何使用Amazon的AWS的中国地区的API，即CN版本的AWS的API

【问题】

别人问的：

我看了您的如下文章，范例中的Browse Node IDs返回的都是amazon.com的资料。我要返回amazon.cn的资料，我用了帮助文档中CN的Browse Node IDs，但是报：“80207071(一个ID)is not a valid value for BrowseNodeId. Please change this value and retry your request.”。 请问，还要改哪里呢？ http://www.crifan.com/continue_optimize_csharp_aws_api_itemlookup/

即，尝试去访问amazon的中国的部分，即CN，即amazon的术语中的endpoint是cn。

【解决过程】

1.参考：

http://docs.aws.amazon.com/AWSECommerceService/latest/DG/CHAP_WhatsNew.html

得知，当前用的，虽然不是最新的2011-08-02：

【记录】寻找AWSECommerceService的最新版本

但是，是比较新的，2011-08-01，其已经如上所述：

New Marketplace The IT (Italy) and CN (China) marketplaces were added. 1 August 2011

即，已经支持CN了。

2.用了默认的US的.com：

private static void cn_browseNodeLookupTest()
{
string _awsApiVersion = "2011-08-01";
string _awsDestination_cn = "ecs.amazonaws.com";

SignedRequestHelper helper_cn = new SignedRequestHelper(
awsAccessKeyId,
awsSecretKey,
awsAssociateTag,
_awsDestination_cn);

/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = _awsApiVersion;
reqDict["Operation"] = "BrowseNodeLookup";

//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//for CN: Appliances -> 80207071
reqDict["BrowseNodeId"] = "80207071";

reqDict["ResponseGroup"] = "BrowseNodeInfo";

/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;

requestUrl = helper_cn.Sign(reqDict);

//WebRequest request = HttpWebRequest.Create(requestUrl);
//WebResponse response = request.GetResponse();
//XmlDocument doc = new XmlDocument();
//doc.Load(response.GetResponseStream());

XmlDocument xmlDoc = new XmlDocument();
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(requestUrl);
req.Method = "GET";
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr;
string charset = "UTF-8";
Encoding htmlEncoding = Encoding.GetEncoding(charset);
sr = new StreamReader(resp.GetResponseStream(), htmlEncoding);
string respHtml = sr.ReadToEnd();
sr.Close();
resp.Close();
xmlDoc.LoadXml(respHtml);

System.Console.WriteLine(xmlDoc.InnerXml);
}

返回xml是：

<BrowseNodeLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2011-08-01">
<OperationRequest>
<RequestId>c7fada9f-13da-4312-bcfb-10c16eb3d035</RequestId>
<Arguments>
<Argument Name="Operation" Value="BrowseNodeLookup"/>
<Argument Name="Service" Value="AWSECommerceService"/>
<Argument Name="Signature" Value="bD9/dUvxjPx63vIUHs+WeksSj9MPJUQ0fsLMlFiLbfE="/>
<Argument Name="AssociateTag" Value="xxx"/>
<Argument Name="Version" Value="2011-08-01"/>
<Argument Name="BrowseNodeId" Value="80207071"/>
<Argument Name="AWSAccessKeyId" Value="xxx"/>
<Argument Name="Timestamp" Value="2013-06-22T07:39:39Z"/>
<Argument Name="ResponseGroup" Value="BrowseNodeInfo"/>
</Arguments>
<RequestProcessingTime>0.011964</RequestProcessingTime>
</OperationRequest>
<BrowseNodes>
<Request>
<IsValid>True</IsValid>
<BrowseNodeLookupRequest>
<BrowseNodeId>80207071</BrowseNodeId>
<ResponseGroup>BrowseNodeInfo</ResponseGroup>
</BrowseNodeLookupRequest>
<Errors>
<Error>
<Code>AWS.InvalidParameterValue</Code>
<Message>80207071 is not a valid value for BrowseNodeId. Please change this value and retry your request.</Message>
</Error>
</Errors>
</Request>
</BrowseNodes>
</BrowseNodeLookupResponse>

