进程间通讯 —— 共享内存

BOOL SendProcessMessage()
{
HWND hWnd;

hWnd = FindWindow(NULL, "Recv");  // 查找接收端窗口

if (!hWnd)
{
MessageBox(g_hWnd, "找不到通信进程", "error", MB_OK | MB_ICONERROR);
return FALSE;
}

DWORD dwProcessId;
GetWindowThreadProcessId(hWnd, &dwProcessId);  // 获取句柄窗口所在进程ID

HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, dwProcessId);  // 获取进程句柄

if (!hProcess)
{
MessageBox(g_hWnd, "打开进程失败", "error", MB_OK | MB_ICONERROR);
return FALSE;
}

LPVOID lpAddress = VirtualAllocEx(hProcess, NULL, 1024, MEM_COMMIT, PAGE_EXECUTE_READWRITE);  // 在目标进程中申请一段内存空间

if (!lpAddress)
{
MessageBox(g_hWnd, "在进程中分配内存失败", "error", MB_OK | MB_ICONERROR);
return FALSE;
}

char buf[] = "hello world!";

if (!WriteProcessMemory(hProcess, lpAddress, buf, sizeof(buf), NULL))  // 在内存空间中写入内容
{
MessageBox(g_hWnd, "在进程分配内存中写入数据失败", "error", MB_OK | MB_ICONERROR);
return FALSE;
}

SendMessage(hWnd, WM_READMEMORY, NULL, (LPARAM)lpAddress);  // 向目标窗口发送消息

Sleep(100);  // 放弃CPU执行时间片给其它进程

VirtualFreeEx(hProcess, lpAddress, 0, MEM_RELEASE);  // 释放内存

return TRUE;
}

case WM_READMEMORY:

char buf[1024];

ReadProcessMemory(GetCurrentProcess(),  (LPVOID)lParam,  buf,  sizeof(buf),  NULL);  // 在内存中读取数据

MessageBox(g_hWnd, buf, "", MB_OK);

break;