{"id":6201,"date":"2024-08-03T11:41:15","date_gmt":"2024-08-03T02:41:15","guid":{"rendered":"https:\/\/taitan916.info\/blog\/?p=6201"},"modified":"2024-05-19T17:56:37","modified_gmt":"2024-05-19T08:56:37","slug":"post-6201","status":"publish","type":"post","link":"https:\/\/taitan916.info\/blog\/archives\/6201","title":{"rendered":"JavaScript\u306eIntersectionObserver\u3092\u5229\u7528\u3057\u3066\u6307\u5b9a\u3057\u305f\u8981\u7d20\u304c\u8868\u793a\u3055\u308c\u3066\u3044\u308b\u304b\u78ba\u8a8d\u3059\u308b\u65b9\u6cd5"},"content":{"rendered":"

\u30d6\u30e9\u30a6\u30b6\u4e0a\u3067\u6307\u5b9a\u3057\u305f\u8981\u7d20\u304c\u8868\u793a\u3055\u308c\u3066\u3044\u308b\u304b\u30c1\u30a7\u30c3\u30af\u3057\u3001\u8868\u793a\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306f\u4f55\u3089\u304b\u306e\u30a4\u30d9\u30f3\u30c8\u3092\u5b9f\u884c\u3057\u305f\u3044\u3002JavaScript\u306escroll\u30a4\u30d9\u30f3\u30c8\u3067\u5bfe\u5fdc\u3057\u3088\u3046\u3068\u601d\u3063\u305f\u304c\u3001\u3053\u308c\u3060\u3068\u30b9\u30af\u30ed\u30fc\u30eb\u306e\u5ea6\u306b\u5b9f\u884c\u3055\u308c\u308b\u306e\u3067\u8ca0\u8377\u304c\u304b\u304b\u308b\u3002IntersectionObserver\u3092\u4f7f\u3046\u3053\u3068\u3067\u8ca0\u8377\u8efd\u6e1b\u3067\u304d\u308b\u307f\u305f\u3044\u306a\u306e\u3067\u5b9f\u88c5\u65b9\u6cd5\u3092\u30e1\u30e2\u3002<\/p>\n

 <\/p>\n

\u30b5\u30f3\u30d7\u30eb<\/h2>\n

https:\/\/taitan916.info\/sample\/IntersectionObserver\/<\/a><\/p>\n

\u30b9\u30af\u30ed\u30fc\u30eb\u3057\u3066\u300c\u30bf\u30fc\u30b2\u30c3\u30c8\u300d\u90e8\u5206\u304c\u8868\u793a\u3055\u308c\u308b\u3068\u30da\u30fc\u30b8\u4e0a\u90e8\u304c\u300c\u975e\u8868\u793a\u2192\u8868\u793a\u300d\u306b\u5207\u308a\u66ff\u308f\u308b\u7b48\u3002<\/p>\n

 <\/p>\n

\u5b9f\u88c5\u65b9\u6cd5<\/h2>\n

\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9<\/h3>\n
<div class=\"contents\">\u30b3\u30f3\u30c6\u30f3\u30c4<\/div>\r\n<div class=\"target\">\u30bf\u30fc\u30b2\u30c3\u30c8<\/div>\r\n<div class=\"contents\">\u30b3\u30f3\u30c6\u30f3\u30c4<\/div>\r\n<div class=\"check\"><\/div>\r\n\r\n<script>\r\nconst target = document.querySelector(`.target`);\r\nconst options = {\r\n    root: null, \/\/\u30bf\u30fc\u30b2\u30c3\u30c8\u304c\u898b\u3048\u308b\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d\u3059\u308b\u305f\u3081\u306e\u30d3\u30e5\u30fc\u30dd\u30fc\u30c8\r\n    rootMargin: `0px`, \/\/root\u306e\u5468\u308a\u306e\u30de\u30fc\u30b8\u30f3\r\n    threshold: 1, \/\/\u30bf\u30fc\u30b2\u30c3\u30c8\u304c\u3069\u306e\u304f\u3089\u3044\u306e\u5272\u5408\u3067\u898b\u3048\u3066\u3044\u308b\u304b\r\n};\r\nconst observer = new IntersectionObserver(displayCheck, options);\r\nobserver.observe(target);\r\n\r\nfunction displayCheck(entries){\r\n    entries.forEach(entry => {\r\n        const text = ( entry.isIntersecting ) ? `\u8868\u793a` : `\u975e\u8868\u793a`;\r\n        document.querySelector(`.check`).innerText = text;\r\n    });\r\n}<\/pre>\n
 <\/p>\n
\u30ea\u30d5\u30a1\u30ec\u30f3\u30b9<\/h2>\n
https:\/\/developer.mozilla.org\/ja\/docs\/Web\/API\/IntersectionObserver<\/a><\/p>\n
https:\/\/developer.mozilla.org\/ja\/docs\/Web\/API\/Intersection_Observer_API<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
\u30d6\u30e9\u30a6\u30b6\u4e0a\u3067\u6307\u5b9a\u3057\u305f\u8981\u7d20\u304c\u8868\u793a\u3055\u308c\u3066\u3044\u308b\u304b\u30c1\u30a7\u30c3\u30af\u3057\u3001\u8868\u793a\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306f\u4f55\u3089\u304b ... <\/p>\n","protected":false},"author":1,"featured_media":1067,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-6201","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-javascript"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t