作者：VB.NET开发
项目：Syste
Dim values() As Single = { Single.MinValue, -1.38e10, -1023.299, -12.98, _
0, 9.113e-16, 103.919, 17834.191, Single.MaxValue }
Dim result As Long
For Each value As Single In values
Try
result = Convert.ToInt64(value)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
value.GetType().Name, value, result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int64 type.", value)
End Try
Next
作者：VB.NET开发
项目：Syste
' Create a hexadecimal value out of range of the Long type.
Dim value As String = ULong.MaxValue.ToString("X")
' Call Convert.ToInt64 to convert it back to a number.
Try
Dim number As Long = Convert.ToInt64(value, 16)
Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
Console.WriteLine("Unable to convert '0x{0}' to a long integer.", value)
End Try
作者：VB.NET开发
项目：Syste
' Create a negative hexadecimal value out of range of the Long type.
Dim sourceNumber As ULong = ULong.MaxValue
Dim isSigned As Boolean = Math.Sign(sourceNumber.MinValue) = -1
Dim value As String = sourceNumber.ToString("X")
Dim targetNumber As Long
Try
targetNumber = Convert.ToInt64(value, 16)
If Not isSigned And ((targetNumber And &H8000000000) <> 0) Then
Throw New OverflowException()
Else
Console.WriteLine("0x{0} converts to {1}.", value, targetNumber)
End If
Catch e As OverflowException
Console.WriteLine("Unable to convert '0x{0}' to a long integer.", value)
End Try
' Displays the following to the console:
' Unable to convert '0xFFFFFFFFFFFFFFFF' to a long integer.
作者：VB.NET开发
项目：Syste
Module Example
Public Sub Main()
Dim hexStrings() As String = { "8000000000000000", "0FFFFFFFFFFFFFFF", _
"f0000000000001000", "00A30", "D", "-13", "GAD" }
For Each hexString As String In hexStrings
Try
Dim number As Long = Convert.ToInt64(hexString, 16)
Console.WriteLine("Converted '{0}' to {1:N0}.", hexString, number)
Catch e As FormatException
Console.WriteLine("'{0}' is not in the correct format for a hexadecimal number.", _
hexString)
Catch e As OverflowException
Console.WriteLine("'{0}' is outside the range of an Int64.", hexString)
Catch e As ArgumentException
Console.WriteLine("'{0}' is invalid in base 16.", hexString)
End Try
Next
End Sub
End Module
作者：VB.NET开发
项目：Syste
' 导入命名空间
Imports System.Globalization
Public Module Example
Public Sub Main()
' Create a NumberFormatInfo object and set the properties that
' affect conversions using Convert.ToInt64(String, IFormatProvider).
Dim customProvider As New NumberFormatInfo()
customProvider.NegativeSign = "neg "
customProvider.PositiveSign = "pos "
' Create an array of providers with the custom provider and the
' NumberFormatInfo object for the invariant culture.
Dim providers() As NumberFormatInfo = {customProvider, _
NumberFormatInfo.InvariantInfo }
' Define an array of strings to parse.
Dim numericStrings() As String = { "123456789", "+123456789", _
"pos 123456789", "-123456789", _
"neg 123456789", "123456789.", _
"123,456,789", "(123456789)", _
"9223372036854775808", "-9223372036854775809" }
For ctr As Integer = 0 to 1
Dim provider As IFormatProvider = providers(ctr)
Console.WriteLine(IIf(ctr = 0, "Custom Provider:", "Invariant Culture:"))
For Each numericString As String In numericStrings
Console.Write(" {0,-22} --> ", numericString)
Try
Console.WriteLine("{0,22}", Convert.ToInt32(numericString, provider))
Catch e As FormatException
Console.WriteLine("{0,22}", "Unrecognized Format")
Catch e As OverflowException
Console.WriteLine("{0,22}", "Overflow")
End Try
Next
Console.WriteLine()
Next
End Sub
End Module
作者：VB.NET开发
项目：Syste
' 导入命名空间
Imports System.Collections
Module IConvertibleProviderDemo
' Define the types of averaging available in the class
' implementing IConvertible.
Enum AverageType as Short
None = 0
GeometricMean = 1
ArithmeticMean = 2
Median = 3
End Enum
' Pass an instance of this class to methods that require an
' IFormatProvider. The class instance determines the type of
' average to calculate.
