C# Signature:
[DllImport("kernel32.dll", SetLastError=true, ExactSpelling=true)]
static extern IntPtr VirtualAllocEx(IntPtr hProcess, IntPtr lpAddress,
IntPtr dwSize, AllocationType flAllocationType, MemoryProtection flProtect);
C# Signature:
[DllImport("kernel32")]
public static extern IntPtr VirtualAlloc(IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);
C# Signature:
[DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
static extern IntPtr VirtualAllocEx(IntPtr hProcess,
IntPtr lpAddress,
int dwSize,
AllocationType flAllocationType,
MemoryProtection flProtect);
VB.NET Signature:
<DllImport("kernel32.dll", SetLastError:=True, ExactSpelling:=True)> _
Private Function VirtualAllocEx(ByVal hProcess As IntPtr, ByVal lpAddress As IntPtr, _
ByVal dwSize As IntPtr, ByVal flAllocationType As UInteger, _
ByVal flProtect As UInteger) As IntPtr
End Function
VBA Signature:
Private Declare PtrSafe Function VirtualAlloc Lib "KERNEL32.dll" _
(ByVal lpAddress As LongPtr, ByVal dwSize As LongPtr, ByVal flAllocationType As Long, ByVal flProtect As Long) As LongPtr
Boo Signature:
[DllImport("kernel32.dll")]
def VirtualAllocEx(hProcess as IntPtr, lpAddress as IntPtr, dwSize as UInt32, flNewProtect as UInt32, lpflOldProtect as UInt32) as IntPtr:
pass
User-Defined Types:
[Flags]
public enum AllocationType
{
Commit = 0x1000,
Reserve = 0x2000,
Decommit = 0x4000,
Release = 0x8000,
Reset = 0x80000,
Physical = 0x400000,
TopDown = 0x100000,
WriteWatch = 0x200000,
LargePages = 0x20000000
}
[Flags]
public enum MemoryProtection
{
Execute = 0x10,
ExecuteRead = 0x20,
ExecuteReadWrite = 0x40,
ExecuteWriteCopy = 0x80,
NoAccess = 0x01,
ReadOnly = 0x02,
ReadWrite = 0x04,
WriteCopy = 0x08,
GuardModifierflag = 0x100,
NoCacheModifierflag = 0x200,
WriteCombineModifierflag = 0x400
}
Notes:
None.
Tips & Tricks:
You can get the dwSize in C# with sizeof(TYPE) for blittable types or Marshal.SizeOf(typeof(TYPE)) for non-blittable types
Sample Code:
IntPtr allocatedBaseAddress = VirtualAllocEx(process.Handle, IntPtr.Zero, buffer.Length, AllocationType.Commit | AllocationType.Reserve, MemoryProtection.ExecuteReadWrite);
Alternative Managed API:
The ManagedWindowsApi project (http://mwinapi.sourceforge.net) provides a ProcessMemoryChunk class to allocate and access memory of a different process.
