{"id":11277,"date":"2024-03-14T13:44:01","date_gmt":"2024-03-14T13:44:01","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-to-send-a-message-to-the-main-window-using-mfc\/"},"modified":"2025-08-04T09:46:16","modified_gmt":"2025-08-04T09:46:16","slug":"how-to-send-a-message-to-the-main-window-using-mfc","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-to-send-a-message-to-the-main-window-using-mfc\/","title":{"rendered":"MFC: Send Message to Main Window"},"content":{"rendered":"<p>To send a message to the main window in an MFC application, you can use the AfxGetMainWnd function to obtain a pointer to the main window, and then use the PostMessage or SendMessage function to send the message.<\/p>\n<p>For example, you can use the following code to send a custom message to the main window in an MFC application:<\/p>\n<pre class=\"post-pre\"><code><span class=\"hljs-comment\">\/\/ \u83b7\u53d6\u4e3b\u7a97\u53e3\u6307\u9488<\/span>\r\nCWnd* pMainWnd = <span class=\"hljs-built_in\">AfxGetMainWnd<\/span>();\r\n\r\n<span class=\"hljs-comment\">\/\/ \u53d1\u9001\u6d88\u606f\u7ed9\u4e3b\u7a97\u53e3<\/span>\r\nUINT msg = WM_USER + <span class=\"hljs-number\">1<\/span>; <span class=\"hljs-comment\">\/\/ \u81ea\u5b9a\u4e49\u6d88\u606f<\/span>\r\npMainWnd-&gt;<span class=\"hljs-built_in\">PostMessage<\/span>(msg, <span class=\"hljs-number\">0<\/span>, <span class=\"hljs-number\">0<\/span>);\r\n<\/code><\/pre>\n<p>For example, this custom message can be handled in the message mapping function of the main window class.<\/p>\n<pre class=\"post-pre\"><code><span class=\"hljs-built_in\">BEGIN_MESSAGE_MAP<\/span>(CMainFrame, CFrameWnd)\r\n    <span class=\"hljs-built_in\">ON_MESSAGE<\/span>(WM_USER + <span class=\"hljs-number\">1<\/span>, OnCustomMessage)\r\n<span class=\"hljs-built_in\">END_MESSAGE_MAP<\/span>()\r\n\r\n<span class=\"hljs-function\">LRESULT <span class=\"hljs-title\">CMainFrame::OnCustomMessage<\/span><span class=\"hljs-params\">(WPARAM wParam, LPARAM lParam)<\/span>\r\n<\/span>{\r\n    <span class=\"hljs-comment\">\/\/ \u5904\u7406\u81ea\u5b9a\u4e49\u6d88\u606f<\/span>\r\n    <span class=\"hljs-keyword\">return<\/span> <span class=\"hljs-number\">0<\/span>;\r\n}\r\n<\/code><\/pre>\n<p>By using this method, it is easy to send messages to the main window in an MFC application and handle these messages in the main window class.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>To send a message to the main window in an MFC application, you can use the AfxGetMainWnd function to obtain a pointer to the main window, and then use the PostMessage or SendMessage function to send the message. For example, you can use the following code to send a custom message to the main window [&hellip;]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[14490,8569,14489,8691,14491],"class_list":["post-11277","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-afxgetmainwnd","tag-mfc","tag-postmessage","tag-sendmessage","tag-wm_user"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>MFC: Send Message to Main Window - Blog - Silicon Cloud<\/title>\n<meta name=\"description\" content=\"Learn to send messages to MFC main window using AfxGetMainWnd, PostMessage\/Includes code example for custom WM_USER messages.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/blog\/how-to-send-a-message-to-the-main-window-using-mfc\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"MFC: Send Message to Main Window\" \/>\n<meta property=\"og:description\" content=\"Learn to send messages to MFC main window using AfxGetMainWnd, PostMessage\/Includes code example for custom WM_USER messages.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/blog\/how-to-send-a-message-to-the-main-window-using-mfc\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - 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