\nA customer wanted to prevent multiple copies of their program\nfrom being grouped on the taskbar.\nThey didn’t give an explanation why,\nbut let’s assume that they are doing this for honorable purposes\nrather than as a way to annoy the user.\nFor example, maybe their program is really multiple applications\nbundled inside a single EXE file for convenience.\n<\/p>\n
\nThe information you need to do this is in MSDN under\n\nApplication User Model IDs<\/a>,\nspecifically in the\n\nWhere to assign an AppUserModelID<\/i><\/a> section.\nI’ll assume you’ve read the guidance there, and I’m just going to dive\ninto the implementation.\n<\/p>\n \nSuppose our scratch program can serve\n\nboth as a floor wax and as a dessert topping<\/a>.\nIt decides on the mode based on a command line switch.\n<\/p>\n \nRun this program a few times, some with the\n \nThe next level of fancy-pants behavior is to give different\nAppIDs to different windows within a single process.\nYou might do this if your combination floor wax\/dessert topping\nprogram actually runs both modes inside the same process.\nSomething like this:\n<\/p>\n \nThis time, instead of setting the application ID globally,\nwe set it on a per-window basis.\nWhen you run this program, you can press “f” to open a new floor wax window\nor “d” to open a new dessert topping window.\nAs before, observe that the two types of windows group separately.\n<\/p>\n \nThe last detail is setting the \nNext time, we’ll look at another reason you might want\nto customize how your application group on the taskbar\nin Windows 7.<\/p>\n","protected":false},"excerpt":{"rendered":" A customer wanted to prevent multiple copies of their program from being grouped on the taskbar. They didn’t give an explanation why, but let’s assume that they are doing this for honorable purposes rather than as a way to annoy the user. For example, maybe their program is really multiple applications bundled inside a single […]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-6833","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":" A customer wanted to prevent multiple copies of their program from being grouped on the taskbar. They didn’t give an explanation why, but let’s assume that they are doing this for honorable purposes rather than as a way to annoy the user. For example, maybe their program is really multiple applications bundled inside a single […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/6833","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=6833"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/6833\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=6833"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=6833"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=6833"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n#include <shlobj.h><\/font>\nint WINAPI WinMain(HINSTANCE hinst, HINSTANCE hinstPrev,\n LPSTR lpCmdLine, int nShowCmd)\n{\n MSG msg;\n HWND hwnd;\n g_hinst = hinst;\n if (!InitApp()) return 0;\n BOOL fDessert = strcmp(lpCmdLine, \"-dessert\") == 0;\n SetCurrentProcessExplicitAppUserModelID(fDessert ?\n L\"Contoso.LitWare.DessertTopping\" :\n L\"Contoso.LitWare.FloorWax\");<\/font>\n if (SUCCEEDED(CoInitialize(NULL))) {\/* In case we use COM *\/\n hwnd = CreateWindow(\n TEXT(\"Scratch\"), \/* Class Name *\/\n fDessert ? TEXT(\"Dessert topping\") : TEXT(\"Floor wax\"),<\/font>\n WS_OVERLAPPEDWINDOW, \/* Style *\/\n CW_USEDEFAULT, CW_USEDEFAULT, \/* Position *\/\n CW_USEDEFAULT, CW_USEDEFAULT, \/* Size *\/\n NULL, \/* Parent *\/\n NULL, \/* No menu *\/\n hinst, \/* Instance *\/\n 0); \/* No special parameters *\/\n ...\n}\n<\/pre>\n-dessert<\/code> switch and some without.\nObserve that the dessert versions and non-dessert versions\ngroup separately.\n<\/p>\n\n#include <shellapi.h>\n#include <propkey.h>\n#include <propvarutil.h>\n#include <shlobj.h><\/font>\nint g_cWindows = 0;<\/font>\nBOOL\nOnCreate(HWND hwnd, LPCREATESTRUCT lpcs)\n{\n ++g_cWindows;<\/font>\n return TRUE;\n}\nvoid\nOnDestroy(HWND hwnd)\n{\n if (--g_cWindows == 0)<\/font> PostQuitMessage(0);\n}\nHWND\nCreateTaskWindow(BOOL fDessert, int nShowCmd)\n{\n HWND hwnd = CreateWindow(\n TEXT(\"Scratch\"), \/* Class Name *\/\n fDessert ? TEXT(\"Dessert topping\") : TEXT(\"Floor wax\"),<\/font>\n WS_OVERLAPPEDWINDOW, \/* Style *\/\n CW_USEDEFAULT, CW_USEDEFAULT, \/* Position *\/\n CW_USEDEFAULT, CW_USEDEFAULT, \/* Size *\/\n NULL, \/* Parent *\/\n NULL, \/* No menu *\/\n g_hinst, \/* Instance *\/\n 0); \/* No special parameters *\/\n if (hwnd) {\n IPropertyStore *pps;\n HRESULT hr = SHGetPropertyStoreForWindow(hwnd, IID_PPV_ARGS(&pps));\n if (SUCCEEDED(hr)) {\n IPropertyStore_SetValue<\/a>(pps, PKEY_AppUserModel_ID,\n fDessert ?\n L\"Contoso.LitWare.DessertTopping\" :\n L\"Contoso.LitWare.FloorWax\");\n pps->Release();\n }\n ShowWindow(hwnd, nShowCmd);\n }\n return hwnd;\n}\nvoid\nOnChar(HWND hwnd, TCHAR ch, int cRepeat)\n{\n switch (ch) {\n case 'd': CreateTaskWindow(TRUE, SW_SHOWNORMAL); break;\n case 'f': CreateTaskWindow(FALSE, SW_SHOWNORMAL); break;\n }\n}\n HANDLE_MSG(hwnd, WM_CHAR, OnChar);<\/font>\nint WINAPI WinMain(HINSTANCE hinst, HINSTANCE hinstPrev,\n LPSTR lpCmdLine, int nShowCmd)\n{\n MSG msg;\n HWND hwnd;\n g_hinst = hinst;\n if (!InitApp()) return 0;\n BOOL fDessert = strcmp(lpCmdLine, \"-dessert\") == 0;<\/font>\n \/\/ SetCurrentProcessExplicitAppUserModelID(...);<\/strike><\/font>\n if (SUCCEEDED(CoInitialize(NULL))) {\/* In case we use COM *\/\n hwnd = CreateTaskWindow(fDessert, nShowCmd);<\/font>\n \/\/ ShowWindow(hwnd, nShowCmd);<\/strike><\/font>\n ...\n}\n<\/pre>\nSystem.AppUserModel.ID<\/code>\nproperty on the shortcuts used to launch these programs.\nYou can do this from MSI by adding an entry to your\nMsiShortcutProperty<\/code> table,\nor if you create your shortcuts programmatically, you do this by\nsetting the property yourself:\n<\/p>\n\n CComPtr<IShellLink> spsl;\n spsl.CoCreateInstance(CLSID_ShellLink);\n spsl->SetPath(TEXT(\"C:\\\\Path\\\\to\\\\scratch.exe\"));\n CComQIPtr<IPropertyStore> spps(spsl);\n IPropertyStore_SetValue(spps, PKEY_AppUserModel_ID,\n L\"Contoso.LitWare.FloorWax\");\n spps->Commit();<\/font>\n CComQIPtr<IPersistFile>(spsl)->Save(L\"LitWare Floor Wax.lnk\", TRUE);\n<\/pre>\n