using System;
using System.Runtime.InteropServices;

namespace Text
{
    class Program
    {
        [DllImport("kernel32.dll ")]
        public static extern uint OpenProcess(UInt32 dwDesiredAccess, bool bInheritHandle, UInt32 dwProcessId);
        [DllImport("User32.dll ")]
        public static extern System.IntPtr FindWindowEx(System.IntPtr parent, System.IntPtr childe, string strclass, string strname);
        [DllImport("user32.dll")]
        public static extern uint GetWindowThreadProcessId(IntPtr hwnd, out int pid);
        [DllImport("Kernel32")]
        public static extern int GetProcAddress(int handle, String funcname);
        [DllImport("kernel32", EntryPoint = "GetModuleHandle")]
        public static extern int GetModuleHandle(string lpModuleName);
        [DllImport("kernel32", EntryPoint = "WriteProcessMemory")]
        public static extern int WriteProcessMemory(uint hwnd, UInt32 baseaddress, int lpBuffer, int nsize, int filewriten);


        static void Main(string[] args)
        {

            #region 测试
            unsafe
            {
                Console.WriteLine("----------Press Any Key To Start----------");
                Console.ReadKey();

                Console.WriteLine("开始");

                const uint PROCESS_ALL_ACCESS = 0x1F0FFF; //定义权限   
                //const uint PROCESS_VM_READ = 0x0010;
                //const uint PROCESS_VM_WRITE = 0x0020;
                //string winName = "计算器";
                string winName = "无标题 - 记事本";
                IntPtr hwnd = FindWindowEx(System.IntPtr.Zero, System.IntPtr.Zero, null, winName); // 取句柄
                int pid;
                uint dwProcessId = GetWindowThreadProcessId(hwnd, out pid); // 取进程ID
                uint hProcess = OpenProcess(PROCESS_ALL_ACCESS, false, dwProcessId); // 打开进程

                Console.WriteLine("Pid={0}, Hwnd={1},hProcess={2}", pid.ToString(), hwnd, hProcess);

                if (hProcess > 0)
                {
                    UInt16 ModiCode = 0xEB;
                    UInt32 MutexAAdd = (UInt32)GetProcAddress(GetModuleHandle("Kernel32.dll"), "CreateMutexA") + 13;
                    WriteProcessMemory(hProcess, (UInt32)MutexAAdd, (int)&ModiCode, System.Runtime.InteropServices.Marshal.SizeOf(ModiCode), 0);
                    Console.WriteLine("MutexAAdd={0}", MutexAAdd);
                }
                else
                {
                    Console.WriteLine("打开失败，hProcess <=0, hProcess={0}", hProcess);
                }

                hProcess = 0;
                Console.WriteLine("Press any key to end");
                Console.ReadKey();
            }
            #endregion
        }
    }
}

using System;
using System.Runtime.InteropServices;

namespace Text
{
    class Program
    {
        [DllImport("kernel32.dll ")]
        public static extern uint OpenProcess(UInt32 dwDesiredAccess, bool bInheritHandle, int dwProcessId);
        [DllImport("User32.dll ")]
        public static extern System.IntPtr FindWindowEx(System.IntPtr parent, System.IntPtr childe, string strclass, string strname);
        [DllImport("user32.dll")]
        public static extern uint GetWindowThreadProcessId(IntPtr hwnd, out int pid);
        [DllImport("Kernel32")]
        public static extern int GetProcAddress(int handle, String funcname);
        [DllImport("kernel32", EntryPoint = "GetModuleHandle")]
        public static extern int GetModuleHandle(string