解析javascript 实用函数的使用详解

function setHomepage(obj,url) {
// setHome(this, window.location)
    try {  
        obj.style.behavior = 'url(#default#homepage)';  
        obj.setHomePage(url);  
    } catch (e) {  
        if (window.netscape) {  
            try {  
                netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");  
            } catch (e) {  
                alert('此操作被浏览器拒绝！\n请在浏览器地址栏输入"about:config"并回车\n然后将 [signed.applets.codebase_principal_support]的值设置为"true",双击即可。');  
            }  
            var prefs = Components.classes['@mozilla.org/preferences-service;1'].getService(Components.interfaces.nsIPrefBranch);  
            prefs.setCharPref('browser.startup.homepage', vrl);  
        }  
    }  
}  

function boxMove(box){
//可移动的层
    var w = box.scrollWidth,h = box.scrollHeight;
    var iWidth = document.documentElement.clientWidth;
    var iHeight = document.documentElement.clientHeight;    
    var moveX = 0,moveY = 0,moveTop = 0,moveLeft = 0,moveable = false;
    box.onmousedown = function(e){   
    moveable = true;    
    e = window.event?window.event:e;
    moveX = e.clientX-box.offsetLeft;       
    moveY = e.clientY-box.offsetTop;
    box.style.zIndex++;
    }
    document.onmousemove = function(e){
        if(moveable){
            e = window.event?window.event:e;       
            var x = e.clientX - moveX;
            var y = e.clientY - moveY;
            if ( x > 0 &&( x + w < iWidth) && y > 0 && (y + h < iHeight)){
                box.style.left = x + "px";
                box.style.top = y + "px";
                box.style.margin = "auto";
            }
        }
    }
    document.onmouseup = function (){moveable = false;};
}

function getHtmlRoot(){
/*获得html文档的根元素*/
    if(document.compatMode.toLowerCase()=="css1compat"){
        htmlRoot = document.documentElement;
    }else{
        htmlRoot = document.body;
    }
    return htmlRoot;
}

function showWindow(boxId, closeId, showBg){//弹窗
    htmlRoot = getHtmlRoot();
    box = document.getElementById(boxId);
    boxId = '#' + boxId;
    closeId = '#' + closeId;
    showBox = $(boxId);
    showBox.show();
    z_index = 20;
    moveLeft =  (htmlRoot.clientWidth- box.clientWidth)/2 + htmlRoot.scrollLeft +'px';
    moveTop = (htmlRoot.clientHeight - box.clientHeight)/2 + htmlRoot.scrollTop;+'px';
    showBox.css({position:'absolute', left:moveLeft,zIndex:z_index, top:moveTop});

    boxMove(box);

    if(showBg){
        objMask = document.createElement("div");
        objMask.className = "BoxMask";
        htmlRoot.appendChild(objMask);
        objMask.style.cssText += 'position:absolute;top:0; left:0;filter:Alpha(Opacity=50);opacity:0.5;background:#AAA;';

        objMask.style.zIndex = z_index -1;
        objMask.style.width =  htmlRoot.clientWidth + 'px';
        objMask.style.height = htmlRoot.scrollHeight + htmlRoot.scrollTop + 'px';
    }

    $(closeId).click(function(){
        showBox.hide();
        mybg.style.display = "none";
    });
    $('.closeBtn').click = function(){
        showBox.hide();
        mybg.style.display = "none";   
    };

}

function getFormQuery(formId){
/*生成查询字串*/
    formObj = document.getElementById(formId);
       var i, queryString = "", and = "", itemValue;
       for(i = 0; i<formObj.length; i++ ){
             var item = formObj[i];
              if ( item.name!='' ){
                     if(item.type == 'select-one'){
                         itemValue = item.options[item.selectedIndex].value;
                     }else if ( item.type=='checkbox' || item.type=='radio'){
                         if ( item.checked == false ){ continue; }
                         itemValue = item.value;
                     }else if ( item.type == 'button' || item.type == 'submit' || item.type == 'reset' || item.type == 'image'){
                         continue;
                     }else{
                          itemValue = item.value;
                     }
                   //  itemValue = escape(itemValue);
                     queryString += and + item.name + '=' + itemValue;
                     and="&";
                   //queryString += and + encodeURIComponent(item.name) + '=' +encodeURIComponent( itemValue);
              }
       }
       return queryString;
}

//定义js错误处理函数
onerror = errHandle;
function errHandle(msg,url,line){
    var txt=""
    txt = "本页中有错误！\n\n"
    txt += "错误: "+ msg +"\n"
    txt += "地址: " + url + "\n"
    txt += "行数: " + line + "\n\n"
    alert(txt);
    return false;
}

function setAutoWidth(id,width,size){
//最小或最大宽度
    var obj = document.getElementById(id);
    if(size=='max'){
        obj.style.width = (obj.clientWidth > width) ? width + "px" : "auto";
    }else{
        obj.style.width = (obj.clientWidth < width) ? width + "px" : "auto";
    }
}

function fontScroll(id){
/*向左滚动的文字 */
    var obj = document.getElementById(id);
    var text = obj.innerHTML;
    var first = text.charAt(0);
    var left = text.substring(1, text.length);
    obj.inerHTML = left + first;
    //这个写函数之外 setInterval('fontScroll(id)', 500);
}

function bubbleSort(arr){
/*冒泡排序法*/
var sign = false // 初始化换位标记为假
for(var i=0; i < arr.length-1; i++){
    for(varj=0; j < arr.length-1-i; j++){
        if(arr[j]> arr[j+1]){
            vartemp = arr[j]
            arr[j]= arr[j+1]
            arr[j+1]= temp
            sign= true // 若当前这一圈比较中，有过换位，则置换位标记为真
        }
    }
    if(sign)// 判断当前这一圈有过换位否…
       sign= false // 有过换位，则重置换位标记为假
    else
       break// 没有，则终止
    }
return arr;
}

function getCoordinate(evt){
/*获得光标的坐标*/
    var x = evt.clientX;
    var y = evt.clientY;
    document.getElementById('show').innerHTML = x +' &' + y;
}

function checkEmail(email){
/*检测多个以分号(;)分隔的Email格式*/
if(email != null){
    if(email.indexOf(";",0) == -1){ //indexOf(被查找，起始位)返某个字符串在源字符串中首次出现的位置，失败返回-1
        if(!isEmail(email)){
            alert("单个邮件格式有误，请重输！");
            document.getElementById("email").focus();
            return false;
        }
    }else{
        var emailArr = email.split(";");//split(分隔段,数组总长度)字符串分割成字符串数组
        var i, iMax = emailArr.length;
        for(i = 0; i < iMax; i++){
            if(emailArr[i] != null || emailArr != ""){
                if(!isEmail(emailArr[i])){
                    alert("多个邮箱格式中有邮箱格式不正确，请重新核对后再输入!");   
                    document.getElementById("email").focus();
                    return false;
                }
            }
        }
    }   
}
function isEmail(str){
   var reg = /^(\w)+(\.\w+)*@(\w)+((\.\w+)+)$/;
   return reg.test(str);//test(被测字串)检测一个字符串是否匹配某个模式.
}
}