原生js写的思路如下
第一步：fnInit实现初始化一些字段
第二步：加载搜索框的div
第三步：实现search功能，删除原节点并加载新节点
第四步：点击或者回车的时候设置value
代码：
autoComplete.js
/**
* @summary AutoComplete
* @description 输入框自动检索下拉选项
* @version 0.0.1
* @file autoComplete.js
* @author cangowu
* @contact 1138806090@qq.com
* @copyright Copyright 2016 cangoWu.
*
* 这是一个基于原生js的自动完成搜索的下拉输入框，
* 可以通过移动鼠标上下键回车以及直接用鼠标点击
* 选中搜索的选项，在一些关键的地方都有注释
*
* 实例参见:
* CSDN博客：http://blog.csdn.net/wzgdjm/article/details/51122615
* Github：https://github.com/cangowu/autoComplete
*
*/
(function () {
function AutoComplete() {
if (!(this instanceof AutoComplete)) {
return new AutoComplete();
}
this.sSearchValue = '';
this.index = -1;
}
AutoComplete.prototype = {
fnInit: function (option) {//初始化基本信息
var oDefault = {
id: '', //控件id
data: [], //数据
paraName: '',
textFiled: '', //显示的文字的属性名
valueFiled: '', //获取value的属性名
style: {}, //显示的下拉div的样式设置
url: '', //ajax请求的url
select: function () {
}, //选择选项时触发的事件
};
var _option = option;
this.sId = _option.id || oDefault.id;
this.aData = _option.data || oDefault.data;
this.paraName = _option.paraName || oDefault.paraName;
this.sTextFiled = _option.textFiled || oDefault.textFiled;
this.sValueFiled = _option.valueFiled || oDefault.valueFiled;
this.style = _option.style || oDefault.style;
this.sUrl = _option.url || oDefault.url;
this.fnSelect = _option.select || oDefault.select;
this.sDivId = this.sId + new Date().getTime();//加载选项额divid
//判断如果传入了url,没有传入data数据，就ajax获取数据，否则使用data取数据
if (this.sUrl !== '' && this.aData.length === 0) {
var that = this;
this.util.fnGet(this.sUrl, function (data) {
console.log(eval(data));
that.aData = eval(data);
}, 10);
}
//给aData排序
var sTextField = this.sTextFiled;
this.aData.sort(function (a, b) {
return a[sTextField] > b[sTextField];
});
//获取控件
this.domInput = document.getElementById(this.sId);
//this.domDiv = document.getElementById(this.sDivId);
},
fnRender: function () {//渲染一些必须的节点
var that = this;
//生成一个对应的div，承载后面的一些选项的
if (that.sDivId) {
var domDiv = document.createElement('div');
domDiv.id = that.sDivId;
domDiv.style.background = '#fff';
domDiv.style.width = that.domInput.offsetWidth - 2 + 'px';
domDiv.style.position = 'absolute';
domDiv.style.border = '1px solid #a9a9a9';
domDiv.style.display = 'none';
that.util.fnInsertAfter(domDiv, that.domInput);
//加载之后才能将domDiv赋值为
this.domDiv = document.getElementById(this.sDivId);
}
//给input添加keyup事件
that.util.fnAddEvent(that.domInput, 'keyup', function (event) {
that.fnSearch(event);
});
},
fnSearch: function (event) {
//判断如果不是回车键，上键下键的时候执行搜索
if (event.keyCode != 13 && event.keyCode != 38 && event.keyCode != 40) {
this.fnLoadSearchContent();
this.fnShowDiv();
} else {//搜索之后监测键盘事件
var length = this.domDiv.children.length;
if (event.keyCode == 40) {
++this.index;
if (this.index >= length) {
this.index = 0;
} else if (this.index == length) {
this.domInput.value = this.sSearchValue;
}
this.domInput.value = this.domDiv.childNodes[this.index].text;
this.fnChangeClass();
}
else if (event.keyCode == 38) {
this.index--;
if (this.index <= -1) {
this.index = length - 1;
} else if (this.index == -1) {
this.obj.value = this.sSearchValue;
}
this.domInput.value = this.domDiv.childNodes[this.index].text;
this.fnChangeClass();
}
else if (event.keyCode == 13) {
this.fnLoadSearchContent();
this.fnShowDiv();
//this.domDiv.style.display = this.domDiv.style.display === 'none' ? 'block' : 'none';
this.index = -1;
} else {
this.index = -1;
}
}
},
fnLoadSearchContent: function () {
//删除所有的子节点
while (this.domDiv.hasChildNodes()) {
this.domDiv.removeChild(this.domDiv.firstChild);
}
//设置search的值
this.sSearchValue = this.domInput.value;
//如果值为空的时候选择退出
var sTrimSearchValue = this.sSearchValue.replace(/(^s*)|(s*$)/g, '');
if (sTrimSearchValue == "") {
