VB.NET BigInteger.Explicit操作符代码示例

' Explicit Decimal to BigInteger conversion
Dim decimals() As Decimal = { Decimal.MinValue, -15632.991d, 9029321.12d, 
                              Decimal.MaxValue }
Dim number As BigInteger 

Console.WriteLine("{0,35} {1,35}", "Decimal", "BigInteger")
Console.WriteLine()
For Each value As Decimal In decimals
   number = CType(value, BigInteger)
   Console.WriteLine("{0,35} {1,35}",
                     value, number)
Next

Dim doubles() As Double = { Double.MinValue, -1.430955172e03, 2.410970032e05, 
                            Double.MaxValue, Double.PositiveInfinity, 
                            Double.NegativeInfinity, Double.NaN }
Dim number As BigInteger

Console.WriteLine("{0,37} {1,37}", "Double", "BigInteger")
Console.WriteLine()
For Each value As Double In doubles
   Try
      number = CType(value, BigInteger)
      Console.WriteLine("{0,37} {1,37}", value, number)
   Catch e As OverflowException
      Console.WriteLine("{0,37} {1,37}", value, "OverflowException")
   End Try      
Next

' BigInteger to Byte conversion.
Dim goodByte As BigInteger = BigInteger.One
Dim badByte As BigInteger = 256

Dim byteFromBigInteger As Byte   

' Convert using CType function.
byteFromBigInteger = CType(goodByte, Byte)
Console.WriteLine(byteFromBigInteger)
' Convert using CByte function.
byteFromBigInteger = CByte(goodByte)
Console.WriteLine(byteFromBigInteger)

' Handle conversion that should result in overflow.
Try
   byteFromBigInteger = CType(badByte, Byte)
   Console.WriteLine(byteFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badByte, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to Decimal conversion.
Dim goodDecimal As BigInteger = 761652543
Dim badDecimal As BigInteger = CType(Decimal.MaxValue, BigInteger) 
badDecimal += BigInteger.One

Dim decimalFromBigInteger As Decimal

' Convert using CType function.
decimalFromBigInteger = CType(goodDecimal, Decimal)
Console.WriteLine(decimalFromBigInteger)
' Convert using CDec function.
decimalFromBigInteger = CDec(goodDecimal)
Console.WriteLine(decimalFromBigInteger)

' Handle conversion that should result in overflow.
Try
   decimalFromBigInteger = CType(badDecimal, Decimal)
   Console.WriteLine(decimalFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badDecimal, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to Double conversion.
Dim goodDouble As BigInteger = 102.43e22
Dim badDouble As BigInteger = CType(Double.MaxValue, BigInteger)  
badDouble = badDouble * 2

Dim doubleFromBigInteger As Double

' Convert using CType function.
doubleFromBigInteger = CType(goodDouble, Double)
Console.WriteLine(doubleFromBigInteger)
' Convert using CDbl function.
doubleFromBigInteger = CDbl(goodDouble)
Console.WriteLine(doubleFromBigInteger)

' Convert an out-of-bounds BigInteger value to a Double.
doubleFromBigInteger = CType(badDouble, Double)
Console.WriteLine(doubleFromBigInteger)

' Increase a BigInteger so it exceeds Double.MaxValue.
Dim number1 As BigInteger = CType(Double.MaxValue, BigInteger)
Dim number2 As BigInteger = number1
number2 = number2 + 9.999e291
' Compare the BigInteger values for equality.
Console.WriteLine("BigIntegers equal: {0}", number2.Equals(number1))

' Convert the BigInteger to a Double.
Dim dbl As Double = CType(number2, Double)

' Display the two values.
Console.WriteLine("BigInteger: {0}", number2)
Console.WriteLine("Double:     {0}", dbl)

' BigInteger to Int16 conversion.
Dim goodShort As BigInteger = 20000
Dim badShort As BigInteger = 33000

Dim shortFromBigInteger As Short

' Convert using CType function.
shortFromBigInteger = CType(goodShort, Short)
Console.WriteLine(shortFromBigInteger)
' Convert using CShort function.
shortFromBigInteger = CShort(goodShort)
Console.WriteLine(shortFromBigInteger)

' Handle conversion that should result in overflow.
Try
   shortFromBigInteger = CType(badShort, Short)
   Console.WriteLine(shortFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badShort, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to Int32 conversion.
Dim goodInteger As BigInteger = 200000
Dim badInteger As BigInteger = 65000000000

Dim integerFromBigInteger As Integer

' Convert using CType function.
integerFromBigInteger = CType(goodInteger, Integer)
Console.WriteLine(integerFromBigInteger)
' Convert using CInt function.
integerFromBigInteger = CInt(goodInteger)
Console.WriteLIne(integerFromBigInteger)

