var n = 0; var arr = document.getElementsByTagName('img'); document.onkeydown = function (event) { for (var i = 0; i < arr.length; i++) { arr[i].style.display = 'none'; } var e = event || window.event || arguments.callee.caller.arguments[0]; if (e && e.keyCode == 37) { // 按 <- n--; if (n < 0) { n = arr.length - 1; } } if (e && e.keyCode == 39) { // 按 -> n++; if (n >= arr.length) { n = 0; } } arr[n].style.display = 'block'; };
