I spent some more Time improving the App.
\nIt now injects a DLL which listens for the Window Activated Event and then closes it. It also listens for Skype Started Event and tries to close the Window and injects the DLL.<\/p>\n
Since DLLs which should be injected can’t be in Managed Code, I had to go back to my C++ knowledge.<\/p>\n
Here are the most important parts described:<\/p>\n
The DLL<\/strong> Calling the unmanaged Code in the Managed C# App<\/strong> Here’s the Code to call the InstallHook:<\/p>\n Here’s the Code to uninstall it:<\/p>\n
\nWell, instead of writing too much I’ll just post the complete code for the DLL:<\/p>\n\r\n#define WIN32_LEAN_AND_MEAN\r\n#include <windows.h>\r\n#include <iostream>\r\n#include <stdio.h>\r\n\r\nHINSTANCE dllInstance;\r\nHHOOK hookHandle;\r\n\r\n\/\/ Search for the Window and Close it\r\nvoid CloseWindow() {\r\n\tHWND hWnd = FindWindow("THomeForm", "Skype Home");\r\n\tif (hWnd != NULL) {\r\n\t\tSendMessage(hWnd, WM_SYSCOMMAND, SC_CLOSE, 0);\r\n\t}\r\n}\r\n\r\n\/\/ Callback for the Timer\r\nVOID CALLBACK TimerProc(HWND hwnd, UINT uMsg, UINT_PTR idEvent, DWORD dwTime) {\r\n\tCloseWindow();\r\n\tKillTimer(NULL, 1);\r\n}\r\n\r\n\/\/ Callback for the Hook\r\nLRESULT CALLBACK WindowHookProc(int code, WPARAM wParam, LPARAM lParam)\r\n{\r\n\tif (code >= 0) {\r\n\t\tswitch(code) {\r\n\t\t\t\/\/case HCBT_ACTIVATE:\r\n\t\t\t\/\/case HCBT_CREATEWND:\r\n\t\t\t\/\/case HSHELL_WINDOWCREATED:\r\n\t\t\tcase HSHELL_WINDOWACTIVATED:\r\n\t\t\t\t\/\/ Get the Class and the Title\r\n\t\t\t\tTCHAR className[255];\r\n\t\t\t\tTCHAR title[255];\r\n\t\t\t\tmemset(className, 0, sizeof(className));\r\n\t\t\t\tmemset(title, 0, sizeof(title));\r\n\t\t\t\tHWND window = (HWND)wParam;\r\n\t\t\t\tint ret = GetClassName(window, className, sizeof(className));\r\n\t\t\t\tret = GetWindowText(window, title, sizeof(title));\r\n\t\t\t\t\/\/ Compare the Class and the Title\r\n\t\t\t\tif (strcmp(className, "THomeForm") == 0 && strcmp(title, "Skype Home") == 0) {\r\n\t\t\t\t\t\/\/ Success, Create a Timer to close the Window\r\n\t\t\t\t\tint m_LoadTimesTimerID = SetTimer(NULL, 1, 1000, TimerProc);\r\n\t\t\t\t}\r\n\t\t\tbreak;\r\n\t\t}\r\n\t}\r\n\treturn CallNextHookEx(hookHandle, code, wParam, lParam);\r\n}\r\n\r\nextern "C" __declspec(dllexport) void InstallHook(int threadID) {\r\n\tint hookID = WH_CBT;\r\n\thookID = WH_SHELL;\r\n\tif (threadID > 0) {\r\n\t\thookHandle = SetWindowsHookEx(hookID, WindowHookProc, dllInstance, threadID);\r\n\t} else {\r\n\t\thookHandle = SetWindowsHookEx(hookID, WindowHookProc, dllInstance, NULL);\r\n\t}\r\n}\r\n\r\nextern "C" __declspec(dllexport) void UninstallHook() {\r\n\tUnhookWindowsHookEx(hookHandle); \r\n}\r\n\r\nBOOL WINAPI DllMain(__in HINSTANCE hinstDLL, __in DWORD fdwReason, __in LPVOID lpvReserved) {\r\n\tdllInstance = hinstDLL;\r\n\treturn TRUE;\r\n}\r\n<\/pre>\n
\nAs you see, there are two exported Functions in the DLL:
\nInstallHook and UninstallHook
\nTo be able to call them, there are some Win32 Stuff and some delegates needed:<\/p>\n\r\n[DllImport("kernel32.dll")]\r\npublic static extern IntPtr LoadLibrary(string dllToLoad);\r\n[DllImport("kernel32.dll")]\r\npublic static extern IntPtr GetProcAddress(IntPtr hModule, string procedureName);\r\n[DllImport("kernel32.dll")]\r\npublic static extern bool FreeLibrary(IntPtr hModule);\r\n\r\n[UnmanagedFunctionPointer(CallingConvention.Cdecl)]\r\npublic delegate void InstallHook(int threadID);\r\n[UnmanagedFunctionPointer(CallingConvention.Cdecl)]\r\npublic delegate void UninstallHook();\r\n<\/pre>\n\r\npublic static void Install()\r\n{\r\n\tIntPtr pDll = LoadLibrary(@"SkypeHomeCloserNativeHelper.dll");\r\n\tif (pDll == IntPtr.Zero)\r\n\t{\r\n\t\tMessageBox.Show("DLL not found");\r\n\t}\r\n\telse\r\n\t{\r\n\t\tIntPtr procAddress = GetProcAddress(pDll, "InstallHook");\r\n\t\tif (procAddress == IntPtr.Zero)\r\n\t\t{\r\n\t\t\tMessageBox.Show("Proc not found");\r\n\t\t}\r\n\t\telse\r\n\t\t{\r\n\t\t\tInstallHook install = (InstallHook)Marshal.GetDelegateForFunctionPointer(procAddress, typeof(InstallHook));\r\n\t\t\tProcess[] procList = Process.GetProcessesByName("Skype");\r\n\t\t\tif (procList.Length > 0)\r\n\t\t\t{\r\n\t\t\t\tint threadID = procList[0].Threads[0].Id;\r\n\t\t\t\tinstall(threadID);\r\n\t\t\t}\r\n\t\t\tbool result = FreeLibrary(pDll);\r\n\t\t}\r\n\t}\r\n}\r\n<\/pre>\n\r\npublic static void Remove()\r\n{\r\n\tIntPtr pDll = LoadLibrary(@"SkypeHomeCloserNativeHelper.dll");\r\n\tif (pDll == IntPtr.Zero)\r\n\t{\r\n\t\tMessageBox.Show("DLL not found");\r\n\t}\r\n\telse\r\n\t{\r\n\t\tIntPtr procAddress = GetProcAddress(pDll, "UninstallHook");\r\n\t\tif (procAddress == IntPtr.Zero)\r\n\t\t{\r\n\t\t\tMessageBox.Show("Proc not found");\r\n\t\t}\r\n\t\telse\r\n\t\t{\r\n\t\t\tUninstallHook uninstall = (UninstallHook)Marshal.GetDelegateForFunctionPointer(procAddress, typeof(UninstallHook));\r\n\t\t\tuninstall();\r\n\t\t\tbool result = FreeLibrary(pDll);\r\n\t\t}\r\n\t}\r\n}\r\n<\/pre>\n