JS——模拟百度搜索

注意事项：

1、for循环移除子节点时，其长度是变化的

2、在文档流中，input、img、p等标签与其他标签有3px的距离，利用左浮动，可以消除3px距离

3、背景图片定位时，第一个值是x轴方向的值，第二值是y轴方向的值

4、大多时候input标签outline属性时都设置为none，然后为其注册事件改变它的border颜色

5、indexOf方法返回符合条件的字符串的索引值，没有符合条件的情况下返回-1

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        .box1 {
            width: 500px;
            height: 36px;
            margin: 0 auto;
            margin-top: 50px;
            position: relative;
        }

        input[type="text"] {
            float: left;
            width: 355px;
            height: 34px;
            padding-left: 5px;
            padding-right: 40px;
            border: 1px solid #b8b8b8;
            border-right: 0px;
            /*text-indent: 1em;*/
            outline: none;
        }

        span {
            position: absolute;
            width: 18px;
            height: 16px;
            top: 50%;
            margin-top: -8px;
            right: 106px;
            background: url("image/baidu.png");
        }

        span:hover {
            cursor: pointer;
            background-position: 0 -20px;
        }

        button {
            float: left;
            width: 99px;
            height: 36px;
            background-color: #38f;
            border: 1px solid #38f;
            outline: none;

        }

        button:hover {
            background-color: #317ef3;
            cursor: pointer;
            box-shadow: 1px 1px 1px #ccc;
        }

        ul {
            list-style: none;
            width: 399px;
            background-color: pink;
            border: 1px solid #b8b8b8;
            border-top: none;
        }

        li {
            padding-left: 5px;
        }

        li:hover {
            background-color: #b8b8b8;
        }
    </style>
</head>
<body>
<div class="box1">
    <input type="text">
    <span></span>
    <button>搜索</button>
    <ul>

    </ul>
</div>
</body>
<script>
    var arr = ["a", "ab", "abc", "abcd", "abcde", "abcdef"];
    var inpEle = document.getElementsByTagName("input")[0];
    var ulEle = document.getElementsByTagName("ul")[0];
    //input获得焦点后改变border颜色并且搜索相关词汇
    inpEle.onfocus = function () {
        this.style.borderTop = "1px solid #38f";
        this.style.borderLeft = "1px solid #38f";
        this.style.borderBottom = "1px solid #38f";
        searchWords();
    }
    //input离开焦点后改变border颜色并且搜索相关词汇
    inpEle.onblur = function () {
        this.style.borderTop = "1px solid #b8b8b8";
        this.style.borderLeft = "1px solid #b8b8b8";
        this.style.borderBottom = "1px solid #b8b8b8";
        for (var i = 0; i < ulEle.children.length;) {
            ulEle.removeChild(ulEle.children[i]);
        }
    }
    //input注册键盘弹起事件
    inpEle.onkeyup = searchWords;
    //搜索关联词汇
    function searchWords() {
        if (inpEle.value == "") {
            for (var i = 0; i < ulEle.children.length;) {
                ulEle.removeChild(ulEle.children[i]);
            }
            return;
        }
        //ulEle移除其子节点时，它的长度是变化的
        for (var i = 0; i < ulEle.children.length;) {
            ulEle.removeChild(ulEle.children[i]);
        }
        for (var i = 0; i < arr.length; i++) {
            if (arr[i].indexOf(inpEle.value) === 0) {
                var liEle = document.createElement("li");
                liEle.innerHTML = arr[i];
                ulEle.appendChild(liEle);
            }
        }
    }
</script>
</html>

posted @ 2017-11-25 03:14  var_obj  阅读(244)  评论(0)  编辑  收藏  举报