c# – 使用AWS SDK for .NET或REST API从Amazon S3检索带有图像

src:"StreamFile.ashx?file="ObjKey"

现在,要更改源代码,您可以更新旧的HTML文件,并使用指向(StreamFile.ashx)Generic Handler的源创建新的HTML文件,或使用URL重写将旧URL写入新URL.这可以在IIS或web.config中完成.如果您在IIS中执行此操作,它将自动在您的web.config中添加代码.

<system.webServer>
    <rewrite>
      <rules>
        <rule name="Content">
          <match url="DevelopmentContent/Course/([a-zA-Z0-9]+)" />
          <action type="Rewrite" url="StreamFile.ashx/?file=course{R:1}" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>

上面的代码将在Src字符串中查找“DevelopmentContent / Course /”,如果找到则会将URL重写为StreamFile.ashx /？file = course {R：1}. R：1将是URL粗体部分的其余部分(DevelopmentContent / Course / xyz / xsd / x / sd / ds.htm),它应该映射到amazon S3中的对象键.在StreamHandler.ashx中现在将接收来自具有指定URL的服务器.然后,您可以从查询字符串(context.Request.QueryString [“file”])获取对象键,然后创建一个函数来获取所需的对象.

public void ProcessRequest(HttpContext context)
        {           
            var response = Gets3Response(context.Request.QueryString["file"]);
            if (response != null)
            {
                using (response)
                {
                    var mimEtype = response.ContentType;
                    context.Response.ContentType = mimEtype;
                    using (var responseStream = response.ResponseStream)
                    {
                        var buffer = new byte[8000];
                        var bytesRead = -1;
                        while ((bytesRead = responseStream.Read(buffer,buffer.Length)) > 0)
                        {
                            context.Response.OutputStream.Write(buffer,bytesRead);
                        }
                    }
                    context.Response.Flush();
                    context.Response.End();
                }
            }
            else
            {

                context.Response.Write("Unable to retrieve content!");

            }
        }




        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
    private static GetObjectResponse Gets3Response(string fileName)
        {
            GetObjectResponse response;
            if (fileName.Trim().Length == 0)
            {
                return null;
            }
            try
            {
                var request = new GetObjectRequest();
                request.WithBucketName(BucketName).WithKey(fileName);
                response = AmazonS3ClientProvider.CreateS3Client().GetObject(request);
            }
            catch (AmazonS3Exception amazonS3Exception)
            {
                if (amazonS3Exception.ErrorCode != null &&      (amazonS3Exception.ErrorCode.Equals("InvalidAccessKeyId") || amazonS3Exception.ErrorCode.Equals("InvalidSecurity")))
                {
                }
                return null;
            }
            catch (Exception ex)
            {
                return null;
            }

            return response;
        }

所以现在所有的HTTP请求都将使用您的服务器作为代理.