C# DLL 注入无法正常运行

Question

我正在尝试用 C# 制作 DLL 注入器 Windows 窗体应用程序。当我在进程（例如记事本）上运行注入时，它不会执行任何操作。我不确定是我正在使用的 DLL 还是我注入它的方式。我对 C# 很陌生，所以如果我所说的有任何不清楚的地方，请询问。

我希望在注入时打开一个消息框来打招呼，但它并没有这样做。 我也没有收到任何错误消息。

这是附加 DLL 的代码：

[DllImport("kernel32.dll")]
        public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        public static extern IntPtr GetModuleHandle(string lpModuleName);

        [DllImport("kernel32", CharSet = CharSet.Ansi, ExactSpelling = true, SetLastError = true)]
        static extern IntPtr GetProcAddress(IntPtr hModule, string procName);

        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
        static extern IntPtr VirtualAllocEx(IntPtr hProcess, IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);

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

        [DllImport("kernel32.dll")]
        static extern IntPtr CreateRemoteThread(IntPtr hProcess, IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);

        // privileges
        const int PROCESS_CREATE_THREAD = 0x0002;
        const int PROCESS_QUERY_INFORMATION = 0x0400;
        const int PROCESS_VM_OPERATION = 0x0008;
        const int PROCESS_VM_WRITE = 0x0020;
        const int PROCESS_VM_READ = 0x0010;

        // used for memory allocation
        const uint MEM_COMMIT = 0x00001000;
        const uint MEM_RESERVE = 0x00002000;
        const uint PAGE_READWRITE = 4;

        public static int Inject(string PN, string dllName)
        {
            Process targetProcess = Process.GetProcessesByName(PN)[0];

            IntPtr procHandle = OpenProcess(PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION | PROCESS_VM_OPERATION | PROCESS_VM_WRITE | PROCESS_VM_READ, false, targetProcess.Id);

            IntPtr loadLibraryAddr = GetProcAddress(GetModuleHandle("kernel32.dll"), "LoadLibraryA");

            IntPtr allocMemAddress = VirtualAllocEx(procHandle, IntPtr.Zero, (uint)((dllName.Length + 1) * Marshal.SizeOf(typeof(char))), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);

            UIntPtr bytesWritten;
            WriteProcessMemory(procHandle, allocMemAddress, Encoding.Default.GetBytes(dllName), (uint)((dllName.Length + 1) * Marshal.SizeOf(typeof(char))), out bytesWritten);

            CreateRemoteThread(procHandle, IntPtr.Zero, 0, loadLibraryAddr, allocMemAddress, 0, IntPtr.Zero);

            return 4;
        }

这是附加到记事本的 DLL：

// dllmain.cpp : Defines the entry point for the DLL application.
#include "pch.h"
#include <tchar.h>

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        MessageBox(NULL, _TEXT("Hello"), _TEXT("Hello"), 0);
        break;
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}