' Handle conversion that should result in overflow.
Try
   integerFromBigInteger = CType(badInteger, Integer)
   Console.WriteLine(integerFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badInteger, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to Int64 conversion.
Dim goodLong As BigInteger = 2000000000
Dim badLong As BigInteger = BigInteger.Pow(goodLong, 3)

Dim longFromBigInteger As Long

' Convert using CType function.
longFromBigInteger = CType(goodLong, Long)
Console.WriteLine(longFromBigInteger)
' Convert using CLng function.
longFromBigInteger = CLng(goodLong)
Console.WriteLine(longFromBigInteger)

' Handle conversion that should result in overflow.
Try
   longFromBigInteger = CType(badLong, Long)
   Console.WriteLine(longFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badLong, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to SByte conversion.
Dim goodSByte As BigInteger = BigInteger.MinusOne
Dim badSByte As BigInteger = -130

Dim sByteFromBigInteger As SByte

' Convert using CType function.
sByteFromBigInteger = CType(goodSByte, SByte)
Console.WriteLine(sByteFromBigInteger)
' Convert using CSByte function.
sByteFromBigInteger = CSByte(goodSByte)
Console.WriteLine(sByteFromBigInteger)

' Handle conversion that should result in overflow.
Try
   sByteFromBigInteger = CType(badSByte, SByte)
   Console.WriteLine(sByteFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badSByte, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to Single conversion.
Dim goodSingle As BigInteger = 102.43e22
Dim badSingle As BigInteger = CType(Single.MaxValue, BigInteger)  
badSingle = badSingle * 2

Dim singleFromBigInteger As Single

' Convert using CType function.
singleFromBigInteger = CType(goodSingle, Single)
Console.WriteLine(singleFromBigInteger)
' Convert using CSng function.
singleFromBigInteger = CSng(goodSingle)
Console.WriteLine(singleFromBigInteger)

' Convert an out-of-bounds BigInteger value to a Single.
singleFromBigInteger = CType(badSingle, Single)
Console.WriteLine(singleFromBigInteger)

' Increase a BigInteger so it exceeds Single.MaxValue.
Dim number1 As BigInteger = CType(Single.MaxValue, BigInteger)
Dim number2 As BigInteger = number1
number2 = number2 + 9.999e30
' Compare the BigInteger values for equality.
Console.WriteLine("BigIntegers equal: {0}", number2.Equals(number1))

' Convert the BigInteger to a Single.
Dim sng As Single = CType(number2, Single)

' Display the two values.
Console.WriteLine("BigInteger: {0}", number2)
Console.WriteLine("Single:     {0}", sng)

' BigInteger to UInt16 conversion.
Dim goodUShort As BigInteger = 20000
Dim badUShort As BigInteger = 66000

Dim uShortFromBigInteger As UShort

' Convert using CType function.
uShortFromBigInteger = CType(goodUShort, UShort)
Console.WriteLine(uShortFromBigInteger)
' Convert using CUShort function.
uShortFromBigInteger = CUShort(goodUShort)
Console.WriteLine(uShortFromBigInteger)

' Handle conversion that should result in overflow.
Try
   uShortFromBigInteger = CType(badUShort, UShort)
   Console.WriteLine(uShortFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badUShort, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to UInt32 conversion.
Dim goodUInteger As BigInteger = 200000
Dim badUInteger As BigInteger = 65000000000

Dim uIntegerFromBigInteger As UInteger

' Convert using CType function.
uIntegerFromBigInteger = CType(goodInteger, UInteger)
Console.WriteLine(uIntegerFromBigInteger)
' Convert using CUInt function.
uIntegerFromBigInteger = CUInt(goodInteger)
Console.WriteLine(uIntegerFromBigInteger)

' Handle conversion that should result in overflow.
Try
   uIntegerFromBigInteger = CType(badUInteger, UInteger)
   Console.WriteLine(uIntegerFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badUInteger, vbCrLf, e.Message)
End Try
Console.WriteLine()

' BigInteger to UInt64 conversion.
Dim goodULong As BigInteger = 2000000000
Dim badULong As BigInteger = BigInteger.Pow(goodULong, 3)

Dim uLongFromBigInteger As ULong

' Convert using CType function.
uLongFromBigInteger = CType(goodULong, ULong)
Console.WriteLine(uLongFromBigInteger)
' Convert using CULng function.
uLongFromBigInteger = CULng(goodULong)
Console.WriteLine(uLongFromBigInteger)

' Handle conversion that should result in overflow.
Try
   uLongFromBigInteger = CType(badULong, ULong)
   Console.WriteLine(uLongFromBigInteger)
Catch e As OverflowException
   Console.WriteLine("Unable to convert {0}:{1}   {2}", _
                     badULong, vbCrLf, e.Message)
End Try
Console.WriteLine()