即，和预期的一样，是无效的id。

3.又去试了试，用.cn的：

private static void cn_browseNodeLookupTest()
{
string _awsApiVersion = "2011-08-01";
string _awsDestination_cn = "ecs.amazonaws.cn";

SignedRequestHelper helper_cn = new SignedRequestHelper(
awsAccessKeyId,
awsSecretKey,
awsAssociateTag,
_awsDestination_cn);

/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = _awsApiVersion;
reqDict["Operation"] = "BrowseNodeLookup";

//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//for CN: Appliances -> 80207071
reqDict["BrowseNodeId"] = "80207071";

reqDict["ResponseGroup"] = "BrowseNodeInfo";

/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;

requestUrl = helper_cn.Sign(reqDict);

//WebRequest request = HttpWebRequest.Create(requestUrl);
//WebResponse response = request.GetResponse();
//XmlDocument doc = new XmlDocument();
//doc.Load(response.GetResponseStream());

XmlDocument xmlDoc = new XmlDocument();
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(requestUrl);
req.Method = "GET";
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr;
string charset = "UTF-8";
Encoding htmlEncoding = Encoding.GetEncoding(charset);
sr = new StreamReader(resp.GetResponseStream(), htmlEncoding);
string respHtml = sr.ReadToEnd();
sr.Close();
resp.Close();
xmlDoc.LoadXml(respHtml);

System.Console.WriteLine(xmlDoc.InnerXml);
}

结果更离谱，返回是看不懂的html内容：

<html><head></head><script type="text/javascript"> var sa = " <a href="http://202.102.110.207:8080/" ;"="" style="color: rgb(148, 148, 148); text-decoration: none; transition: 0.25s; -webkit-transition: 0.25s; border-bottom-width: 1px; border-bottom-style: dashed; border-bottom-color: rgb(148, 148, 148); font-style: italic; font-weight: bold;">http://202.102.110.207:8080/"; var pp = "107&pre="+(new Date()).getTime(); var s=String(window.location.href); var host=escape(s.substring(7,s.indexOf(‘/’,7))); var ref=escape(document.referrer); var su = s+"&host="+host+"&refer="+ref+"&server="+pp; s = escape(s); function loadfr(){ document.getElementById("fr1").src = sa+"3.htm?AIMT="+su; } function refreshPage(){ document.location = sa+"2.htm?AIMT="+su; } if (self.location == top.location){ document.location= sa+"1.htm?AIMT="+su; } else { refreshPage(); }</script><frameset rows="*,0"><frame id="main" src=""> <frame id="fr1" src=""></frameset><body></body></html>

而不是xml，所以也会导致后面的：

xmlDoc.LoadXml(respHtml);

报错的。

4.再去参考：

http://docs.aws.amazon.com/AWSECommerceService/latest/DG/AnatomyOfaRESTRequest.html#EndpointsandWebServices

去试试那个

CN http://webservices.amazon.cn/onca/xml https://webservices.amazon.cn/onca/xml

代码是：

private static void cn_browseNodeLookupTest()
{
string _awsApiVersion = "2011-08-01";
//string _awsDestination_cn = "ecs.amazonaws.com";
//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/AnatomyOfaRESTRequest.html#EndpointsandWebServices
string _awsDestination_cn = "webservices.amazon.cn";

SignedRequestHelper helper_cn = new SignedRequestHelper(
awsAccessKeyId,
awsSecretKey,
awsAssociateTag,
_awsDestination_cn);

/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = _awsApiVersion;
reqDict["Operation"] = "BrowseNodeLookup";

//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//for CN: Appliances -> 80207071
reqDict["BrowseNodeId"] = "80207071";

reqDict["ResponseGroup"] = "BrowseNodeInfo";

/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;

requestUrl = helper_cn.Sign(reqDict);

//WebRequest request = HttpWebRequest.Create(requestUrl);
//WebResponse response = request.GetResponse();
//XmlDocument doc = new XmlDocument();
//doc.Load(response.GetResponseStream());

