module Example
   Public Sub Main()
      ' Create a complex number by calling its class constructor.
      Dim c1 As New Complex(12, 6)
      Console.WriteLine(c1)
      
      ' Assign a Double to a complex number.
      Dim c2 As Complex = 3.14
      Console.WriteLine(c2)
      
      ' Cast a Decimal to a complex number.
      Dim c3 As Complex = CType(12.3d, Complex)
      Console.WriteLine(c3)
      
      ' Assign the return value of a method to a Complex variable.
      Dim c4 As Complex = Complex.Pow(Complex.One, -1)
      Console.WriteLine(c4)
      
      ' Assign the value returned by an operator to a Complex variable.
      Dim c5 As Complex = Complex.One + Complex.One
      Console.WriteLine(c5)

      ' Instantiate a complex number from its polar coordinates.
      Dim c6 As Complex = Complex.FromPolarCoordinates(10, .524)
      Console.WriteLine(c6)
   End Sub
End Module

Dim value As New Complex(Double.MinValue/2, Double.MinValue/2)
Dim value2 As Complex = Complex.Exp(Complex.Log(value))
Console.WriteLine("{0} {3}{1} {3}Equal: {2}", value, value2, 
                                              value = value2,
                                              vbCrLf)

' 导入命名空间
Imports System.Numerics

Module Example
   Public Sub Main()
      Dim c1 As Complex = New Complex(Double.MaxValue / 2, Double.MaxValue /2)

      Dim c2 As Complex = c1 / Complex.Zero
      Console.WriteLine(c2.ToString())
      c2 = c2 * New Complex(1.5, 1.5)
      Console.WriteLine(c2.ToString())
      Console.WriteLine()
      
      Dim c3 As Complex = c1 * New Complex(2.5, 3.5)
      Console.WriteLine(c3.ToString())
      c3 = c3 + New Complex(Double.MinValue / 2, Double.MaxValue / 2) 
      Console.WriteLine(c3)     
   End Sub
End Module

' 导入命名空间
Imports System.Numerics

Public Class ComplexFormatter 
             Implements IFormatProvider, ICustomFormatter
   
   Public Function GetFormat(formatType As Type) As Object _
                   Implements IFormatProvider.GetFormat
      If formatType Is GetType(ICustomFormatter) Then
         Return Me
      Else
         Return Nothing
      End If
   End Function
   
   Public Function Format(fmt As String, arg As Object, 
                          provider As IFormatProvider) As String _
                   Implements ICustomFormatter.Format
      If TypeOf arg Is Complex Then
         Dim c1 As Complex = DirectCast(arg, Complex)
         ' Check if the format string has a precision specifier.
         Dim precision As Integer
         Dim fmtString As String = String.Empty
         If fmt.Length > 1 Then
            Try
               precision = Int32.Parse(fmt.Substring(1))
            Catch e As FormatException
               precision = 0
            End Try
            fmtString = "N" + precision.ToString()
         End If
         If fmt.Substring(0, 1).Equals("I", StringComparison.OrdinalIgnoreCase) Then
            Return c1.Real.ToString(fmtString) + " + " + c1.Imaginary.ToString(fmtString) + "i"
         ElseIf fmt.Substring(0, 1).Equals("J", StringComparison.OrdinalIgnoreCase) Then
            Return c1.Real.ToString(fmtString) + " + " + c1.Imaginary.ToString(fmtString) + "j"
         Else
            Return c1.ToString(fmt, provider)
         End If
      Else
         If Typeof arg Is IFormattable Then
            Return DirectCast(arg, IFormattable).ToString(fmt, provider)
         ElseIf arg IsNot Nothing Then
            Return arg.ToString()
         Else
            Return String.Empty
         End If   
      End If                        
   End Function
End Class

Module Example
   Public Sub Main()
      Dim c1 As Complex = New Complex(12.1, 15.4)
      Console.WriteLine("Formatting with ToString():       " + 
                        c1.ToString())
      Console.WriteLine("Formatting with ToString(format): " + 
                        c1.ToString("N2"))
      Console.WriteLine("Custom formatting with I0:        " + 
                        String.Format(New ComplexFormatter(), "{0:I0}", c1))
      Console.WriteLine("Custom formatting with J3:        " + 
                        String.Format(New ComplexFormatter(), "{0:J3}", c1))
   End Sub
End Module