\nToday we’re going to dump information about the user’s wallpaper\nsettings on multiple monitors.\n<\/p>\n
\nThe idea is simple. You use the\n \nThe program proceeds in a few basic steps.\n<\/p>\n \nWe create the \nOur first question is,\n“Is the same wallpaper being shown on all monitors?”\nTo determine that, we call\n \nTo get information about the wallpaper on each monitor,\nwe iterate through them,\nfirst asking for the monitor device path,\nsince that is how the\n \nAnd that’s it.\nYou can juice up this program by asking for wallpaper\npositioning information,\nand if you are feeling really adventuresome,\nyou can use the Today we’re going to dump information about the user’s wallpaper settings on multiple monitors. The idea is simple. You use the IDesktopWallpaper interface on the DesktopWallpaper object to get information about the desktop wallpaper. It will tell you the wallpaper positioning information, whether a single image is being used for all monitors, where those monitors […]<\/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-833","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":" Today we’re going to dump information about the user’s wallpaper settings on multiple monitors. The idea is simple. You use the IDesktopWallpaper interface on the DesktopWallpaper object to get information about the desktop wallpaper. It will tell you the wallpaper positioning information, whether a single image is being used for all monitors, where those monitors […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/833","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=833"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/833\/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=833"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=833"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=833"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}IDesktopWallpaper<\/code> interface on the\nDesktopWallpaper<\/code> object\nto get information about the desktop wallpaper.\nIt will tell you the wallpaper positioning information,\nwhether a single image is being used for all monitors,\nwhere those monitors are,\nand which image is on which monitor.\n<\/p>\n\n#define UNICODE\n#define _UNICODE<\/a>\n#define STRICT\n#include <windows.h>\n#include <shlobj.h>\n#include <atlbase.h>\n#include <atlalloc.h>\n#include <stdio.h> \/\/ horrors! mixing C and C++!\nint __cdecl wmain(int, wchar_t **)\n{\n CCoInitialize<\/a> init;\n \/\/ Create the DesktopWallpaper object\n CComPtr<IDesktopWallpaper> spdw;\n CoCreateInstance(CLSID_DesktopWallpaper, nullptr, CLSCTX_ALL,\n IID_PPV_ARGS(&spdw));\n \/\/ See if there is a single wallpaper on all monitors.\n CComHeapPtr<wchar_t> spszCommonWallpaper;\n HRESULT hr = spdw->GetWallpaper(nullptr, &spszCommonWallpaper);\n switch (hr) {\n case S_OK:\n printf(\"Same wallpaper on all monitors: %ls\\n\",\n static_cast<wchar_t *>(spszCommonWallpaper));\n break;\n case S_FALSE:\n printf(\"Different wallpaper on each monitor\\n\");\n break;\n default:\n printf(\"Mysterious error: 0x%08x\\n\", hr);\n break;\n }\n \/\/ Get the number of monitors,\n UINT count;\n spdw->GetMonitorDevicePathCount(&count);\n printf(\"There are %d monitors\\n\", count);\n \/\/ Print information about each monitor.\n for (UINT i = 0; i < count; i++) {\n \/\/ Get the device path for the monitor.\n CComHeapPtr<wchar_t> spszId;\n spdw->GetMonitorDevicePathAt(i, &spszId);\n printf(\"path[%d] = %ls\\n\",\n i, static_cast<wchar_t *>(spszId));\n \/\/ Get the monitor location.\n RECT rc;\n spdw->GetMonitorRECT(spszId, &rc);\n printf(\"rect = (%d, %d, %d, %d)\\n\",\n rc.left, rc.top, rc.bottom, rc.right);\n \/\/ Get the wallpaper on that monitor.\n CComHeapPtr<wchar_t> spszWallpaper;\n hr = spdw->GetWallpaper(spszId, &spszWallpaper);\n printf(\"image = %ls\\n\",\n static_cast<wchar_t *>(spszWallpaper));\n }\n return 0;\n}\n<\/pre>\n
DesktopWallpaper<\/code> object.\nThat object will give us the answers to our questions.\n<\/p>\nIDesktopWallpaper::GetWallpaper<\/code>\nand specify nullptr<\/code> as the monitor ID.\nThe call succeeds with S_OK<\/code> if the same wallpaper\nis shown on all monitors (in which case the shared wallpaper\nis returned).\nIt succeeds with S_FALSE<\/code> if each monitor has a different\nwallpaper.\n<\/p>\nDesktopWallpaper<\/code> object identifies monitors.\nFor each monitor, we ask for its location\nand the wallpaper for that monitor.\nNote that if the monitor is not displaying a wallpaper at all,\nthe GetWallpaper<\/code> method succeeds\nbut returns an empty string.\n<\/p>\nSetWallpaper<\/code>\nmethod to change the wallpaper.<\/p>\n","protected":false},"excerpt":{"rendered":"