Convert.ToInt64 Method (String)

Converts the specified String representation of a number to an equivalent 64-bit signed integer.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Shared Function ToInt64 ( _
	value As String _
) As Long

Parameters

value
Type: System.String
A String containing a number to convert.

Return Value

Type: System.Int64
A 64-bit signed integer equivalent to the value of value.
-or-
Zero if value is Nothing.

ExceptionCondition
FormatException

value does not consist of an optional sign followed by a sequence of digits (zero through nine).

OverflowException

value represents a number less than MinValue or greater than MaxValue.

The return value is the result of invoking the Int64.Parse method on value.

If you prefer not to handle an exception if the conversion fails, you can call the Int64.TryParse method instead. It returns a Boolean value that indicates whether the conversion succeeded or failed.

The following code example converts String representations of 64-bit integers with the ToInt64 method, using default formatting.


' Example of the Convert.ToInt64( String ) and 
' Convert.ToInt64( String, IFormatProvider ) methods.
Imports System.Globalization

Module Example

   Dim format As String = "{0,-22}{1,-20}{2}"

   ' Get the exception type name; remove the namespace prefix.
   Function GetExceptionType(ByVal ex As Exception) As String

      Dim exceptionType As String = ex.GetType().ToString()
      Return exceptionType.Substring( _
          exceptionType.LastIndexOf("."c) + 1)
   End Function

   Sub ConvertToInt64(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal numericStr As String, _
       ByVal provider As IFormatProvider)

      Dim defaultValue As Object
      Dim providerValue As Object

      ' Convert numericStr to Int64 without a format provider.
      Try
         defaultValue = Convert.ToInt64(numericStr)
      Catch ex As Exception
         defaultValue = GetExceptionType(ex)
      End Try

      ' Convert numericStr to Int64 with a format provider.
      Try
         providerValue = Convert.ToInt64(numericStr, provider)
      Catch ex As Exception
         providerValue = GetExceptionType(ex)
      End Try

      outputBlock.Text &= String.Format(format, numericStr, _
          defaultValue, providerValue) & vbCrLf
   End Sub

   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      ' Create a NumberFormatInfo object and set several of its
      ' properties that apply to numbers.
      Dim provider As NumberFormatInfo = New NumberFormatInfo()

      ' These properties affect the conversion.
      provider.NegativeSign = "neg "
      provider.PositiveSign = "pos "

      ' These properties do not affect the conversion.
      ' The input string cannot have decimal and group separators.
      provider.NumberDecimalSeparator = "."
      provider.NumberGroupSeparator = ","
      provider.NumberGroupSizes = New Integer() {3}
      provider.NumberNegativePattern = 0

      outputBlock.Text &= String.Format("This example of" & vbCrLf & _
          "  Convert.ToInt64( String ) and " & vbCrLf & _
          "  Convert.ToInt64( String, IFormatProvider ) " & _
          vbCrLf & "generates the following output. It " & _
          "converts several strings to " & vbCrLf & "Long " & _
          "values, using default formatting " & _
          "or a NumberFormatInfo object." & vbCrLf) & vbCrLf
      outputBlock.Text &= String.Format(format, "String to convert", _
          "Default/exception", "Provider/exception") & vbCrLf
      outputBlock.Text &= String.Format(format, "-----------------", _
          "-----------------", "------------------") & vbCrLf

      ' Convert strings, with and without an IFormatProvider.
      ConvertToInt64(outputBlock, "123456789", provider)
      ConvertToInt64(outputBlock, "+123456789", provider)
      ConvertToInt64(outputBlock, "pos 123456789", provider)
      ConvertToInt64(outputBlock, "-123456789", provider)
      ConvertToInt64(outputBlock, "neg 123456789", provider)
      ConvertToInt64(outputBlock, "123456789.", provider)
      ConvertToInt64(outputBlock, "123,456,789", provider)
      ConvertToInt64(outputBlock, "(123456789)", provider)
      ConvertToInt64(outputBlock, "9223372036854775808", provider)
      ConvertToInt64(outputBlock, "-9223372036854775809", provider)
   End Sub
End Module

' This example of
'   Convert.ToInt64( String ) and
'   Convert.ToInt64( String, IFormatProvider )
' generates the following output. It converts several strings to
' Long values, using default formatting or a NumberFormatInfo object.
' 
' String to convert     Default/exception   Provider/exception
' -----------------     -----------------   ------------------
' 123456789             123456789           123456789
' +123456789            123456789           FormatException
' pos 123456789         FormatException     123456789
' -123456789            -123456789          FormatException
' neg 123456789         FormatException     -123456789
' 123456789.            FormatException     FormatException
' 123,456,789           FormatException     FormatException
' (123456789)           FormatException     FormatException
' 9223372036854775808   OverflowException   OverflowException
' -9223372036854775809  OverflowException   FormatException


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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