https://www.imokin.jp/js/lib_stop_focus.js

1/*
2 *ブラウザの戻る機能無効化
3 * */
4jQuery(document).ready(function(){
5
6	its_ignore_key = function(e){
7		if(!e){
8			eve = window.event;
9		}
10		else {
11			eve = e;
12		}
13		var	keyCode		=	eve.keyCode;
14		var	ctrlKey		=	eve.ctrlKey;
15		var	altKey		=	eve.altKey;
16		var	blKey		=	true;
17		var srcObj = eve.srcElement || eve.target;
18
19		var F5 = 116;
20		var R = 82;
21		var BACKSPACE = 8;
22		var LEFT_ARROW = 37;
23		//ファンクションキー リロード無効
24		if(keyCode == F5){
25			blKey = false;
26		//Ctrl + R
27		}else if(ctrlKey && keyCode == R){
28			blKey = false;
29		}else if (keyCode == BACKSPACE) {
30			//backspaceキャンセル	[戻る]を制御
31			//フォームで[backspace]は必要
32			switch (srcObj.tagName) {
33				//ファームに対する動作は許可
34				case "INPUT":
35				case "TEXTAREA":
36					//readOnlyはNG
37					if(srcObj.readOnly !== undefined && srcObj.readOnly == true){
38						blKey = false;
39					}
40					break;
41				default:
42					blKey = false;
43					break;
44			}
45		}
46		//Alt+左による戻るアクション
47		else if(altKey && keyCode == LEFT_ARROW){
48			blKey = false;
49		}
50
51		if (!blKey){
52			if(!e) {
53				eve.keyCode = null;
54			}
55			else {
56				eve.stopPropagation();
57				eve.preventDefault();
58				eve.keyCode = null;
59			}
60		}
61		//blKey true/false:ブラウザでキーイベントを処理する/しない
62		return blKey;
63	};
64
65	var d = window.document;
66	if (d.addEventListener){
67		d.addEventListener("keydown", its_ignore_key, false);
68	}else if(d.attachEvent){
69		d.attachEvent('onkeydown',its_ignore_key);
70	}
71});