JavaScript常用方法

手机类型判断

var ua = navigator.userAgent.toLowerCase(),
      BrowserInfo = {    
    // 安卓
    isAndroid: Boolean(ua.match(/android/g)),
   // iphone手机
    isIphone: Boolean(ua.match(/iphone|ipod/g)),
   // ipad
    isIpad: Boolean(ua.match(/ipad/g)),
   // 微信
    isWeixin: Boolean(ua.match(/MicroMessenger/g)),
}

返回字符串长度，汉子计数为2

function strLength(str) { 
    var a = 0;            
    for (var i = 0; i < str.length; i++) {
    if (str.charCodeAt(i) > 255)
        a += 2;//按照预期计数增加2
    else
        a++;
    }
    return a;
 }

获取url中的参数

    /**
     * 公共方法定义
     * @example: http://xxx.com/a.do?name=zhangsan
     *     输出:  getParameter('name')  // 'zhangsan'
     */
    var getParameter = function(param, url) {
        var reg = new RegExp('[&,?,&]' + param + '=([^\\&]*)', 'i'),
              value = reg.exec(decodeURIComponent(decodeURIComponent(url || location.search || location.hash)));
        return value ? value[1] : '';
    }

js 绑定事件 适用于任何浏览器的元素绑定

function eventBind(obj, eventType, callBack) {
   // w3c
    if (obj.addEventListener) {
        obj.addEventListener(eventType, callBack, false);
    // 低版本ie
    }else if (window.attachEvent) {
        obj.attachEvent('on' + eventType, callBack);
    }else {
        obj['on' + eventType] = callBack;
    }
};
eventBind(document, 'click', bodyClick);

移除事件

this.moveBind = function (objId, eventType, callBack) {
    var obj = document.getElementById(objId);
    if (obj.removeEventListener) {
        obj.removeEventListener(eventType, callBack, false);
    }else if (window.detachEvent) {
        obj.detachEvent('on' + eventType, callBack);
    }else {
        obj['on' + eventType] = null;
    }
}

获取当前点击事件的Object对象

function getEvent() {    
    if (document.all) {        
    return window.event; //如果是ie
    }
    func = getEvent.caller;    
    while (func != null) {        
    var arg0 = func.arguments[0];        
    if (arg0) {            
    if ((arg0.constructor == Event || arg0.constructor == MouseEvent)
|| (typeof (arg0) == "object" && arg0.preventDefault && arg0.stopPropagation)) {
            return arg0;
            }
        }
        func = func.caller;
    }    
    return null;
};

字符串截取方法

var getCharactersLen = function (charStr, cutCount) {
    if (charStr == null || charStr == '') 
    return '';        
    var totalCount = 0;        
    var newStr = '';        
    for (var i = 0; i < charStr.length; i++) {            
    var c = charStr.charCodeAt(i);            
    if (c < 255 && c > 0) {
        totalCount++;
    } else {
        totalCount += 2;
    } 
    if (totalCount >= cutCount) {
        newStr += charStr.charAt(i);
        break;
    }else {
        newStr += charStr.charAt(i);
        }
   }        
   return newStr;
}

js 判断浏览器

判断是否是 IE 浏览器

if (document.all || !!window.ActiveXObject){ 
    alert(”IE浏览器”); 
}else{ 
    alert(”非IE浏览器”); 
} 

判断是IE几

var isIE=!!window.ActiveXObject; 
var isIE6=isIE&&!window.XMLHttpRequest; 
var isIE8=isIE&&!!document.documentMode; 
var isIE7=isIE&&!isIE6&&!isIE8; 
if (isIE){ 
    if (isIE6){ 
        alert(”ie6″); 
    }else if (isIE8){ 
        alert(”ie8″); 
    }else if (isIE7){ 
        alert(”ie7″); 
    } 
}

判断浏览器

function getOs() {   
    var ua = navigator.userAgent；
    if (ua.indexOf("MSIE 8.0") > 0) {        
        return "MSIE8";
    }else if (ua.indexOf("MSIE 6.0") > 0) {
        return "MSIE6";
    }else if (ua.indexOf("MSIE 7.0") > 0) {
        return "MSIE7";
    }else if (isFirefox = ua.indexOf("Firefox") > 0) {
        return "Firefox";
    }
    if (ua.indexOf("Chrome") > 0) {
        return "Chrome";
    }else {
        return "Other";
    }
}

