Xamarin只言片语3——Xamarin.Android下支付宝(Alipay SDK)使用

开发环境Visual Studio 2015,Xamarin 3.11.1537,Xamarin Android5.1.7.12

下载支付宝移动支付的SDK（http://doc.open.alipay.com/doc2/detail?treeId=54&articleId=103419&docType=1），找到Andriud的SDK，其中有一个alipaySDK-20151014.jar（这个版本，以后肯定会变化），这是我们使用的重点。

在Visual Studio中创建一个绑定库文件
把支付宝的alipaySDK-20151014.jar添加到Jars文件夹下，先中alipaySDK-20151014.jar，打开属性窗口，设置生成操作为EmbeddedJar，库文件搞定。
Android中使用绑定库文件
在Visual Studio中创建一个BlankApp应用，然后在打开项目属性，Android Manifest选项卡，在Required permissions中选择ACCESS_WIFI_STATE和INTERNET权限，添加绑定库生成的dll到当前项目的引用中。
添加签名生成类

using System;
using System.Text;
using System.IO;
using System.Security.Cryptography;
 
namespace App1
{
    class SignatureUtils
    {
        /// <summary>
        /// 签名
        /// </summary>
        /// <param name="content">需要签名的内容</param>
        /// <param name="privateKey">私钥</param>
        /// <returns></returns>
        public static string Sign(string content, string privateKey)
        {      
            byte[] Data = Encoding.GetEncoding("utf-8").GetBytes(content);
            RSACryptoServiceProvider rsa = DecodePemPrivateKey(privateKey);
            SHA1 sh = new SHA1CryptoServiceProvider();
           
            byte[] signData = rsa.SignData(Data, sh);
            sh.Clear();
            return Convert.ToBase64String(signData);
        }
 
        /// <summary>
        /// 对prikey进行处理，C#API默认的prikey是xml格式的，所以需要进行处理
        /// </summary>
        /// <param name="pemstr"></param>
        /// <returns></returns>
        private static RSACryptoServiceProvider DecodePemPrivateKey(String pemstr)
        {
            byte[] pkcs8privatekey;
            pkcs8privatekey = Convert.FromBase64String(pemstr);
            if (pkcs8privatekey != null)
            {
 
                RSACryptoServiceProvider rsa = DecodePrivateKeyInfo(pkcs8privatekey);
                return rsa;
            }
            else
                return null;
        }
 
        /// <summary>
        /// 转换prikey
        /// </summary>
        /// <param name="pkcs8"></param>
        /// <returns></returns>
        private static RSACryptoServiceProvider DecodePrivateKeyInfo(byte[] pkcs8)
        {
 
            byte[] SeqOID = { 0x30, 0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01, 0x05, 0x00 };
            byte[] seq = new byte[15];
 
            MemoryStream mem = new MemoryStream(pkcs8);
            int lenstream = (int)mem.Length;
            BinaryReader binr = new BinaryReader(mem);  
            byte bt = 0;
            ushort twobytes = 0;
 
            try
            {
 
                twobytes = binr.ReadUInt16();
                if (twobytes == 0x8130) 
                    binr.ReadByte();   
                else if (twobytes == 0x8230)
                    binr.ReadInt16();  
                else
                    return null;
 
 
                bt = binr.ReadByte();
                if (bt != 0x02)
                    return null;
 
                twobytes = binr.ReadUInt16();
 
                if (twobytes != 0x0001)
                    return null;
 
                seq = binr.ReadBytes(15);      
                if (!CompareBytearrays(seq, SeqOID))   
                    return null;
 
                bt = binr.ReadByte();
                if (bt != 0x04) 
                    return null;
 
                bt = binr.ReadByte();      
                if (bt == 0x81)
                    binr.ReadByte();
                else
                    if (bt == 0x82)
                        binr.ReadUInt16();
                
                byte[] rsaprivkey = binr.ReadBytes((int)(lenstream - mem.Position));
                RSACryptoServiceProvider rsacsp = DecodeRSAPrivateKey(rsaprivkey);
                return rsacsp;
            }
 
            catch (Exception)
            {
                return null;
            }
 
            finally { binr.Close(); }
 
        }
 
 
        private static bool CompareBytearrays(byte[] a, byte[] b)
        {
            if (a.Length != b.Length)
                return false;
            int i = 0;
            foreach (byte c in a)
            {
                if (c != b[i])
                    return false;
                i++;
            }
            return true;
        }
 
        /// <summary>
        /// 处理私钥
        /// </summary>
        /// <param name="privkey"></param>
        /// <returns></returns>
        private static RSACryptoServiceProvider DecodeRSAPrivateKey(byte[] privkey)
        {
            byte[] MODULUS, E, D, P, Q, DP, DQ, IQ;
 
           
            MemoryStream mem = new MemoryStream(privkey);
            BinaryReader binr = new BinaryReader(mem);   
            byte bt = 0;
            ushort twobytes = 0;
            int elems = 0;
            try
            {
                twobytes = binr.ReadUInt16();
                if (twobytes == 0x8130) 
                    binr.ReadByte();    
                else if (twobytes == 0x8230)
                    binr.ReadInt16();   
                else
                    return null;
 
                twobytes = binr.ReadUInt16();
                if (twobytes != 0x0102) 
                    return null;
                bt = binr.ReadByte();
                if (bt != 0x00)
                    return null;
 
 
                elems = GetIntegerSize(binr);
                MODULUS = binr.ReadBytes(elems);
 
                elems = GetIntegerSize(binr);
                E = binr.ReadBytes(elems);
 
                elems = GetIntegerSize(binr);
                D = binr.ReadBytes(elems);
 
                elems = GetIntegerSize(binr);
                P = binr.ReadBytes(elems);
 
                elems = GetIntegerSize(binr);
                Q = binr.ReadBytes(elems);
 
                elems = GetIntegerSize(binr);
                DP = binr.ReadBytes(elems);
 
                elems = GetIntegerSize(binr);
                DQ = binr.ReadBytes(elems);
 
                elems = GetIntegerSize(binr);
                IQ = binr.ReadBytes(elems);
 