Public Class AverageInfo
Implements IFormatProvider
Protected AvgType As AverageType
' Specify the type of averaging in the constructor.
Public Sub New( avgType As AverageType )
Me.AvgType = avgType
End Sub
' This method returns a reference to the containing object
' if an object of AverageInfo type is requested.
Public Function GetFormat( argType As Type ) As Object _
Implements IFormatProvider.GetFormat
If argType Is GetType( AverageInfo ) Then
Return Me
Else
Return Nothing
End If
End Function
' Use this property to set or get the type of averaging.
Public Property TypeOfAverage( ) As AverageType
Get
Return Me.AvgType
End Get
Set( ByVal value as AverageType )
Me.AvgType = value
End Set
End Property
End Class
' This class encapsulates an array of Double values and implements
' the IConvertible interface. Most of the IConvertible methods
' return an average of the array elements in one of three types:
' arithmetic mean, geometric mean, or median.
Public Class DataSet
Implements IConvertible
Protected data As ArrayList
Protected defaultProvider As AverageInfo
' Construct the object and add an initial list of values.
' Create a default format provider.
Public Sub New( ParamArray values( ) As Double )
data = New ArrayList( values )
defaultProvider = New AverageInfo( _
AverageType.ArithmeticMean )
End Sub
' Add additional values with this method.
Public Function Add( value As Double ) As Integer
data.Add( value )
Return data.Count
End Function
' Get, set, and add values with this indexer property.
Default Public Property Item(index As Integer) As Double
Get
If index >= 0 AndAlso index < data.Count Then
Return System.Convert.ToDouble( data( index ) )
Else
Throw New InvalidOperationException( _
"[DataSet.get] Index out of range." )
End If
End Get
Set
If index >= 0 AndAlso index < data.Count Then
data( index ) = value
ElseIf index = data.Count Then
data.Add( value )
Else
Throw New InvalidOperationException( _
"[DataSet.set] Index out of range." )
End If
End Set
End Property
' This property returns the number of elements in the object.
Public ReadOnly Property Count( ) As Integer
Get
Return data.Count
End Get
End Property
' This method calculates the average of the object's elements.
Protected Function Average( ByVal avgType As AverageType ) As Double
Dim SumProd As Double
Dim Index As Integer
If data.Count = 0 Then Return 0.0
Select Case avgType
Case AverageType.GeometricMean
SumProd = 1.0
For Index = 0 To data.Count - 1
SumProd *= data( Index )
Next Index
' This calculation will not fail with negative
' elements.
Return Math.Sign( SumProd ) * Math.Pow( _
Math.Abs( SumProd ), 1.0 / data.Count )
Case AverageType.ArithmeticMean
SumProd = 0.0
For Index = 0 To data.Count - 1
SumProd += data( Index )
Next Index
Return SumProd / data.Count
Case AverageType.Median
If data.Count Mod 2 = 0 Then
Return ( data( data.Count \ 2 ) + _
data( data.Count \ 2 - 1 ) ) / 2.0
Else
Return data( data.Count \ 2 )
End If
End Select
End Function
' Get the AverageInfo object from the caller's format
' provider, or use the local default.
Protected Function GetAverageInfo( _
provider As IFormatProvider ) As AverageInfo
Dim avgInfo As AverageInfo = Nothing
If Not provider Is Nothing Then
avgInfo = provider.GetFormat( GetType( AverageInfo ) )
End If
Return IIf( avgInfo Is Nothing, defaultProvider, avgInfo )
End Function
' Calculate the average and limit the range.
Protected Function CalcNLimitAverage( min As Double, _
max As Double, provider as IFormatProvider ) As Double
' Get the format provider and calculate the average.
Dim avgInfo As AverageInfo = GetAverageInfo( provider )
Dim avg As Double = Average( avgInfo.TypeOfAverage )
' Limit the range, based on the minimum and maximum values
' for the type.
Return IIf( avg > max, max, IIf( avg < min, min, avg ) )
End Function
' The following elements are required by IConvertible.
' None of these conversion functions throw exceptions. When
' the data is out of range for the type, the appropriate
' MinValue or MaxValue is used.
