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WriteProcessMemory (kernel32)

C# Signature:

static extern bool WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress,
   byte [] lpBuffer, uint nSize, out int lpNumberOfBytesWritten);

VB.Net Signature:

<DllImport("kernel32.dll")> _
Public Shared Function WriteProcessMemory(ByVal hProcess As IntPtr, ByVal lpBaseAddress As IntPtr, ByVal lpBuffer As Byte(), ByVal nSize As UInt, <Out()> ByRef lpNumberOfBytesWritten As Int) As Boolean
End Function

User-Defined Types:




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;

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 ( provides a ProcessMemoryChunk class to allocate and access memory of a different process.


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