Kernel32VirtualAllocEx(IntPtr, IntPtr, IntPtr, MemoryAllocationType, MemoryProtectionOptions) Method

[DllImportAttribute("Kernel32.dll", ExactSpelling = true, SetLastError = true)]
public static IntPtr VirtualAllocEx(
	IntPtr hProcess,
	IntPtr address,
	IntPtr size,
	MemoryAllocationType allocationType,
	MemoryProtectionOptions protection
)

<DllImportAttribute("Kernel32.dll", ExactSpelling := true, SetLastError := true>]
Public Shared Function VirtualAllocEx ( 
	hProcess As IntPtr,
	address As IntPtr,
	size As IntPtr,
	allocationType As MemoryAllocationType,
	protection As MemoryProtectionOptions
) As IntPtr

Dim hProcess As IntPtr
Dim address As IntPtr
Dim size As IntPtr
Dim allocationType As MemoryAllocationType
Dim protection As MemoryProtectionOptions

Dim returnValue As IntPtr

returnValue = Kernel32.VirtualAllocEx(hProcess, 
	address, size, allocationType, protection)

public:
[DllImportAttribute(L"Kernel32.dll", ExactSpelling = true, SetLastError = true)]
static IntPtr VirtualAllocEx(
	[InAttribute] IntPtr hProcess, 
	[InAttribute] IntPtr address, 
	IntPtr size, 
	MemoryAllocationType allocationType, 
	MemoryProtectionOptions protection
)

[<DllImportAttribute("Kernel32.dll", ExactSpelling = true, SetLastError = true)>]
static member VirtualAllocEx : 
        hProcess : IntPtr * 
        address : IntPtr * 
        size : IntPtr * 
        allocationType : MemoryAllocationType * 
        protection : MemoryProtectionOptions -> IntPtr 

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

Parameters

hProcess  IntPtr

The handle to a process.

The function allocates memory within the virtual address space of this process.

The handle must have the VirtualMemoryOperation access right

address  IntPtr

The pointer that specifies a desired starting address for the region of pages that you want to allocate.

If you are reserving memory, the function rounds this address down to the nearest multiple of the allocation granularity.

If you are committing memory that is already reserved, the function rounds this address down to the nearest page boundary.

To determine the size of a page and the allocation granularity on the host computer, use the GetSystemInfo function.

If address is Zero, the function determines where to allocate the region.

If this address is within an enclave that you have not initialized by calling InitializeEnclave function, VirtualAllocEx(IntPtr, IntPtr, IntPtr, MemoryAllocationType, MemoryProtectionOptions) allocates a page of zeros for the enclave at that address.

The page must be previously uncommitted, and will not be measured with the EEXTEND instruction of the Intel Software Guard Extensions programming model.

If the address in within an enclave that you initialized, then the allocation operation fails with the ERROR_INVALID_ADDRESS error.

size  IntPtr

The size of the region of memory to allocate, in bytes.

If address is Zero, the function rounds size up to the next page boundary.

If address is not Zero, the function allocates all pages that contain one or more bytes in the range from address to address+size. This means, for example, that a 2-byte range that straddles a page boundary causes the function to allocate both pages.

allocationType  MemoryAllocationType

The type of memory allocation.

protection  MemoryProtectionOptions

The memory protection for the region of pages to be allocated.

If address parameter specifies an address within an enclave, protection cannot be any of the following values:

NoAccess, Guard, NoCache, WriteCombine

Return Value

If the function fails, the return value is Zero.

To get extended error information, call GetLastWin32Error.

Reference