Marshal.ReadInt64 Method (Object, Int32)

Reads a 64-bit signed integer from unmanaged memory.

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

public static long ReadInt64 (
	[InAttribute] Object ptr,
	int ofs
public static long ReadInt64 (
	/** @attribute InAttribute() */ Object ptr, 
	int ofs
public static function ReadInt64 (
	ptr : Object, 
	ofs : int
) : long



The base address in unmanaged memory of the source object.


An additional byte offset, added to the ptr parameter before reading.

Return Value

The 64-bit signed integer read from the ptr parameter.

Exception typeCondition


ptr is not a recognized format.


ptr is a null reference (Nothing in Visual Basic).


ptr is invalid.


ptr is an ArrayWithOffset object. This method does not accept ArrayWithOffset parameters.

ReadInt64 enables direct interaction with an unmanaged 64-bit signed array, eliminating the expense of copying an entire unmanaged array (using Marshal.Copy) to a separate managed array before reading its element values.


This method uses SecurityAction.LinkDemand to prevent it from being called from untrusted code; only the immediate caller is required to have SecurityPermissionAttribute.UnmanagedCode permission. If your code can be called from partially trusted code, do not pass user input to Marshal class methods without validation. For important limitations on using the LinkDemand member, see Demand vs. LinkDemand.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0, 1.1, 1.0

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