Kernel32VirtualProtect(IntPtr, UIntPtr, MemoryProtectionOptions, MemoryProtectionOptions) Method

[DllImportAttribute("Kernel32.dll", SetLastError = true)]
public static bool VirtualProtect(
	IntPtr address,
	UIntPtr size,
	MemoryProtectionOptions newProtect,
	out MemoryProtectionOptions refOldProtect
)

<DllImportAttribute("Kernel32.dll", SetLastError := true>]
Public Shared Function VirtualProtect ( 
	address As IntPtr,
	size As UIntPtr,
	newProtect As MemoryProtectionOptions,
	<OutAttribute> ByRef refOldProtect As MemoryProtectionOptions
) As Boolean

Dim address As IntPtr
Dim size As UIntPtr
Dim newProtect As MemoryProtectionOptions
Dim refOldProtect As MemoryProtectionOptions

Dim returnValue As Boolean

returnValue = Kernel32.VirtualProtect(address, 
	size, newProtect, refOldProtect)

public:
[DllImportAttribute(L"Kernel32.dll", SetLastError = true)]
static bool VirtualProtect(
	[InAttribute] IntPtr address, 
	UIntPtr size, 
	MemoryProtectionOptions newProtect, 
	[OutAttribute] MemoryProtectionOptions% refOldProtect
)

[<DllImportAttribute("Kernel32.dll", SetLastError = true)>]
static member VirtualProtect : 
        address : IntPtr * 
        size : UIntPtr * 
        newProtect : MemoryProtectionOptions * 
        refOldProtect : MemoryProtectionOptions byref -> bool 

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

Parameters

address  IntPtr

A pointer an address that describes the starting page of the region of pages whose access protection attributes are to be changed.

All pages in the specified region must be within the same reserved region allocated when calling the VirtualAlloc(IntPtr, IntPtr, MemoryAllocationType, MemoryProtectionOptions) or VirtualAllocEx(IntPtr, IntPtr, IntPtr, MemoryAllocationType, MemoryProtectionOptions) function using Reserve flag.

The pages cannot span adjacent reserved regions that were allocated by separate calls to VirtualAlloc(IntPtr, IntPtr, MemoryAllocationType, MemoryProtectionOptions) or VirtualAllocEx(IntPtr, IntPtr, IntPtr, MemoryAllocationType, MemoryProtectionOptions) function using Reserve flag.

size  UIntPtr

The size of the region whose access protection attributes are to be changed, in bytes.

The region of affected pages includes all pages containing one or more bytes in the range from the address parameter to (address+size).

This means that a 2-byte range straddling a page boundary causes the protection attributes of both pages to be changed.

newProtect  MemoryProtectionOptions

The memory protection option.

refOldProtect  MemoryProtectionOptions

A pointer to a variable that receives the previous memory protection option value of the first page in the specified region of pages.

If this parameter is or does not point to a valid variable, the function fails.

Return Value

If the function fails, the return value is .

To get extended error information, call GetLastWin32Error.

Reference