XmlDocument xmlDoc = new XmlDocument();
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(requestUrl);
req.Method = "GET";
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr;
string charset = "UTF-8";
Encoding htmlEncoding = Encoding.GetEncoding(charset);
sr = new StreamReader(resp.GetResponseStream(), htmlEncoding);
string respHtml = sr.ReadToEnd();
sr.Close();
resp.Close();
xmlDoc.LoadXml(respHtml);

System.Console.WriteLine(xmlDoc.InnerXml);
}

结果是就可以了：

<BrowseNodeLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2011-08-01">
<OperationRequest>
<RequestId>88394147-043d-4a5f-bb9d-6958b61b9da8</RequestId>
<Arguments>
<Argument Name="Operation" Value="BrowseNodeLookup"/>
<Argument Name="Service" Value="AWSECommerceService"/>
<Argument Name="Signature" Value="ovanQqg0HvvAD0d6qdANILaOwQANGBvjmhCKgtpl/kQ="/>
<Argument Name="AssociateTag" Value="xxx"/>
<Argument Name="Version" Value="2011-08-01"/>
<Argument Name="BrowseNodeId" Value="80207071"/>
<Argument Name="AWSAccessKeyId" Value="xxx"/>
<Argument Name="Timestamp" Value="2013-06-22T07:42:31Z"/>
<Argument Name="ResponseGroup" Value="BrowseNodeInfo"/>
</Arguments>
<RequestProcessingTime>0.001642</RequestProcessingTime>
</OperationRequest>
<BrowseNodes>
<Request>
<IsValid>True</IsValid>
<BrowseNodeLookupRequest>
<BrowseNodeId>80207071</BrowseNodeId>
<ResponseGroup>BrowseNodeInfo</ResponseGroup>
</BrowseNodeLookupRequest>
</Request>
<BrowseNode>
<BrowseNodeId>80207071</BrowseNodeId>
<Name>大家电</Name>
<Children>
<BrowseNode>
<BrowseNodeId>80208071</BrowseNodeId>
<Name>类别</Name>
<IsCategoryRoot>1</IsCategoryRoot>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>80209071</BrowseNodeId>
<Name>特色</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>81230071</BrowseNodeId>
<Name>推荐分类</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>81231071</BrowseNodeId>
<Name>Self Service</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>81232071</BrowseNodeId>
<Name>筛选</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>83190071</BrowseNodeId>
<Name>Archive</Name>
</BrowseNode>
</Children>
</BrowseNode>
</BrowseNodes>
</BrowseNodeLookupResponse>

不光是可以正常返回对应的BrowseNodeId，而且也是对应的中文的。

5.另外，顺带也去测了测2011-08-02版本的API：

private static void cn_browseNodeLookupTest()
{
//string _awsApiVersion = "2011-08-01";
//【记录】寻找AWSECommerceService的最新版本
//http://www.crifan.com/find_awsecommerceservice_latest_version
//http://aws.amazon.com/releasenotes/Product-Advertising-API/7764190151051019
string _awsApiVersion = "2011-08-02";

//string _awsDestination_cn = "ecs.amazonaws.com";
//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/AnatomyOfaRESTRequest.html#EndpointsandWebServices
string _awsDestination_cn = "webservices.amazon.cn";

SignedRequestHelper helper_cn = new SignedRequestHelper(
awsAccessKeyId,
awsSecretKey,
awsAssociateTag,
_awsDestination_cn);

/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = _awsApiVersion;
reqDict["Operation"] = "BrowseNodeLookup";

//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//for CN: Appliances -> 80207071
reqDict["BrowseNodeId"] = "80207071";

reqDict["ResponseGroup"] = "BrowseNodeInfo";

/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;

requestUrl = helper_cn.Sign(reqDict);

//WebRequest request = HttpWebRequest.Create(requestUrl);
//WebResponse response = request.GetResponse();
//XmlDocument doc = new XmlDocument();
//doc.Load(response.GetResponseStream());

XmlDocument xmlDoc = new XmlDocument();
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(requestUrl);
req.Method = "GET";
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr;
string charset = "UTF-8";
Encoding htmlEncoding = Encoding.GetEncoding(charset);
sr = new StreamReader(resp.GetResponseStream(), htmlEncoding);
string respHtml = sr.ReadToEnd();
sr.Close();
resp.Close();
xmlDoc.LoadXml(respHtml);

