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Convert.ToInt64 Method (Double)

Converts the value of the specified double-precision floating-point number to an equivalent 64-bit signed integer.

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

public static long ToInt64(
	double value
)

Parameters

value
Type: System.Double

The double-precision floating-point number to convert.

Return Value

Type: System.Int64
value, rounded to the nearest 64-bit signed integer. If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

ExceptionCondition
OverflowException

value is greater than Int64.MaxValue or less than Int64.MinValue.

The following example attempts to convert each element in an array of Double values to a long integer.

double[] values= { Double.MinValue, -1.38e10, -1023.299, -12.98,
                   0, 9.113e-16, 103.919, 17834.191, Double.MaxValue };
long result;

foreach (double value 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 (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int64 type.", value);
   }   
}                                 
//    -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.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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