                CspParameters cspParams = new CspParameters();
                cspParams.Flags = CspProviderFlags.UseMachineKeyStore;
                         //System.Security.Cryptography.RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(1024, cspParams); 
                                 RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(1024);
                RSAParameters RSAparams = new RSAParameters();
                RSAparams.Modulus = MODULUS;
                RSAparams.Exponent = E;
                RSAparams.D = D;
                RSAparams.P = P;
                RSAparams.Q = Q;
                RSAparams.DP = DP;
                RSAparams.DQ = DQ;
                RSAparams.InverseQ = IQ;
                RSA.ImportParameters(RSAparams);
                return RSA;
            }
            catch (Exception)
            {
                return null;
            }
            finally { binr.Close(); }
        }
 
        /// <summary>
        /// 获取binr的长度
        /// </summary>
        /// <param name="binr"></param>
        /// <returns></returns>
        private static int GetIntegerSize(BinaryReader binr)
        {
            byte bt = 0;
            byte lowbyte = 0x00;
            byte highbyte = 0x00;
            int count = 0;
            bt = binr.ReadByte();
            if (bt != 0x02)     
                return 0;
            bt = binr.ReadByte();
 
            if (bt == 0x81)
                count = binr.ReadByte();    
            else
                if (bt == 0x82)
                {
                    highbyte = binr.ReadByte(); 
                    lowbyte = binr.ReadByte();
                    byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };
                    count = BitConverter.ToInt32(modint, 0);
                }
                else
                {
                    count = bt;     
                }
 
            while (binr.ReadByte() == 0x00)
            {   
                count -= 1;
            }
            binr.BaseStream.Seek(-1, SeekOrigin.Current);       
            return count;
        }
    }
}

在主程序中添加如下代码：

using System;
using Android.App;
using Android.Widget;
using Android.OS;
using Java.Net;
 
namespace App1
{
    [Activity(Label = "App1", MainLauncher = true)]
    public class MainActivity : Activity
    { 
        // 合作商户ID。用签约支付宝账号登录ms.alipay.com后，在账户信息页面获取。
        public static string PARTNER = "替换你支付宝申请的partner";
        // 商户收款的支付宝账号
        public static string SELLER = "替换你支付宝申请的seller";
        //商户私密
        string RSA_PRIVATE = "替换你支付宝申请的private_key";
;
 
        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);
 
            SetContentView(Resource.Layout.Main);
            Button button = FindViewById<Button>(Resource.Id.MyButton);
 
            button.Click += HandleClick;
        }
 
        void HandleClick(object sender, EventArgs e)
        {
            System.Threading.Thread the = new System.Threading.Thread(Pay);
            the.Start();
        }
        void Pay()
        { 
            var con = getOrderInfo("test", "testbody");
            var sign = SignatureUtils.Sign(con, RSA_PRIVATE);
 
            sign = URLEncoder.Encode(sign, "utf-8");
 
            con += "&sign=\"" + sign + "\"&" + MySignType;
            Com.Alipay.Sdk.App.PayTask pa = new Com.Alipay.Sdk.App.PayTask(this);
            var result = pa.Pay(con);
            //调用结果查看result中是否返回是90000,如果是，则成功      
 
        }
         #region 组合
  
        public String getOrderInfo(String subject, String body)
        { 
            // 签约合作者身份ID
            String orderInfo = "partner=" + "\"" + PARTNER + "\""; 
            // 签约卖家支付宝账号
            orderInfo += "&seller_id=" + "\"" + SELLER + "\""; 
            // 商户网站唯一订单号
            orderInfo += "&out_trade_no=" + "\"DJ" + DateTime.Now.ToString("yyyyMMddhhmmss") + "\""; 
            // 商品名称
            orderInfo += "&subject=" + "\"" + subject + "\""; 
            // 商品详情
            orderInfo += "&body=" + "\"" + body + "\""; 
            // 商品金额
            orderInfo += "&total_fee=" + "\"" + 0.01 + "\""; 
            // 服务器异步通知页面路径
            orderInfo += "&notify_url=" + "\"" + "http://notify.msp.hk/notify.htm"
                    + "\""; 
            // 服务接口名称， 固定值

orderInfo += "&service=\"mobile.securitypay.pay\"";

// 支付类型，固定值

orderInfo += "&payment_type=\"1\"";

// 参数编码，固定值

orderInfo += "&_input_charset=\"utf-8\"";

// 设置未付款交易的超时时间

// 默认30分钟，一旦超时，该笔交易就会自动被关闭。

// 取值范围：1m～15d。

// m-分钟，h-小时，d-天，1c-当天（无论交易何时创建，都在0点关闭）。

// 该参数数值不接受小数点，如1.5h，可转换为90m。

orderInfo += "&it_b_pay=\"30m\"";

// extern_token为经过快登授权获取到的alipay_open_id,带上此参数用户将使用授权的账户进行支付

// orderInfo += "&extern_token=" + "\"" + extern_token + "\"";

// 支付宝处理完请求后，当前页面跳转到商户指定页面的路径，可空

orderInfo += "&return_url=\"m.alipay.com\"";

// 调用银行卡支付，需配置此参数，参与签名，固定值（需要签约《无线银行卡快捷支付》才能使用）

// orderInfo += "&paymethod=\"expressGateway\"";

return orderInfo;

}

public String MySignType

{

get

{

return "sign_type=\"RSA\"";

}

#endregion

}

源代码见附件