Public Function GetTypeCode( ) As TypeCode _
Implements IConvertible.GetTypeCode
Return TypeCode.Object
End Function
Function ToBoolean( ByVal provider As IFormatProvider ) As _
Boolean Implements IConvertible.ToBoolean
' ToBoolean is false if the dataset is empty.
If data.Count <= 0 Then
Return False
' For median averaging, ToBoolean is true if any
' non-discarded elements are nonzero.
ElseIf AverageType.Median = _
GetAverageInfo( provider ).TypeOfAverage Then
If data.Count Mod 2 = 0 Then
Return ( data( data.Count \ 2 ) <> 0.0 Or _
data( data.Count \ 2 - 1 ) <> 0.0 )
Else
Return data( data.Count \ 2 ) <> 0.0
End If
' For arithmetic or geometric mean averaging, ToBoolean is
' true if any element of the dataset is nonzero.
Else
Dim Index As Integer
For Index = 0 To data.Count - 1
If data( Index ) <> 0.0 Then Return True
Next Index
Return False
End If
End Function
Function ToByte( ByVal provider As IFormatProvider ) As Byte _
Implements IConvertible.ToByte
Return Convert.ToByte( CalcNLimitAverage( _
Byte.MinValue, Byte.MaxValue, provider ) )
End Function
Function ToChar( ByVal provider As IFormatProvider ) As Char _
Implements IConvertible.ToChar
Return Convert.ToChar( Convert.ToUInt16( _
CalcNLimitAverage( 0.0, &HFFFF, provider ) ) )
End Function
' Convert to DateTime by adding the calculated average as
' seconds to the current date and time. A valid DateTime is
' always returned.
Function ToDateTime( ByVal provider As IFormatProvider ) As _
DateTime Implements IConvertible.ToDateTime
Dim seconds As Double = Average( _
GetAverageInfo( provider ).TypeOfAverage )
Try
Return DateTime.Now.AddSeconds( seconds )
Catch ex As ArgumentOutOfRangeException
Return IIf( seconds < 0.0, DateTime.MinValue, _
DateTime.MaxValue )
End Try
End Function
Function ToDecimal( ByVal provider As IFormatProvider ) As _
Decimal Implements IConvertible.ToDecimal
' The Double conversion rounds Decimal.MinValue and
' Decimal.MaxValue to invalid Decimal values, so the
' following limits must be used.
Return Convert.ToDecimal( CalcNLimitAverage( _
-79228162514264330000000000000.0, _
79228162514264330000000000000.0, provider ) )
End Function
Function ToDouble( ByVal provider As IFormatProvider) As _
Double Implements IConvertible.ToDouble
Return Average( GetAverageInfo( provider ).TypeOfAverage )
End Function
Function ToInt16( ByVal provider As IFormatProvider ) As _
Short Implements IConvertible.ToInt16
Return Convert.ToInt16( CalcNLimitAverage( _
Int16.MinValue, Int16.MaxValue, provider ) )
End Function
Function ToInt32( ByVal provider As IFormatProvider ) As _
Integer Implements IConvertible.ToInt32
Return Convert.ToInt32( CalcNLimitAverage( _
Int32.MinValue, Int32.MaxValue, provider ) )
End Function
Function ToInt64( ByVal provider As IFormatProvider ) As Long _
Implements IConvertible.ToInt64
' The Double conversion rounds Int64.MinValue and
' Int64.MaxValue to invalid Long values, so the following
' limits must be used.
Return Convert.ToInt64( CalcNLimitAverage( _
-9223372036854775000, 9223372036854775000, provider ) )
End Function
Function ToSByte( ByVal provider As IFormatProvider ) As _
SByte Implements IConvertible.ToSByte
' SByte.MinValue and SByte.MaxValue are not defined in
' Visual Basic.
Return Convert.ToSByte( CalcNLimitAverage( _
-128, 127, provider ) )
End Function
Function ToSingle( ByVal provider As IFormatProvider ) As _
Single Implements IConvertible.ToSingle
Return Convert.ToSingle( CalcNLimitAverage( _
Single.MinValue, Single.MaxValue, provider ) )
End Function
Function ToUInt16( ByVal provider As IFormatProvider ) As _
UInt16 Implements IConvertible.ToUInt16
' UInt16.MinValue and UInt16.MaxValue are not defined in
' Visual Basic.
