客户端和服务器端信用卡验证...(我的简单方法系列文章)

引言

使用正则表达式进行信用卡验证。

背景

你需要具备正则表达式的一些知识，因为这是此功能的核心部分。

使用代码

不用担心，代码很简单，你只要看一眼就能理解...

//

// first Client side validation using JavaScript...

// you have to put to controls one is drop down list (for different credit 

//cards names)and other is textbox (for card number).

//just pass two parameter to this function one is id of dropdownlist and 

//textbox.

function ValidateCC(CCType, CCNum)
 {        
        var cctype= document.getElementById(CCType);                                                
        var ccnum= document.getElementById(CCNum);
       
        var validCCNum=false;
        var validCC=false;
        
        if(ccnum.value == "")
        {      
            return false;   
        }
        
        validCC= isValidCreditCard
        (cctype.options[cctype.selectedIndex].value,ccnum.value);
        if( validCC)
        {  
            return true;                             
        }                               
       
        return false;                                                                                                                
                            
 }
// this function is calling another function isValidCreditCard 

//for number validation and it is here...

function isValidCreditCard(type, ccnum) 
           {                                        
            if (type == "Visa")                                                
               var re = /^[4]([0-9]{15}$|[0-9]{12}$)/;                    
            else if (type == "MasterCard")                                                    
               var re = /^[5][1-5][0-9]{14}$/;                        
            else if (type == "Discover")                                                   
               var re = /^6011-?\d{4}-?\d{4}-?\d{4}$/;
            else if (type == "Diners Club") 
               var re = /(^30[0-5][0-9]{11}$)|(^(36|38)[0-9]{12}$)/;
            else if (type == "American Express") 
               var re = /^[34|37][0-9]{14}$/;     
            else if (type == "enRoute") 
               var re = /^(2014|2149)[0-9]{11}$/;                        
            else if (type == "JCB") 
               var re = /(^3[0-9]{15}$)|(^(2131|1800)[0-9]{11}$)/;
                                       
            if (!re.test(ccnum)) 
                  return false;
                       
            ccnum = ccnum.split("-").join("");
                       
            var checksum = 0;
            for (var i=(2-(ccnum.length % 2)); i<=ccnum.length; i+=2) 
            {
                 checksum += parseInt(ccnum.charAt(i-1));                           
            }
                       
            for (var i=(ccnum.length % 2) + 1; i<ccnum.length; i+=2) {
                   var digit = parseInt(ccnum.charAt(i-1)) * 2;
                   if (digit < 10) 
                     { checksum += digit; } 
                   else 
                     { checksum += (digit-9);}
            }
            if ((checksum % 10) == 0)
            {                           
                return true;
            }
            else 
                return false;
           }
 
//now at the server side in asp.net with c#...

private bool checkCCValidation()
        {            
            bool validCC = false;
            
            if(txtCCNumber.Text == "")
            {                
                return false;   
            }
            
     validCC= isValidCreditCard(selectCCType.Value,txtCCNumber.Text.Trim());
            if( validCC)
            {  
                return true;                             
            }                               
            
            return false;                                                                                                                 
           
        }
//this method is also calling another method and it is here..

private bool isValidCreditCard(string type, string ccnum) 
           {
                string regExp = "";
                                                
                if (type == "Visa")                                                
                    regExp = "^[4]([0-9]{15}$|[0-9]{12}$)";
                else if (type == "MasterCard")                                                    
                    regExp = "^[5][1-5][0-9]{14}$";                        
                else if (type == "Discover")                                                   
                    regExp = "^6011-?\\d{4}-?\\d{4}-?\\d{4}$";
                else if (type == "Diners Club") 
                     regExp = "(^30[0-5][0-9]{11}$)|(^(36|38)[0-9]{12}$)";
                else if (type == "American Express") 
                     regExp = "^[34|37][0-9]{14}$";     
                else if (type == "enRoute") 
                     regExp = "^(2014|2149)[0-9]{11}$";                        
                else if (type == "JCB") 
                     regExp = "(^3[0-9]{15}$)|(^(2131|1800)[0-9]{11}$)";

                 if (!Regex.IsMatch(ccnum,regExp)) 
                    return false;

                string[] tempNo = ccnum.Split('-');
                ccnum = String.Join("", tempNo);
               
                int checksum = 0;
             for (int i = (2-(ccnum.Length % 2)); i <= ccnum.Length; i += 2) 
                {
                    checksum += Convert.ToInt32(ccnum[i-1].ToString());
                }

                int digit = 0;
             for (int i = (ccnum.Length % 2) + 1; i < ccnum.Length; i += 2)
                {
                    digit = 0;
                    digit = Convert.ToInt32(ccnum[i-1].ToString()) * 2;
                    if (digit < 10)
                    { checksum += digit; }
                    else
                    { checksum += (digit - 9); }
                }
                if ((checksum % 10) == 0)
                    return true;
                else 
                    return false;

           }
 
//so that is the end of simple way of validating credit card, without using 

//any third party controls..so enjoy...

请记得使用语言下拉菜单设置代码片段的语言。

使用“var”按钮将变量或类名包裹在标签中，例如this。

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