System.Console.WriteLine(xmlDoc.InnerXml);
}

结果是

<BrowseNodeLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2011-08-01">
<OperationRequest>
<RequestId>333bac99-0f9b-40b1-8182-1335ccd84c18</RequestId>
<Arguments>
<Argument Name="Operation" Value="BrowseNodeLookup"/>
<Argument Name="Service" Value="AWSECommerceService"/>
<Argument Name="Signature" Value="GrlWTbhkfwnAYQm4ui7+9BZLDoBclX89ZDZZmU3YZ6Q="/>
<Argument Name="AssociateTag" Value="xxx"/>
<Argument Name="Version" Value="2011-08-02"/>
<Argument Name="BrowseNodeId" Value="80207071"/>
<Argument Name="AWSAccessKeyId" Value="xxx"/>
<Argument Name="Timestamp" Value="2013-06-22T07:45:44Z"/>
<Argument Name="ResponseGroup" Value="BrowseNodeInfo"/>
</Arguments>
<RequestProcessingTime>0.002016</RequestProcessingTime>
</OperationRequest>
<BrowseNodes>
<Request>
<IsValid>True</IsValid>
<BrowseNodeLookupRequest>
<BrowseNodeId>80207071</BrowseNodeId>
<ResponseGroup>BrowseNodeInfo</ResponseGroup>
</BrowseNodeLookupRequest>
</Request>
<BrowseNode>
<BrowseNodeId>80207071</BrowseNodeId>
<Name>大家电</Name>
<Children>
<BrowseNode>
<BrowseNodeId>80208071</BrowseNodeId>
<Name>类别</Name>
<IsCategoryRoot>1</IsCategoryRoot>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>80209071</BrowseNodeId>
<Name>特色</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>81230071</BrowseNodeId>
<Name>推荐分类</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>81231071</BrowseNodeId>
<Name>Self Service</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>81232071</BrowseNodeId>
<Name>筛选</Name>
</BrowseNode>
<BrowseNode>
<BrowseNodeId>83190071</BrowseNodeId>
<Name>Archive</Name>
</BrowseNode>
</Children>
</BrowseNode>
</BrowseNodes>
</BrowseNodeLookupResponse>

即，和以前用2011-08-02访问.com的效果一样：

虽然你用的是2011-08-02，但是返回结果却是2011-08-01，直接被服务器无视了。。。

【总结】

如果想要正常访问对应的CN版本的AWS的API的话，则要：

1.使用正确的endpoint，此处对于CN的是：

http://webservices.amazon.cn/onca/xml

或：

https://webservices.amazon.cn/onca/xml

注意：

（1）之前参考官网的代码，用的是（估计是旧的）基于

ecs.amazonaws.com

而改成CN版本的：

ecs.amazonaws.cn

结果是无效的。

最新的值，都还是参考官网最新的，关于各种endpoint的解释

Anatomy of a REST Request

中的：

CN http://webservices.amazon.cn/onca/xml https://webservices.amazon.cn/onca/xml

2.然后再用最新的API，此处即2011-08-01。

注意：

（1）即使你用，我之前去调查到的：

【记录】寻找AWSECommerceService的最新版本

最新的2011-08-02，结果服务器也不认，还是返回给你2011-08-01的结果。

3. 此处附上完整的代码：

（1）SignedRequestHelper.cs

/*
* [Function]
* Implement Amazon AWS API, focus on ItemLookup, ItemSearch, BrowseNodeLookup
* code based on:
* Product Advertising API Signed Requests Sample Code - C# REST/QUERY
* http://aws.amazon.com/code/Product-Advertising-API/2480 * ->
* http://associates-amazon.s3.amazonaws.com/signed-requests/samples/amazon-product-advt-api-sample-csharp-query.zip *
* [Author]
* Crifan Li
*
* [Date]
* 2013-06-13
*
* [Contact]
* http://www.crifan.com/contact_me/ */

using System;
using System.Collections.Generic;
using System.Text;
using System.Web;
using System.Security.Cryptography;

namespace AmazonProductAdvtApi
{
class SignedRequestHelper
{
private string endPoint;
private string akid;

