Convert.ToUInt64 Method (Object, IFormatProvider)


Converts the value of the specified object to a 64-bit unsigned integer, using the specified culture-specific formatting information.

This API is not CLS-compliant.

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

static member ToUInt64 : 
        value:Object *
        provider:IFormatProvider -> uint64


Type: System.Object

An object that implements the IConvertible interface.

Type: System.IFormatProvider

An object that supplies culture-specific formatting information.

Return Value

Type: System.UInt64

A 64-bit unsigned integer that is equivalent to value, or zero if value is null.

Exception Condition

value is not in an appropriate format.


value does not implement the IConvertible interface.


The conversion is not supported.


value represents a number that is less than UInt64.MinValue or greater than UInt64.MaxValue.

The return value is the result of invoking the IConvertible.ToUInt64 method of the underlying type of value.

provider enables the user to specify culture-specific conversion information about the contents of value. For example, if value is a String that represents a number, provider could supply culture-specific information about the notation used to represent that number.

The base types ignore provider; however, the parameter may be used if value is a user-defined type that implements the IConvertible interface.

The following example defines a HexString class that implements the IConvertible interface and that is designed to hold the string representation of both 64-bit signed and 64-bit unsigned values. The class includes a Sign property that indicates the sign of its hexadecimal value.

No code example is currently available or this language may not be supported.

The following example shows that a call to the ToUInt64(Object, IFormatProvider) method that passes a HexString object as a parameter, in turn, calls the IConvertible.ToUInt64 implementation of the HexString class.

No code example is currently available or this language may not be supported.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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