常用正则

var regex = /^[\u4e00-\u9fa5\w]{4,12}$/; 
//昵称长度在4-12个字节之间，由中文，英文字母、数字和下划线组成
var regex = /^(((13[0-9]{1})|(15[0-9]{1})|(18[0-9]{1}))+\d{8})$/;    //请输入有效的手机号码
//手机
var pp=/^(13[0-9]|15[0|3|6|7|8|9]|18[0-9])\d{8}$/;
//电话
var reTel=/^([\+][0-9]{1,3}[ \.\-])?([\(]{1}[0-9]{2,6}[\)])?([0-9 \.\-\/]{3,20})((x|ext|extension)[ ]?[0-9]{1,4})?$/;
//邮箱
var reMail=/^([A-Za-z0-9_\-\.\'])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,6})$/;
//邮政编码
var zipCode=/^[1-9][0-9]{5}$/;

 

var lenReg = function(str){

    return str.replace(/[^\x00-\xFF]/g,'**').length;

};//判断是否是Email
                function isEmail(str) {
                    var regu = "^(([0-9a-zA-Z]+)|([0-9a-zA-Z]+[_.0-9a-zA-Z-]*))@([a-zA-Z0-9-]+[.])+([a-zA-Z]{2}|net|com|gov|mil|org|edu|int|name|asia)$";
                    var re = new RegExp(regu);
                    if (str.search(re) == -1) {
                        return false;
                    }
                    else {
                        return true;
                    }
                }

 

var regNum2 = /^(([1-9]\d*)|0)(\.\d{1,2})?$/;
        $.validator.addMethod(
        "num2_validate",
        function(value, element) {
            return regNum2.test($.trim(value));
        },
        "确保为非负数且最多只能有两位小数"
    ); 

 

//身份证
function v_id(){
    var cVal = $.trim($("#txtId").val());
    var _ts = $("#ts_ID");
    _ts.css("color", "red");
    var pattern;
    if (cVal.length == 15) {
        pattern = /^\d{15}$/;//正则表达式,15位且全是数字
        if (pattern.exec(cVal) == null) {
            _ts.html("身份证格式不正确");
            return false;
        }
        if (!isdate("19" + cVal.substring(6, 8), cVal.substring(8, 10), cVal.substring(10, 12))) {
            _ts.html("身份证格式不正确");
            return false;
        }
        
    }
    else if (cVal.length == 18) {
        pattern = /^\d{17}(\d|x|X)$/;//正则表达式,18位且前17位全是数字，最后一位只能数字,x,X
        if (pattern.exec(cVal) == null) {
            _ts.html("身份证格式不正确");
            return false;
        }
        if (!isdate(cVal.substring(6, 10), cVal.substring(10, 12), cVal.substring(12, 14))) {
            _ts.html("身份证格式不正确");
            return false;
        }
        var strJiaoYan = ["1", "0", "X", "9", "8", "7", "6", "5", "4", "3", "2"];
        var intQuan = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2, 1];
        var intTemp = 0;
        for (i = 0; i < cVal.length - 1; i++)
            intTemp += cVal.substring(i, i + 1) * intQuan[i];
        intTemp %= 11;
        if (cVal.substring(cVal.length - 1, cVal.length).toUpperCase() != strJiaoYan[intTemp]) {
            _ts.html("身份证格式不正确");
            return false;
        }
    }
    else {
        _ts.html("身份证格式不正确");
        return false;
    }
    _ts.html("");
    return true;
}
//检查年月日是否是合法日期
function isdate(intYear, intMonth, intDay){
    if (isNaN(intYear) || isNaN(intMonth) || isNaN(intDay))
        return false;
    if (intMonth > 12 || intMonth < 1)
        return false;
    if (intDay < 1 || intDay > 31)
        return false;
    if ((intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11) && (intDay > 30))
        return false;
    if (intMonth == 2) {
        if (intDay > 29)
            return false;
        if ((((intYear % 100 == 0) && (intYear % 400 != 0)) || (intYear % 4 != 0)) && (intDay > 28))
            return false;
    }
    return true;
}

string yourhtml = @"<img alt= ""test"" alt=network-adaptors.jpg src= ""http://www.sinaimg.cn/IT/cr/2007/0704/3441139462.jpg "" style= ""border:0px solid #000; "" _extended= ""true "">  
<img alt= ""test"" alt=network-adaptors.jpg src= ""http://www.sinaimg.cn/IT/cr/2008/34/3656462.jpg "" style= ""border:0px solid #000; "" _extended= ""true "">  ";
        string str = "指定的路径/";
        yourhtml = System.Text.RegularExpressions.Regex.Replace(yourhtml, @"(?i)(?<=<img\b[^>]*?src=\s*(['""]?))([^'""]*/)+(?=[^'""/]+\1)", str);