Return Convert.ToUInt16( CalcNLimitAverage( _
0, &HFFFF, provider ) )
End Function
Function ToUInt32( ByVal provider As IFormatProvider ) As _
UInt32 Implements IConvertible.ToUInt32
' UInt32.MinValue and UInt32.MaxValue are not defined in
' Visual Basic.
Return Convert.ToUInt32( CalcNLimitAverage( _
0, 4294967295, provider ) )
End Function
Function ToUInt64( ByVal provider As IFormatProvider ) As _
UInt64 Implements IConvertible.ToUInt64
' UInt64.MinValue and UInt64.MaxValue are not defined in
' Visual Basic. The Double conversion would have rounded
' UInt64.MaxValue, so the following limit must be used.
Return Convert.ToUInt64( CalcNLimitAverage( _
0, 18446744073709550000.0, provider ) )
End Function
Function ToType( ByVal conversionType As Type, _
ByVal provider As IFormatProvider) As Object _
Implements IConvertible.ToType
Return Convert.ChangeType( Average( GetAverageInfo( _
provider ).TypeOfAverage ), conversionType )
End Function
Overloads Function ToString( ByVal provider As IFormatProvider _
) As String Implements IConvertible.ToString
Dim avgType as AverageType = _
GetAverageInfo( provider ).TypeOfAverage
Return String.Format( "( {0}: {1:G10} )", avgType, _
Average( avgType ) )
End Function
End Class
' Display a DataSet with three different format providers.
Sub DisplayDataSet( ds As DataSet )
Dim fmt As String = "{0,-12}{1,20}{2,20}{3,20}"
Dim median As AverageInfo = New AverageInfo( AverageType.Median )
Dim geMean As AverageInfo = _
New AverageInfo( AverageType.GeometricMean )
Dim iX As Integer
' Display the dataset elements.
If ds.Count > 0 Then
Console.Write( vbCrLf & "DataSet: [{0}", ds( 0 ) )
For iX = 1 To ds.Count - 1
Console.Write( ", {0}", ds( iX ) )
Next iX
Console.WriteLine( "]" & vbCrLf )
End If
Console.WriteLine( fmt, "Convert.", "Default", _
"Geometric Mean", "Median" )
Console.WriteLine( fmt, "--------", "-------", _
"--------------", "------" )
Console.WriteLine( fmt, "ToBoolean", _
Convert.ToBoolean( ds, Nothing ), _
Convert.ToBoolean( ds, geMean ), _
Convert.ToBoolean( ds, median ) )
Console.WriteLine( fmt, "ToByte", _
Convert.ToByte( ds, Nothing ), _
Convert.ToByte( ds, geMean ), _
Convert.ToByte( ds, median ) )
Console.WriteLine( fmt, "ToChar", _
Convert.ToChar( ds, Nothing ), _
Convert.ToChar( ds, geMean ), _
Convert.ToChar( ds, median ) )
Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" & _
"{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", _
"ToDateTime", Convert.ToDateTime( ds, Nothing ), _
Convert.ToDateTime( ds, geMean ), _
Convert.ToDateTime( ds, median ) )
Console.WriteLine( fmt, "ToDecimal", _
Convert.ToDecimal( ds, Nothing ), _
Convert.ToDecimal( ds, geMean ), _
Convert.ToDecimal( ds, median ) )
Console.WriteLine( fmt, "ToDouble", _
Convert.ToDouble( ds, Nothing ), _
Convert.ToDouble( ds, geMean ), _
Convert.ToDouble( ds, median ) )
Console.WriteLine( fmt, "ToInt16", _
Convert.ToInt16( ds, Nothing ), _
Convert.ToInt16( ds, geMean ), _
Convert.ToInt16( ds, median ) )
Console.WriteLine( fmt, "ToInt32", _
Convert.ToInt32( ds, Nothing ), _
Convert.ToInt32( ds, geMean ), _
Convert.ToInt32( ds, median ) )
Console.WriteLine( fmt, "ToInt64", _
Convert.ToInt64( ds, Nothing ), _
Convert.ToInt64( ds, geMean ), _
Convert.ToInt64( ds, median ) )
Console.WriteLine( fmt, "ToSByte", _
Convert.ToSByte( ds, Nothing ), _
Convert.ToSByte( ds, geMean ), _
Convert.ToSByte( ds, median ) )
Console.WriteLine( fmt, "ToSingle", _
Convert.ToSingle( ds, Nothing ), _
Convert.ToSingle( ds, geMean ), _
Convert.ToSingle( ds, median ) )
Console.WriteLine( fmt, "ToUInt16", _
Convert.ToUInt16( ds, Nothing ), _
Convert.ToUInt16( ds, geMean ), _
Convert.ToUInt16( ds, median ) )
Console.WriteLine( fmt, "ToUInt32", _
