Chức năng: Tích hợp thanh toán qua Ngân lượng

using System; 
using System.Configuration; 
using System.Data; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.HtmlControls; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Xml.Linq; 
using System.Collections; 
public class NL_Checkout 
{ 

private String nganluong_url = "http://sandbox.nganluong.vn/checkout.php"; 
private String merchant_site_code = "275";    //thay ma merchant site ma ban da dang ky vao day 
private String secure_pass = "123456";    //thay mat khau giao tiep giua website cua ban voi NganLuong.vn ma ban da dang ky vao day 

public String GetMD5Hash(String input) 
{ 

System.Security.Cryptography.MD5CryptoServiceProvider x = new System.Security.Cryptography.MD5CryptoServiceProvider(); 

byte[] bs = System.Text.Encoding.UTF8.GetBytes(input); 

bs = x.ComputeHash(bs); 

System.Text.StringBuilder s = new System.Text.StringBuilder(); 

foreach (byte b in bs) 
{ 
s.Append(b.ToString("x2").ToLower()); 
} 
String md5String = s.ToString(); 
return md5String; 
} 

public String buildCheckoutUrl(String return_url, String receiver, String transaction_info, String order_code, String price) 
{ 
// Tạo biến secure code 
String secure_code = ""; 

secure_code += this.merchant_site_code; 

secure_code += " " + HttpUtility.UrlEncode(return_url).ToLower(); 

secure_code += " " + receiver; 

secure_code += " " + transaction_info; 

secure_code += " " + order_code; 

secure_code += " " + price; 

secure_code += " " + this.secure_pass; 

// Tạo mảng băm 
Hashtable ht = new Hashtable(); 

ht.Add("merchant_site_code", this.merchant_site_code); 

ht.Add("return_url", HttpUtility.UrlEncode(return_url).ToLower()); 

ht.Add("receiver", receiver); 

ht.Add("transaction_info", transaction_info); 

ht.Add("order_code", order_code); 

ht.Add("price", price); 

ht.Add("secure_code", this.GetMD5Hash(secure_code)); 

// Tạo url redirect 
String redirect_url = this.nganluong_url; 

if (redirect_url.IndexOf("?") == -1) 
{ 
redirect_url += "?"; 
} 
else if (redirect_url.Substring(redirect_url.Length - 1, 1) != "?" && redirect_url.IndexOf("&") == -1) 
{ 
redirect_url += "&"; 
} 

String url = ""; 

// Duyêt các phần tử trong mảng băm ht dể tạo redirect url 
IDictionaryEnumerator en = ht.GetEnumerator(); 

while (en.MoveNext()) 
{ 
if (url == "") 
url += en.Key.ToString() + "=" + en.Value.ToString(); 
else 
url += "&" + en.Key.ToString() + "=" + en.Value; 
} 

String rdu = redirect_url + url; 

return rdu; 
} 

public Boolean verifyPaymentUrl(String transaction_info, String order_code, String price, String payment_id, String payment_type, String error_text, String secure_code) 
{ 
// Tạo mã xác thực từ web 
String str = ""; 

str += " " + transaction_info; 

str += " " + order_code; 

str += " " + price; 

str += " " + payment_id; 

str += " " + payment_type; 

str += " " + error_text; 

str += " " + this.merchant_site_code; 

str += " " + this.secure_pass; 

// Mã hóa các tham số
String verify_secure_code = ""; 

verify_secure_code = this.GetMD5Hash(str); 

// Xác thực mã của web với mã trả về từ nganluong.vn 
if (verify_secure_code == secure_code) return true; 

return false; 
} 
}

protected void btnSubmit_Click(object sender, EventArgs e) 
{ 
String return_url = "http://localhost:35921/WebSite/"; 
String transaction_info = "DEMO"; 
String order_code = DateTime.Now.ToString("yyyyMMddHHmmss"); 
String receiver = "webmaster@dotnet.vn";//Tài khoản nhận tiền 
String price = "100000"; 
NL_Checkout nl = new NL_Checkout(); 
String url; 
url = nl.buildCheckoutUrl(return_url, receiver, transaction_info, order_code, price); 
Response.Redirect(url); 
}