IntPtr to Uint32? C#

Question

Hello,

I need to call VirtualAllocEx and it returns IntPtr. I call that function to get an empty address so I can write my codecave there(this is in another process).

How do I convert the result into UInt32,so I could call WriteProcessMemory() lately with that address?

Answer 1

When you call WriteProcessMemory, you should be passing an IntPtr for the address rather than a UInt32 (because WriteProcessMemory expects a pointer, not an integer). So you should be able to use the IntPtr returned by VirtualAllocEx directly without the need to convert it to a UInt32.

Answer 2

You could just cast it with (uint)ptr I believe (If it won't cast nicely, try ptr.ToInt32() or ToInt64() first. At least I don't know of any issues with this approach, haven't used it -that- much though. Given UInt32 has larger range than Int32 and same as Int64 on non-negative side it should be good enough.

Although not sure how the Int32 behaves on 64 bit architectures. Badly I'd imagine as the reason for IntPtr is to provide platform independant way to store pointers.

Answer 3

Your DLlImport for WriteProcessMemory is incorrect, base address is a pointer so it should be defined as IntPtr.

MSDN

You need to fix your DllImport statement.