它現在這種支付方式比較多象網銀在線等使用的方法都是url驗證，就是通過url參數和一個這些url參數的md5編碼來確認這個連接的正確性，支付寶在你購買成功后跳轉自定義連接的時候會傳2次過來，第一次是數據底層請求，第二次是web請求，而只有第一次有驗證碼，這個只能通過記錄下來才看的到，因為兩次請求間隔很小，如果光顯示的話最后的結果是被第二次覆蓋了的。所以在接收的時候就要設定接收條件，一種是沒有notify_type參數的，一種是有的。
我們先來看一下創建一個連接地址
t1=ConfigurationSettings.AppSettings["interface"];//支付接口，就是給的一個連接地址
t2=ConfigurationSettings.AppSettings["account"];//支付寶帳戶你的帳戶
t3=ConfigurationSettings.AppSettings["password"];//安全校驗碼，設置的商家驗證碼
t4="images/logo_zfbsmall.gif";//按鈕圖片地址
t5="test";//懸停說明
cmd="0001";//默認
subject="item";//商品名稱
body="decrip";//描述
order_no=;//定單號，用戶自己生成，方便自己管理 prices=100;//價格0.01～50000.00
rurl="商品展示網址
types="1";//1：商品購買2：服務購買3：網絡拍賣4：捐贈
number="1";//購買數量
transport="3";//1：平郵2：快遞3：虛擬物品
ordinary_fee="";//平郵運費
express_fee="";//快遞運費
readonlys="true";//交易信息是否只讀
buyer_msg="";//買家給賣家的留言
buyer="";//買家Email
buyer_name="";//買家姓名
buyer_address="";//買家地址
buyer_zipcode="";//買家郵編
buyer_tel="";//買家電話號碼
buyer_mobile="";//買家手機號碼
partner=ConfigurationSettings.AppSettings["partenid"];//合作伙伴ID，這個是固定的
上面就是要提供得基本信息，然后就是生成支付寶得連接，也就是給支付寶提供一條帶驗證的購買信息。
public string creatAlipayItemURL(string t1，string t2，string t3，string t4，string t5，string cmd，string subject，string body，string order_no，string prices，string rurl，string types，string number，string transport，string ordinary_fee，string express_fee，string readonlys，string buyer_msg，string buyer，string buyer_name，string buyer_address，string buyer_zipcode，string buyer_tel，string buyer_mobile，string partner)
{
string itemURL，str2CreateAc，acCode;
string INTERFACE_URL，sellerEmail，keyCode，imgsrc，imgtitle，AlipayItemURL;
//初始化各必要變量
INTERFACE_URL=t1+t2;//支付接口
sellerEmail=t2;//商戶支付寶賬戶(改成你自己的)
keyCode=t3;//安全校驗碼(改成你自己的)
imgsrc=t4;//支付寶按鈕圖片
imgtitle=t5;//按鈕懸停說明
str2CreateAc="cmd" + cmd + "subject" + subject;
str2CreateAc=str2CreateAc + "body" + body;
str2CreateAc=str2CreateAc + "order_no" + order_no;
str2CreateAc=str2CreateAc + "price" + prices;
//str2CreateAc=str2CreateAc + "url" + rurl;
str2CreateAc=str2CreateAc + "type" + types;
str2CreateAc=str2CreateAc + "number" + number;
str2CreateAc=str2CreateAc + "transport" + transport;
/*str2CreateAc=str2CreateAc + "ordinary_fee" + ordinary_fee;
str2CreateAc=str2CreateAc + "express_fee" + express_fee;
str2CreateAc=str2CreateAc + "readonly" + readonlys;
str2CreateAc=str2CreateAc + "buyer_msg" + buyer_msg;*/
str2CreateAc=str2CreateAc + "seller" + sellerEmail;
/*str2CreateAc=str2CreateAc + "buyer" + buyer;
str2CreateAc=str2CreateAc + "buyer_name" + buyer_name;
str2CreateAc=str2CreateAc + "buyer_address" + buyer_address;
str2CreateAc=str2CreateAc + "buyer_zipcode" + buyer_zipcode;
str2CreateAc=str2CreateAc + "buyer_tel" + buyer_tel;
str2CreateAc=str2CreateAc + "buyer_mobile" + buyer_mobile;*/
str2CreateAc=str2CreateAc + "partner" + partner;
str2CreateAc=str2CreateAc + keyCode;
//acCode=FormsAuthentication.HashPasswordForStoringInConfigFile(str2CreateAc，"MD5");
acCode=this.GetMD5(str2CreateAc，"gb2312");
itemURL=INTERFACE_URL + "？cmd=" + cmd;
itemURL=itemURL + "&subject=" + HttpUtility.UrlEncode(subject);
itemURL=itemURL + "&body=" + HttpUtility.UrlEncode(body);
itemURL=itemURL + "&order_no=" + order_no;
itemURL=itemURL + "&price=" + prices;