//added by Crifan Li
//https://affiliate-program.amazon.co.uk/gp/advertising/api/detail/api-changes.html?ie=UTF8&pf_rd_t=501&ref_=amb_link_83388313_2&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_p=&pf_rd_s=assoc-center-1&pf_rd_r=&pf_rd_i=assoc-api-detail-2-v2
//Product Advertising API Change Details
//Associate Tag Parameter: Every request made to the API should include a valid Associate Tag. Any request that does not contain a valid Associate Tag will be rejected with an appropriate error message. For details on the Associate Tag parameter, please refer to our Developer guide.
//-> must add this Associate Tag, otherwise will return:
//<Error>
//    <Code>AWS.MissingParameters</Code>
//    <Message>Your request is missing required parameters. Required parameters include AssociateTag.</Message>
//</Error>
private string associateTag;

private byte[] secret;
private HMAC signer;

private const string REQUEST_URI = "/onca/xml";
private const string REQUEST_METHOD = "GET";

/*
* Use this constructor to create the object. The AWS credentials are available on
* http://aws.amazon.com *
* The destination is the service end-point for your application:
*  US: ecs.amazonaws.com
*  JP: ecs.amazonaws.jp
*  UK: ecs.amazonaws.co.uk
*  DE: ecs.amazonaws.de
*  FR: ecs.amazonaws.fr
*  CA: ecs.amazonaws.ca
*/
public SignedRequestHelper(string awsAccessKeyId, string awsSecretKey, string awsAssociateTag, string destination)
{
this.endPoint = destination.ToLower();
this.akid = awsAccessKeyId;

//added by Crifan Li
this.associateTag = awsAssociateTag;

this.secret = Encoding.UTF8.GetBytes(awsSecretKey);
this.signer = new HMACSHA256(this.secret);
}

/*
* Sign a request in the form of a Dictionary of name-value pairs.
*
* This method returns a complete URL to use. Modifying the returned URL
* in any way invalidates the signature and Amazon will reject the requests.
*/
public string Sign(IDictionary<string, string> request)
{
// Use a SortedDictionary to get the parameters in naturual byte order, as
// required by AWS.
ParamComparer pc = new ParamComparer();
SortedDictionary<string, string> sortedMap = new SortedDictionary<string, string>(request, pc);

// Add the AWSAccessKeyId and Timestamp to the requests.
sortedMap["AWSAccessKeyId"] = this.akid;

//added by Crifan Li
sortedMap["AssociateTag"] = this.associateTag;

sortedMap["Timestamp"] = this.GetTimestamp();

// Get the canonical query string
string canonicalQS = this.ConstructCanonicalQueryString(sortedMap);

// Derive the bytes needs to be signed.
StringBuilder builder = new StringBuilder();
builder.Append(REQUEST_METHOD)
.Append("\n")
.Append(this.endPoint)
.Append("\n")
.Append(REQUEST_URI)
.Append("\n")
.Append(canonicalQS);

string stringToSign = builder.ToString();
byte[] toSign = Encoding.UTF8.GetBytes(stringToSign);

// Compute the signature and convert to Base64.
byte[] sigBytes = signer.ComputeHash(toSign);
string signature = Convert.ToBase64String(sigBytes);

// now construct the complete URL and return to caller.
StringBuilder qsBuilder = new StringBuilder();
qsBuilder.Append("http://")
.Append(this.endPoint)
.Append(REQUEST_URI)
.Append("?")
.Append(canonicalQS)
.Append("&Signature=")
.Append(this.PercentEncodeRfc3986(signature));

return qsBuilder.ToString();
}

/*
* Sign a request in the form of a query string.
*
* This method returns a complete URL to use. Modifying the returned URL
* in any way invalidates the signature and Amazon will reject the requests.
*/
public string Sign(string queryString)
{
IDictionary<string, string> request = this.CreateDictionary(queryString);
return this.Sign(request);
}

