C# Signature:

[DllImport("kernel32.dll",SetLastError = true)]
static extern bool WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, byte [] lpBuffer, uint nSize, out UIntPtr lpNumberOfBytesWritten);

VB.Net Signature:

<DllImport("kernel32.dll", SetLastError:=True)> _
Public Shared Function WriteProcessMemory(ByVal hProcess As IntPtr, ByVal lpBaseAddress As IntPtr, ByVal lpBuffer As Byte(), ByVal nSize As System.UInt32, <Out()> ByRef lpNumberOfBytesWritten As IntPtr) As Boolean
End Function

Boo Signature:

[DllImport("kernel32.dll", SetLastError : true)]
protected static def WriteProcessMemory(hProcess as IntPtr, lpBaseAddress as IntPtr, lpBuffer as (byte), nSize as int, ref lpNumberOfBytesWritten as int) as bool:
     pass

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

public int WriteByteArray( IntPtr BaseAddress, byte [] NewVal )
{
    // Return Value
    int ReturnVal;

    // Write Memory Byte Array
    ReturnVal = WriteProcessMemory( this.hProcess, BaseAddress, NewVal, NewVal.Length, out this.BytesWritten );

    return this.BytesWritten;
}

'VB.Net
Public Shared Function Poke(ByVal proc As Process, ByVal target As Integer, ByVal data As Byte()) As Boolean
    Return WriteProcessMemory(proc.Handle, New IntPtr(target), data, data.Length, 0)
End Function

Alternative Managed API:

The ManagedWindowsApi project (http://mwinapi.sourceforge.net) provides a ProcessMemoryChunk class to allocate and access memory of a different process.