Convert.ToUInt32( ds, Nothing ), _
Convert.ToUInt32( ds, geMean ), _
Convert.ToUInt32( ds, median ) )
Console.WriteLine( fmt, "ToUInt64", _
Convert.ToUInt64( ds, Nothing ), _
Convert.ToUInt64( ds, geMean ), _
Convert.ToUInt64( ds, median ) )
End Sub
Sub Main( )
Console.WriteLine( _
"This example of the Convert.To<Type>( Object, " & _
"IFormatProvider ) methods " & vbCrLf & "generates " & _
"the following output. The example displays the " & _
"values " & vbCrLf & "returned by the methods, " & _
"using several IFormatProvider objects." & vbCrLf )
Dim ds1 As New DataSet( 10.5, 22.2, 45.9, 88.7, 156.05, 297.6 )
DisplayDataSet( ds1 )
Dim ds2 As New DataSet( _
359999.95, 425000, 499999.5, 775000, 1695000 )
DisplayDataSet( ds2 )
End Sub
End Module
' This example of the Convert.To<Type>( Object, IFormatProvider ) methods
' generates the following output. The example displays the values
' returned by the methods, using several IFormatProvider objects.
'
' DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
'
' Convert. Default Geometric Mean Median
' -------- ------- -------------- ------
' ToBoolean True True True
' ToByte 103 59 67
' ToChar g ; C
' ToDateTime 2003-05-13 14:52:53 2003-05-13 14:52:09 2003-05-13 14:52:17
' ToDecimal 103.491666666667 59.4332135445164 67.3
' ToDouble 103.491666666667 59.4332135445164 67.3
' ToInt16 103 59 67
' ToInt32 103 59 67
' ToInt64 103 59 67
' ToSByte 103 59 67
' ToSingle 103.4917 59.43321 67.3
' ToUInt16 103 59 67
' ToUInt32 103 59 67
' ToUInt64 103 59 67
'
' DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
'
' Convert. Default Geometric Mean Median
' -------- ------- -------------- ------
' ToBoolean True True True
' ToByte 255 255 255
' ToChar ? ? ?
' ToDateTime 2003-05-22 07:27:49 2003-05-20 22:17:27 2003-05-19 09:44:29
' ToDecimal 750999.89 631577.237188435 499999.5
' ToDouble 750999.89 631577.237188435 499999.5
' ToInt16 32767 32767 32767
' ToInt32 751000 631577 500000
' ToInt64 751000 631577 500000
' ToSByte 127 127 127
' ToSingle 750999.9 631577.3 499999.5
' ToUInt16 65535 65535 65535
' ToUInt32 751000 631577 500000
' ToUInt64 751000 631577 500000
作者：VB.NET开发
项目：Syste
Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As Long
For Each number As ULong In numbers
Try
result = Convert.ToInt64(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.", _
number.GetType().Name, number)
End Try
Next
作者：VB.NET开发
项目：Syste
Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As Long
For Each number As UInteger In numbers
result = Convert.ToInt64(number)
Console.WriteLine("Converted the {0} value {1:N0} to the {2} value {3:N0}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Next
作者：VB.NET开发
项目：Syste
Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As Long
For Each number As UShort In numbers
Try
result = Convert.ToInt64(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.", _
number.GetType().Name, number)
End Try
Next
作者：VB.NET开发
项目：Syste
Dim values() As String = { "One", "1.34e28", "-26.87", "-18", "-6.00", _
" 0", "137", "1601.9", Int32.MaxValue.ToString() }
Dim result As Long
For Each value As String In values
Try
result = Convert.ToInt64(value)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
value.GetType().Name, value, result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int64 type.", value)
Catch e As FormatException
Console.WriteLine("The {0} value '{1}' is not in a recognizable format.", _
value.GetType().Name, value)
End Try
Next
作者：VB.NET开发
项目：Syste
Dim numbers() As SByte = { SByte.MinValue, -1, 0, 10, SByte.MaxValue }
Dim result As Long
For Each number As SByte In numbers
result = Convert.ToInt64(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Next
