C# Signature:

[DllImport("kernel32.dll")]
static extern IntPtr OpenProcess(ProcessAccessFlags dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle,
   uint dwProcessId);

VB.NET Signature:

  Declare Auto Function OpenProcess Lib "kernel32.dll" (ByVal dwDesiredAccess As PROCESS_ACCESS, ByVal bInheritHandle As Boolean, ByVal dwProcessId As Long) As IntPtr
  End Function

User-Defined Types (VB.NET):

    <Flags()> _
    Public Enum PROCESS_ACCESS As Long
    ' Specifies all possible access flags for the process object.
    PROCESS_ALL_ACCESS = &H1F0FFF

    ' Enables using the process handle in the CreateRemoteThread function
    ' to create a thread in the process.
    PROCESS_CREATE_THREAD = &H2

    ' Enables using the process handle as either the source or
    ' target process in the DuplicateHandle function to duplicate a handle.
    PROCESS_DUP_HANDLE = &H40

    ' Enables using the process handle in the GetExitCodeProcess and
    ' GetPriorityClass functions to read information from the process object.
    PROCESS_QUERY_INFORMATION = &H400

    ' Enables using the process handle in the SetPriorityClass function to
    ' set the priority class of the process.
    PROCESS_SET_INFORMATION = &H200

    ' Enables using the process handle in the TerminateProcess function to
    ' terminate the process.
    PROCESS_TERMINATE = &H1

    ' Enables using the process handle in the VirtualProtectEx and
    ' WriteProcessMemory functions to modify the virtual memory of the process.
    PROCESS_VM_OPERATION = &H8

    ' Enables using the process handle in the ReadProcessMemory function to
    ' read from the virtual memory of the process.
    PROCESS_VM_READ = &H10

    ' Enables using the process handle in the WriteProcessMemory function to
    ' write to the virtual memory of the process.
    PROCESS_VM_WRITE = &H20

    ' Enables using the process handle in any of the wait functions to wait
    ' for the process to terminate.
    SYNCHRONIZE = &H100000
    End Enum

User-Defined Types (C#):

    [Flags]
    public enum ProcessAccessFlags : uint
    {
        All = 0x001F0FFF,
        Terminate = 0x00000001,
        CreateThread = 0x00000002,
        VMOperation = 0x00000008,
        VMRead = 0x00000010,
        VMWrite = 0x00000020,
        DupHandle = 0x00000040,
        SetInformation = 0x00000200,
        QueryInformation = 0x00000400,
        Synchronize = 0x00100000
    }

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

        ' Get the handle of a running process
        Dim curProcess As Process = Process.GetCurrentProcess()
        hProcess = OpenProcess(PROCESS_ACCESS.PROCESS_QUERY_INFORMATION, True, curProcess.Id)

C#

    //a Variable to hold the process id
    uint ProccessID;

    //Gets the Handle To the Window (Using an Open Notepad Window For Example)

    IntPtr hWnd = FindWindow(0, "Untitled - Notepad");

    // Gets The Windows Process ID To Use later
    GetWindowThreadProcessId(hWnd, out ProccessID);

    //Opens the Process
    IntPtr ProcessHandle = OpenProcess(ProcessAccessFlags.VMRead, false, ProccessID);

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