this.domDiv.style.display = 'none';
return;
}
try {
var reg = new RegExp("(" + sTrimSearchValue + ")", "i");
}
catch (e) {
return;
}
//搜索并增加新节点
var nDivIndex = 0;
for (var i = 0; i < this.aData.length; i++) {
if (reg.test(this.aData[i][this.sTextFiled])) {
var domDiv = document.createElement("div");
//div.className="auto_onmouseout";
domDiv.text = this.aData[i][this.sTextFiled];
domDiv.onclick = this.fnSetValue(this);
domDiv.onmouseover = this.fnAutoOnMouseOver(this, nDivIndex);
domDiv.innerHTML = this.aData[i][this.sTextFiled].replace(reg, "<strong>$1</strong>");//搜索到的字符粗体显示
this.domDiv.appendChild(domDiv);
nDivIndex++;
}
}
},
fnSetValue: function (that) {
return function () {
that.domInput.value = this.text;
that.domDiv.style.display = 'none';
}
},
fnAutoOnMouseOver: function (that, idx) {
return function () {
that.index = idx;
that.fnChangeClass();
}
},
fnChangeClass: function () {
var that = this;
var length = that.domDiv.children.length;
for (var j = 0; j < length; j++) {
if (j != that.index) {
that.domDiv.childNodes[j].style.backgroundColor = '';
that.domDiv.childNodes[j].style.color = '#000';
} else {
that.domDiv.childNodes[j].style.backgroundColor = 'blue';
that.domDiv.childNodes[j].style.color = '#fff';
}
}
},
fnShowDiv: function () {
if (this.domDiv.children.length !== 0) {
this.domDiv.style.display = this.domDiv.style.display === 'none' ? 'block' : 'none';
}
},
util: {//公共接口方法
fnInsertAfter: function (ele, targetEle) {
var parentnode = targetEle.parentNode || targetEle.parentElement;
if (parentnode.lastChild == targetEle) {
parentnode.appendChild(ele);
} else {
parentnode.insertBefore(ele, targetEle.nextSibling);
}
},
fnAddEvent: function (ele, evt, fn) {
if (document.addEventListener) {
ele.addEventListener(evt, fn, false);
} else if (document.attachEvent) {
ele.attachEvent('on' + (evt == "input" ? "propertychange" : evt), fn);
} else {
ele['on' + (evt == "input" ? "propertychange" : evt)] = fn;
}
},
fnGet: function (url, fn, timeout) {
var xhr = null;
try {
if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
} else if (Window.ActiveXObject) {
xhr = new ActiveXObject("Msxml2.Xmlhttp");
}
} catch (e) {
//TODO handle the exception
xhr = new ActiveXObject('Microsoft.Xmlhttp');
}
xhr.onreadystatechange = function () {
if (this.readyState == 4 && this.status == 200) {
fn.call(this, this.responseText);
} else {
setTimeout(function () {
xhr.abort();
}, timeout);
}
};
xhr.open('get', url, true);
xhr.send();
}
}
}
window.AutoComplete = function (option) {
var aOption = Array.prototype.slice.call(arguments);
for(var i=0;i<aOption.length;i++){
var autoComplete = new AutoComplete();
autoComplete.fnInit(aOption[i]);
autoComplete.fnRender();
}
}
})(window);
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div>
<input type="text" id="txtTest">
</div>
<br>
<div>
<input type="text" id="txtTest1">
</div>
<script src="autoComplete.js"></script>
<script>
window.onload = function () {
var option = {
id: 'txtTest', //控件id
data: [{
"id": "1",
"name": "aaaaa"
}, {
"id": "2",
"name": "bbbbb"
}, {
"id": "2",
"name": "bbb吴bb"
}, {
"id": "2",
"name": "bbbzbb"
}],
paraName: 'name',
textFiled: 'name', //显示的文字的属性名
valueFiled: 'id', //获取value的属性名
select: function (val, text) {
alert(val + '' + text);
} //选择选项时触发的事件
};
var option1 = {
id: 'txtTest1', //控件id
url: 'data.json', //数据
paraName: 'name',
textFiled: 'name', //显示的文字的属性名
valueFiled: 'id', //获取value的属性名
select: function (val, text) {
alert(val + '' + text);
} //选择选项时触发的事件
};
AutoComplete(option,option1);
}
</script>
</body>
</html>
data.json
[
{
"id": "1",
"name": "aaaaa"
},
{
"id": "2",
"name": "bbbbb"
},
{
"id": "3",
"name": "ccccc"
}
]
以上就是本文的全部内容，希望对大家学习javascript程序设计有所帮助。