作者：VB.NET开发
项目：Syste
Dim values() As Object = { True, -12, 163, 935, "x"c, #5/12/2009#, _
"104", "103.0", "-1", _
"1.00e2", "One", 1.00e2, 16.3e42}
Dim result As Long
For Each value As Object In values
Try
result = Convert.ToInt64(value)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
value.GetType().Name, value, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.", _
value.GetType().Name, value)
Catch e As FormatException
Console.WriteLine("The {0} value {1} is not in a recognizable format.", _
value.GetType().Name, value)
Catch e As InvalidCastException
Console.WriteLine("No conversion to an Int64 exists for the {0} value {1}.", _
value.GetType().Name, value)
End Try
Next
作者：VB.NET开发
项目：Syste
Dim numbers() As Integer = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue }
Dim result As Long
For Each number As Integer In numbers
result = Convert.ToInt64(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Next
作者：VB.NET开发
项目：Syste
Dim bytes() As Byte = { Byte.MinValue, 14, 122, Byte.MaxValue}
Dim result As Long
For Each byteValue As Byte In bytes
result = Convert.ToInt64(byteValue)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
byteValue.GetType().Name, byteValue, _
result.GetType().Name, result)
Next
作者：VB.NET开发
项目：Syste
Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(1023), _
ChrW(Short.MaxValue), ChrW(&hFFFE) }
Dim result As Long
For Each ch As Char in chars
result = Convert.ToInt64(ch)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
ch.GetType().Name, ch, _
result.GetType().Name, result)
Next
作者：VB.NET开发
项目：Syste
Dim falseFlag As Boolean = False
Dim trueFlag As Boolean = True
Console.WriteLine("{0} converts to {1}.", falseFlag, _
Convert.ToInt64(falseFlag))
Console.WriteLine("{0} converts to {1}.", trueFlag, _
Convert.ToInt64(trueFlag))
作者：VB.NET开发
项目：Syste
Dim values() As Double = { Double.MinValue, -1.38e10, -1023.299, -12.98, _
0, 9.113e-16, 103.919, 17834.191, Double.MaxValue }
Dim result As Long
For Each value As Double In values
Try
result = Convert.ToInt64(value)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
value.GetType().Name, value, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int64 type.", value)
End Try
Next
' -1.79769313486232E+308 is outside the range of the Int64 type.
' -13800000000 is outside the range of the Int16 type.
' Converted the Double value '-1023.299' to the Int64 value -1023.
' Converted the Double value '-12.98' to the Int64 value -13.
' Converted the Double value '0' to the Int64 value 0.
' Converted the Double value '9.113E-16' to the Int64 value 0.
' Converted the Double value '103.919' to the Int64 value 104.
' Converted the Double value '17834.191' to the Int64 value 17834.
' 1.79769313486232E+308 is outside the range of the Int64 type.
作者：VB.NET开发
项目：Syste
Dim numbers() As Short = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue }
Dim result As Long
For Each number As Short In numbers
result = Convert.ToInt64(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Next
作者：VB.NET开发
项目：Syste
Dim values() As Decimal = { Decimal.MinValue, -1034.23d, -12d, 0d, 147d, _
199.55d, 9214.16d, Decimal.MaxValue }
Dim result As Long
For Each value As Decimal In values
Try
result = Convert.ToInt64(value)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
value.GetType().Name, value, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int64 type.", _
value)
End Try
Next
作者：VB程序
项目：Syste
' 导入命名空间
Imports System
Public Class MainClass
Shared Sub Main( )
Dim l As Long
Dim s As Single
l = Long.MaxValue
Console.WriteLine(l)
s = Convert.ToSingle(l)
s -= 1000000000000
l = Convert.ToInt64(s)
Console.WriteLine(l)
End Sub 'Main
End Class
