收藏的几个js方法

  1 
  2  // 说明：用 Javascript 获取指定页面元素的位置 
  3 function getElementPos(elementId) {
  4     var ua = navigator.userAgent.toLowerCase();
  5     var isOpera = (ua.indexOf('opera') != -1);
  6     var isIE = (ua.indexOf('msie') != -1 && !isOpera); // not opera spoof 
  7     var el = document.getElementById(elementId);
  8     if (el.parentNode === null || el.style.display == 'none') {
  9         return false;
 10     }
 11     var parent = null;
 12     var pos = [];
 13     var box;
 14     if (el.getBoundingClientRect)    //IE 
 15     {
 16         box = el.getBoundingClientRect();
 17         var scrollTop = Math.max(document.documentElement.scrollTop, document.body.scrollTop);
 18         var scrollLeft = Math.max(document.documentElement.scrollLeft, document.body.scrollLeft);
 19         return { x: box.left + scrollLeft, y: box.top + scrollTop };
 20     }
 21     else if (document.getBoxObjectFor)    // gecko 
 22     {
 23         box = document.getBoxObjectFor(el);
 24         var borderLeft = (el.style.borderLeftWidth) ? parseInt(el.style.borderLeftWidth) : 0;
 25         var borderTop = (el.style.borderTopWidth) ? parseInt(el.style.borderTopWidth) : 0;
 26         pos = [box.x - borderLeft, box.y - borderTop];
 27     }
 28     else    // safari & opera 
 29     {
 30         pos = [el.offsetLeft, el.offsetTop];
 31         parent = el.offsetParent;
 32         if (parent != el) {
 33             while (parent) {
 34                 pos[0] += parent.offsetLeft;
 35                 pos[1] += parent.offsetTop;
 36                 parent = parent.offsetParent;
 37             }
 38         }
 39         if (ua.indexOf('opera') != -1
 40     || (ua.indexOf('safari') != -1 && el.style.position == 'absolute')) {
 41             pos[0] -= document.body.offsetLeft;
 42             pos[1] -= document.body.offsetTop;
 43         }
 44     }
 45     if (el.parentNode) { parent = el.parentNode; }
 46     else { parent = null; }
 47     while (parent && parent.tagName != 'BODY' && parent.tagName != 'HTML') { // account for any scrolled ancestors 
 48         pos[0] -= parent.scrollLeft;
 49         pos[1] -= parent.scrollTop;
 50         if (parent.parentNode) { parent = parent.parentNode; }
 51         else { parent = null; }
 52     }
 53     return { x: pos[0], y: pos[1] };
 54 }
 55 
 56 function $(objid) { return document.getElementById(objid); }
 57 
 58 String.prototype.Trim = function () { return this.replace(/(^\s*)|(\s*$)/g, ""); }
 59 String.prototype.LTrim = function () { return this.replace(/(^\s*)/g, ""); }
 60 String.prototype.RTrim = function () { return this.replace(/(\s*$)/g, ""); }
 61 
 62 String.prototype.endWith = function (str) {
 63     if (str == null || str == "" || this.length == 0 || str.length > this.length)
 64         return false;
 65     if (this.substring(this.length - str.length) == str)
 66         return true;
 67     else
 68         return false;
 69     return true;
 70 }
 71 
 72 String.prototype.startWith = function (str) {
 73     if (str == null || str == "" || this.length == 0 || str.length > this.length)
 74         return false;
 75     if (this.substr(0, str.length) == str)
 76         return true;
 77     else
 78         return false;
 79     return true;
 80 }
 81 
 82 function contains(string, substr, isIgnoreCase) {
 83     if (isIgnoreCase) {
 84         string = string.toLowerCase();
 85         substr = substr.toLowerCase();
 86     }
 87     var startChar = substr.substring(0, 1);
 88     var strLen = substr.length;
 89     for (var j = 0; j < string.length - strLen + 1; j++) {
 90         if (string.charAt(j) == startChar)//如果匹配起始字符,开始查找
 91         {
 92             if (string.substring(j, j + strLen) == substr)//如果从j开始的字符与str匹配，那ok
 93             {
 94                 return true;
 95             }
 96         }
 97     }
 98     return false;
 99 }
100 
101 
102 //----------------------------- 判断浏览器 -------------------------
103 function myBrowser() {
104     var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串
105     var isOpera = userAgent.indexOf("Opera") > -1; //判断是否Opera浏览器
106     var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1 && !isOpera; //判断是否IE浏览器
107     var isFF = userAgent.indexOf("Firefox") > -1; //判断是否Firefox浏览器
108     var isSafari = userAgent.indexOf("Safari") > -1 && userAgent.indexOf("Chrome") < 1; //判断是否Safari浏览器
109     var isChrome = userAgent.indexOf("Chrome") > -1; //判断是否Chrome浏览器
110     if (isIE) {
111         var IE5 = IE55 = IE6 = IE7 = IE8 = false;
112         var reIE = new RegExp("MSIE (\\d+\\.\\d+);");
113         reIE.test(userAgent);
114         var fIEVersion = parseFloat(RegExp["$1"]);
115         IE55 = fIEVersion == 5.5;
116         IE6 = fIEVersion == 6.0;
117         IE7 = fIEVersion == 7.0;
118         IE8 = fIEVersion == 8.0;
119         if (IE55) { return "IE55"; }
120         if (IE6) { return "IE6"; }
121         if (IE7) { return "IE7"; }
122         if (IE8) { return "IE8"; }
123     }
124     if (isFF) { return "FF"; }
125     if (isOpera) { return "Opera"; }
126     if (isSafari) { return "Safari"; }
127     if (isChrome) { return "Chrome"; }
128 } 
129 

 

新增加：获取参数方法

// 说明：Javascript 获取链接(url)参数的方法 
function getQueryString(name) {     // 如果链接没有参数，或者链接中不存在我们要获取的参数，直接返回空     
    if (location.href.indexOf("?") == -1 || location.href.indexOf(name + '=') == -1)
    { return ''; }
    // 获取链接中参数部分 
    var queryString = location.href.substring(location.href.indexOf("?") + 1);
    // 分离参数对 ?key=value&key2=value2 
    var parameters = queryString.split("&");
    var pos, paraName, paraValue;
    for (var i = 0; i < parameters.length; i++) {
        // 获取等号位置   
        pos = parameters[i].indexOf('=');
        if (pos == -1) { continue; }
        // 获取name 和 value 
        paraName = parameters[i].substring(0, pos);
        paraValue = parameters[i].substring(pos + 1);
        // 如果查询的name等于当前name，就返回当前值，同时，将链接中的+号还原成空格 
        if (paraName == name) {
            return unescape(paraValue.replace(/\+/g, " "));
        } 
    }
    return '';
};