/*
* Current time in IS0 8601 format as required by Amazon
*/
private string GetTimestamp()
{
DateTime currentTime = DateTime.UtcNow;
string timestamp = currentTime.ToString("yyyy-MM-ddTHH:mm:ssZ");
return timestamp;
}

/*
* Percent-encode (URL Encode) according to RFC 3986 as required by Amazon.
*
* This is necessary because .NET's HttpUtility.UrlEncode does not encode
* according to the above standard. Also, .NET returns lower-case encoding
* by default and Amazon requires upper-case encoding.
*/
private string PercentEncodeRfc3986(string str)
{
str = HttpUtility.UrlEncode(str, System.Text.Encoding.UTF8);
str = str.Replace("'", "%27").Replace("(", "%28").Replace(")", "%29").Replace("*", "%2A").Replace("!", "%21").Replace("%7e", "~").Replace("+", "%20");

StringBuilder sbuilder = new StringBuilder(str);
for (int i = 0; i < sbuilder.Length; i++)
{
if (sbuilder[i] == '%')
{
if (Char.IsLetter(sbuilder[i + 1]) || Char.IsLetter(sbuilder[i + 2]))
{
sbuilder[i + 1] = Char.ToUpper(sbuilder[i + 1]);
sbuilder[i + 2] = Char.ToUpper(sbuilder[i + 2]);
}
}
}
return sbuilder.ToString();
}

/*
* Convert a query string to corresponding dictionary of name-value pairs.
*/
private IDictionary<string, string> CreateDictionary(string queryString)
{
Dictionary<string, string> map = new Dictionary<string, string>();

string[] requestParams = queryString.Split('&');

for (int i = 0; i < requestParams.Length; i++)
{
if (requestParams[i].Length < 1)
{
continue;
}

char[] sep = { '=' };
string[] param = requestParams[i].Split(sep, 2);
for (int j = 0; j < param.Length; j++)
{
param[j] = HttpUtility.UrlDecode(param[j], System.Text.Encoding.UTF8);
}
switch (param.Length)
{
case 1:
{
if (requestParams[i].Length >= 1)
{
if (requestParams[i].ToCharArray()[0] == '=')
{
map[""] = param[0];
}
else
{
map[param[0]] = "";
}
}
break;
}
case 2:
{
if (!string.IsNullOrEmpty(param[0]))
{
map[param[0]] = param[1];
}
}
break;
}
}

return map;
}

/*
* Consttuct the canonical query string from the sorted parameter map.
*/
private string ConstructCanonicalQueryString(SortedDictionary<string, string> sortedParamMap)
{
StringBuilder builder = new StringBuilder();

if (sortedParamMap.Count == 0)
{
builder.Append("");
return builder.ToString();
}

foreach (KeyValuePair<string, string> kvp in sortedParamMap)
{
builder.Append(this.PercentEncodeRfc3986(kvp.Key));
builder.Append("=");
builder.Append(this.PercentEncodeRfc3986(kvp.Value));
builder.Append("&");
}
string canonicalString = builder.ToString();
canonicalString = canonicalString.Substring(0, canonicalString.Length - 1);
return canonicalString;
}
}

/*
* To help the SortedDictionary order the name-value pairs in the correct way.
*/
class ParamComparer : IComparer<string>
{
public int Compare(string p1, string p2)
{
return string.CompareOrdinal(p1, p2);
}
}
}

（2）ItemLookupSample.cs

/*
* [Function]
* Implement Amazon AWS API, focus on ItemLookup, ItemSearch, BrowseNodeLookup
* code based on:
* Product Advertising API Signed Requests Sample Code - C# REST/QUERY
* http://aws.amazon.com/code/Product-Advertising-API/2480 * ->
* http://associates-amazon.s3.amazonaws.com/signed-requests/samples/amazon-product-advt-api-sample-csharp-query.zip *
* [Author]
* Crifan Li
*
* [Date]
* 2013-06-20
*
* [Contact]
* http://www.crifan.com/contact_me/ */