JS判断两个日期大小

//得到日期值并转化成日期格式
//replace(/\-/g, "\/")是根据验证表达式把日期转化成长日期格式
//这样再进行判断就好判断了
function ValidateDate(beginDate,endDate) {
    if (beginDate.length > 0 && endDate.length>0) {
        var sDate = new Date(beginDate.replace(/\-/g, "\/"));                
        var eDate= new Date(endDate.replace(/\-/g, "\/"));                
        if (sDate > eDate) {
            // 开始日期要小于结束日期
            return false;
        }
        return true;
    }
}

回车提交

document.getElementById("id").onkeypress = function (event) {    
    event = (event) ? event : ((window.event) ? window.event : "")
    keyCode = event.keyCode ? event.keyCode : (event.which ? event.which : event.charCode);    
    if (keyCode == 13) {
        // 提交操作
    }
}

JS 写Cookie

function setCookie(name, value, expires, path, domain) {
    if (!expires) 
    expires = -1;
    if (!path) 
    path = "/";
    var d = "" + name + "=" + value;
    var e;
    if (expires < 0) {
        e = "";
    }else if (expires == 0) {
        var f = new Date(1970, 1, 1);
        e = ";expires=" + f.toUTCString();
    }else {
        var now = new Date();
        var f = new Date(now.getTime() + expires * 1000);
        e = ";expires=" + f.toUTCString();
    }
    var dm;
    if (!domain) {
        dm = "";
    }else {
        dm = ";domain=" + domain;
    }
    document.cookie = name + "=" + value + ";path=" + path + e + dm;
};

JS 读Cookie

function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') c = c.substring(1, c.length);
        if (c.indexOf(nameEQ) == 0) {
            return decodeURIComponent(c.substring(nameEQ.length, c.length))
        }
    } 
    return null
}

Ajax 请求

var ajax = function (args) {    
    var self = this;
    this.options = {
        type: 'GET',
        async: true,
        contentType: 'application/x-www-form-urlencoded',
        url: 'about:blank',
        data: null,
        success: {},
        error: {}
    };
    this.getXmlHttp = function () {
    var xmlHttp;
    try {
        xmlhttp = new XMLHttpRequest();
    }catch (e) {
        try {
            xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
        }catch (e) {
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }if (!xmlhttp) {
        alert('您的浏览器不支持AJAX');
        return false;
    }
        return xmlhttp;
    };
    this.send = function () {
    C.each(self.options, function (key, val) {
    self.options[key] = (args[key] == null) ? val : args[key];
    });
    var xmlHttp = new self.getXmlHttp();
    if (self.options.type.toUpperCase() == 'GET') {
        xmlHttp.open(self.options.type, self.options.url + (self.options.data == null ? "" : ((/[?]$/.test(self.options.url) ? '&' : '?') + self.options.data)), self.options.async);
    }else {
        xmlHttp.open(self.options.type, self.options.url, self.options.async);
        xmlHttp.setRequestHeader('Content-Length', self.options.data.length);
    }
        xmlHttp.setRequestHeader('Content-Type', self.options.contentType);
        xmlHttp.onreadystatechange = function () {
        if (xmlHttp.readyState == 4) {
        if (xmlHttp.status == 200 || xmlHttp.status == 0) {                    if (typeof self.options.success == 'function') self.options.success(xmlHttp.responseText);
            xmlHttp = null;
        }else {
        if (typeof self.options.error == 'function') 
        self.options.error('Server Status: ' + xmlHttp.status);
                }
            }
        };
        xmlHttp.send(self.options.type.toUpperCase() == 'POST' ? self.options.data.toString() : null);
    };
    this.send();
};

JS StringBuilder 用法

function StringBuilder() {
this.strings = new Array;
};
StringBuilder.prototype.append = function (str) {
this.strings.push(str);
};
StringBuilder.prototype.toString = function () {
return this.strings.join('');
};

JS 替换非法字符主要用在密码验证上出现的特殊字符

function URLencode(sStr) {
     return escape(sStr).replace(/\+/g, '%2B').replace(/\"/g, '%22').replace(/\'/g, '%27').replace(/\//g, '%2F');
};

按Ctrl + Entert 直接提交表单

document.body.onkeydown = function (evt) {
        evt = evt ? evt : (window.event ? window.event : null);
        if (13 == evt.keyCode && evt.ctrlKey) {
            evt.returnValue = false;
            evt.cancel = true;
            PostData();
        }
};

Js 去掉空格方法

String.prototype.Trim = function(){ 
    return this.replace(/(^\s*)|(\s*$)/g, ""); 
    }
String.prototype.LTrim = function(){
    return this.replace(/(^\s*)/g, "");
    }
String.prototype.RTrim = function(){
    return this.replace(/(\s*$)/g, "");
    }