//itemURL=itemURL + "&url=" + rurl;
itemURL=itemURL + "&type=" + types;
itemURL=itemURL + "&number=" + number;
itemURL=itemURL + "&transport=" + transport;
/*itemURL=itemURL + "&ordinary_fee=" + ordinary_fee;
itemURL=itemURL + "&express_fee=" + express_fee;
itemURL=itemURL + "&readonly=" + readonlys;
itemURL=itemURL + "&buyer_msg=" + HttpUtility.UrlEncode(buyer_msg);
itemURL=itemURL + "&buyer=" + HttpUtility.UrlEncode(buyer);
itemURL=itemURL + "&buyer_name=" + HttpUtility.UrlEncode(buyer_name);
itemURL=itemURL + "&buyer_address=" + HttpUtility.UrlEncode(buyer_address);
itemURL=itemURL + "&buyer_zipcode=" + buyer_zipcode;
itemURL=itemURL + "&buyer_tel=" + buyer_tel;
itemURL=itemURL + "&buyer_mobile=" + buyer_mobile;*/
itemURL=itemURL + "&partner=" + partner;
itemURL=itemURL + "&ac=" + acCode;
AlipayItemURL=itemURL;
return AlipayItemURL;
}
這個函數就是返回生成的地址，里面注釋掉的看你自己需要可以添加進去，然后就是md5碼的問題，現在用默認的md5生成程序對中文的支持只限于GB2312，而支付寶使用的是GBK，雖然兩個編碼的內容GBK兼容GB2312但是畢竟兩個編碼方式不同，所以會產生錯誤，如果用英文或者數字不會有問題。上面下載里面帶的一個md5.asp的算法支持中文。
現在已經可以跳轉到支付寶的頁面了，而我們這邊就要自己記錄用戶的信息已經生成的定單編號，這樣在支付寶返回信息的時候來查詢。在設定了返回地址后，我們就要看接收頁面了。
string msg_id，order_no，gross，buyer_email，buyer_name，buyer_address，buyer_zipcode，buyer_tel，buyer_mobile，action，s_date，ac，notify_type;
string returnTxt;//返回給支付寶通知接口的結果
string alipayNotifyURL;//支付寶查詢接口URL
string myalipayEmail;//商戶的支付寶Email
string ResponseTxt="";
returnTxt = "N";
alipayNotifyURL = ConfigurationSettings.AppSettings["interfaceback"];//支付寶查詢接口地址
myalipayEmail = ConfigurationSettings.AppSettings["account"];//填寫您的支付寶帳號
//檢查支付寶通知接口傳遞過來的參數是否合法
msg_id = newop.DelStr(Request["msg_id"]);
order_no = newop.DelStr(Request["order_no"]);
gross = newop.DelStr(Request["gross"]);
buyer_email = newop.DelStr(Request["buyer_email"]);
buyer_name = newop.DelStr(Request["buyer_name"]);
buyer_address = newop.DelStr(Request["buyer_address"]);
buyer_zipcode = newop.DelStr(Request["buyer_zipcode"]);
buyer_tel = newop.DelStr(Request["buyer_tel"]);
buyer_mobile = newop.DelStr(Request["buyer_mobile"]);
action = newop.DelStr(Request["action"]);
s_date = newop.DelStr(Request["date"]);
ac = newop.DelStr(Request["ac"]);
notify_type = newop.DelStr(Request["notify_type"]);
alipayNotifyURL = alipayNotifyURL + "msg_id=" + msg_id + "&email=" + myalipayEmail + "&order_no=" + order_no;
System.Net.WebClient isClient= new System.Net.WebClient();
Stream isStream = isClient.OpenRead(alipayNotifyURL);
StreamReader isReader = new StreamReader(isStream，System.Text.Encoding.GetEncoding("GB2312"));
ResponseTxt = isReader.ReadToEnd();
if(action == "test")//測試商戶網站URL是否正確安裝
{
returnTxt = "Y";
}
else if((action=="sendOff")&&(msg_id！=""))//發貨通知
{
returnTxt = "N";
if((ResponseTxt == "true")||(ResponseTxt == "false"))
{
//更新數據在商戶系統里的訂單數據;如果已經發貨，則將returnTxt置為Y，否則為N
}
else
{
//非法數據，不做更新
returnTxt="Error";
}
}
else if((action=="sendOff")&&(notify_type=="web"))
{
//檢查是否已經付帳，并記錄 }
else if((action=="checkOut")&&(msg_id！=""))//交易結束通知
{
returnTxt = "Y";
if((ResponseTxt=="true")||(ResponseTxt == "false"))
{
//更新數據在商戶系統里的訂單數據;如果數據更新成功，則將returnTxt置為Y，否則為N
//更新數據
//你的代碼，更新你這邊數據
returnTxt= "Y";
}
else
{
//非法數據，不做更新
returnTxt = "Error";
}
}
else
{
returnTxt="Error";
}
Response.Write(returnTxt);