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.IO;
using System.Xml;
using System.Xml.XPath;

namespace AmazonProductAdvtApi
{
class ItemLookupSample
{
//【记录】申请AWS的AWSAccessKeyId（AWS Access Key ID）
//http://www.crifan.com/apply_aws_access_key_id/
private const string awsAccessKeyId = "change to your access key id";
private const string awsSecretKey = "change to your secret key";
private const string awsAssociateTag = "change to your associate tag";

private const string awsDestination = "ecs.amazonaws.com";

//【记录】寻找AWSECommerceService的最新版本
//http://www.crifan.com/find_awsecommerceservice_latest_version
//http://aws.amazon.com/releasenotes/Product-Advertising-API/7764190151051019
//private const string awsApiVersion = "2011-08-02";
private const string awsApiVersion = "2011-08-01";

//private const string NAMESPACE = "http://webservices.amazon.com/AWSECommerceService/2009-03-31";
//private const string NAMESPACE = "http://webservices.amazon.com/AWSECommerceService/2011-08-01";
private const string NAMESPACE = "http://webservices.amazon.com/AWSECommerceService/" + awsApiVersion;
//private const string ITEM_ID   = "0545010225";

//private const string ITEM_ID = "B0083PWAPW";

//<Item>
//    <ASIN>B0083PWAPW</ASIN>
//    <ParentASIN>B008GGCAVM</ParentASIN>
//</Item>
private const string ITEM_ID = "B008GGCAVM";

private static void itemSearchTest(SignedRequestHelper helper)
{
/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = awsApiVersion;
reqDict["Operation"] = "ItemSearch";

//reqDict["SearchIndex"] = "None";
reqDict["SearchIndex"] = "HomeGarden";
reqDict["ResponseGroup"] = "ItemIds";

//Home & Kitchen ->  Heating, Cooling & Air Quality -> Air Conditioners & Accessories ->  Energy Star Qualified
//reqDict["BrowseNodeId"] = "3737761";
reqDict["BrowseNode"] = "3737761";

reqDict["ItemPage"] = "6";

String requestUrl = helper.Sign(reqDict);
WebRequest request = HttpWebRequest.Create(requestUrl);
WebResponse response = request.GetResponse();
XmlDocument doc = new XmlDocument();
doc.Load(response.GetResponseStream());
//for debug
System.Console.WriteLine(doc.InnerXml);
}

private static void browseNodeLookupTest(SignedRequestHelper helper)
{
/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = awsApiVersion;
reqDict["Operation"] = "BrowseNodeLookup";
//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//2619525011 -> Appliances
//reqDict["BrowseNodeId"] = "2619525011";

//<BrowseNodeId>2619525011</BrowseNodeId>
//<Name>Appliances</Name>
//<Children>
//    <BrowseNode>
//        <BrowseNodeId>2619526011</BrowseNodeId>
//        <Name>Categories</Name>
//        <IsCategoryRoot>1</IsCategoryRoot>
//    </BrowseNode>
//reqDict["BrowseNodeId"] = "2619526011";

//<Children>
//    <BrowseNode>
//        <BrowseNodeId>3737671</BrowseNodeId>
//        <Name>Air Conditioners</Name>
//    </BrowseNode>
//reqDict["BrowseNodeId"] = "3737671";

//<BrowseNode>
//    <BrowseNodeId>3737671</BrowseNodeId>
//    <Name>Air Conditioners & Accessories</Name>
//    <Children>
//        <BrowseNode>
//            <BrowseNodeId>3737761</BrowseNodeId>
//            <Name>Energy Star Qualified</Name>
//        </BrowseNode>
//reqDict["BrowseNodeId"] = "3737761";

//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//for CN: Appliances -> 80207071
reqDict["BrowseNodeId"] = "80207071";

reqDict["ResponseGroup"] = "BrowseNodeInfo";

/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;

requestUrl = helper.Sign(reqDict);
WebRequest request = HttpWebRequest.Create(requestUrl);
WebResponse response = request.GetResponse();
XmlDocument doc = new XmlDocument();
doc.Load(response.GetResponseStream());

//for debug
System.Console.WriteLine(doc.InnerXml);
}

private static void cn_browseNodeLookupTest()
{
string _awsApiVersion = "2011-08-01";
//【记录】寻找AWSECommerceService的最新版本
//http://www.crifan.com/find_awsecommerceservice_latest_version
//http://aws.amazon.com/releasenotes/Product-Advertising-API/7764190151051019
//string _awsApiVersion = "2011-08-02";

//string _awsDestination_cn = "ecs.amazonaws.com";
//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/AnatomyOfaRESTRequest.html#EndpointsandWebServices
string _awsDestination_cn = "webservices.amazon.cn";

SignedRequestHelper helper_cn = new SignedRequestHelper(
awsAccessKeyId,
awsSecretKey,
awsAssociateTag,
_awsDestination_cn);

/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = _awsApiVersion;
reqDict["Operation"] = "BrowseNodeLookup";

//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//for CN: Appliances -> 80207071
reqDict["BrowseNodeId"] = "80207071";

reqDict["ResponseGroup"] = "BrowseNodeInfo";

/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;

requestUrl = helper_cn.Sign(reqDict);

//WebRequest request = HttpWebRequest.Create(requestUrl);
//WebResponse response = request.GetResponse();
//XmlDocument doc = new XmlDocument();
//doc.Load(response.GetResponseStream());

XmlDocument xmlDoc = new XmlDocument();
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(requestUrl);
req.Method = "GET";
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr;
string charset = "UTF-8";
Encoding htmlEncoding = Encoding.GetEncoding(charset);
sr = new StreamReader(resp.GetResponseStream(), htmlEncoding);
string respHtml = sr.ReadToEnd();
sr.Close();
resp.Close();
xmlDoc.LoadXml(respHtml);

System.Console.WriteLine(xmlDoc.InnerXml);
}

public static void Main()
{
SignedRequestHelper helper = new SignedRequestHelper(awsAccessKeyId, awsSecretKey, awsAssociateTag, awsDestination);

//itemSearchTest(helper);
//browseNodeLookupTest(helper);

cn_browseNodeLookupTest();

/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
//r1["Version"] = "2009-03-31";
//r1["Version"] = "2009-03-31";
//reqDict["Version"] = "2011-08-02";
reqDict["Version"] = "2011-08-01";
reqDict["Operation"] = "ItemLookup";
reqDict["IdType"] = "ASIN";

//reqDict["ItemId"] = ITEM_ID;
string asin = "B004ZGN6MY";
//string asin = "B00008OE6I";
reqDict["ItemId"] = asin;

//reqDict["ResponseGroup"] = "Small";
//reqDict["ResponseGroup"] = "OfferSummary";
//reqDict["ResponseGroup"] = "ItemAttributes";
//reqDict["ResponseGroup"] = "VariationSummary";
//reqDict["ResponseGroup"] = "Variations";
reqDict["ResponseGroup"] = "Accessories";

/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;
String title;

requestUrl = helper.Sign(reqDict);
title = FetchTitle(requestUrl);

System.Console.WriteLine("Method 1: ItemLookup Dictionary form.");
System.Console.WriteLine("Title is \"" + title + "\"");
System.Console.WriteLine();
}

private static string FetchTitle(string url)
{
try
{
WebRequest request = HttpWebRequest.Create(url);
WebResponse response = request.GetResponse();
XmlDocument doc = new XmlDocument();
doc.Load(response.GetResponseStream());

//for debug
System.Console.WriteLine(doc.InnerXml);

XmlNodeList errorMessageNodes = doc.GetElementsByTagName("Message", NAMESPACE);
if (errorMessageNodes != null && errorMessageNodes.Count > 0)
{
String message = errorMessageNodes.Item(0).InnerText;
return "Error: " + message + " (but signature worked)";
}

XmlNode titleNode = doc.GetElementsByTagName("Title", NAMESPACE).Item(0);
string title = titleNode.InnerText;

response.Close();

return title;
}
catch (Exception e)
{
System.Console.WriteLine("Caught Exception: " + e.Message);
System.Console.WriteLine("Stack Trace: " + e.StackTrace);
}

return null;
}
}
}

然后换成自己的awsAccessKeyId，awsSecretKey，awsAssociateTag，直接拿去用即可。

原文http://www.crifan.com/how_to_use_amzon_aws_api_cn_version/