使用CefSharp捕获资源响应数据（正文） [英] Using CefSharp to capture Resource Response Data (body)

问题描述

我正在尝试使用CefSharp访问URL并捕获在加载给定页面期间检索到的特定资源。大概是每个资源的流或字节数组。

I am trying to use CefSharp to visit a URL and capture specific resources retrieved during the loading of a given page. Presumably as a Stream or byte array per resource.

CefSharp提供了接口IRequestHandler。您可以创建一个实现此接口的类以响应请求/响应事件，但不包含响应主体。

CefSharp provides the interface IRequestHandler. You can create a class which implements this interface to respond to Request/Response events, but it does not contain the response body in any way.

推荐答案

在实现 IRequestHandler 的过程中查看 GetResourceResponseFilter 。 GetResourceResponseFilter 返回 IResponseFilter ，这为您提供了捕获所有响应的机会。您需要实现自己的 IResponseFilter ，幸运的是，这里有很多示例。

Take a look at GetResourceResponseFilter in your implementation of IRequestHandler. GetResourceResponseFilter returns an IResponseFilter, which provides you with an opportunity to capture all responses. You'll need to implement your own IResponseFilter, thankfully there are ample examples.

示例 IResponseFilter 实现来自于 CefSharp GitHub项目。

Example IResponseFilter implementation taken from the CefSharp GitHub project.

public class MemoryStreamResponseFilter : IResponseFilter
{
        private MemoryStream memoryStream;

        bool IResponseFilter.InitFilter()
        {
            //NOTE: We could initialize this earlier, just one possible use of InitFilter
            memoryStream = new MemoryStream();

            return true;
        }

        FilterStatus IResponseFilter.Filter(Stream dataIn, out long dataInRead, Stream dataOut, out long dataOutWritten)
        {
            if (dataIn == null)
            {
                dataInRead = 0;
                dataOutWritten = 0;

                return FilterStatus.Done;
            }

            dataInRead = dataIn.Length;
            dataOutWritten = Math.Min(dataInRead, dataOut.Length);

            //Important we copy dataIn to dataOut
            dataIn.CopyTo(dataOut);

            //Copy data to stream
            dataIn.Position = 0;
            dataIn.CopyTo(memoryStream);

            return FilterStatus.Done;
        }

        void IDisposable.Dispose()
        {
            memoryStream.Dispose();
            memoryStream = null;
        }

        public byte[] Data
        {
            get { return memoryStream.ToArray(); }
        }
    }

现在在 GetResourceResponseFilter中方法：

 private Dictionary<ulong, MemoryStreamResponseFilter> responseDictionary = new Dictionary<ulong, MemoryStreamResponseFilter>();
 public IResponseFilter GetResourceResponseFilter(IWebBrowser browserControl, IBrowser browser, IFrame frame, IRequest request, IResponse response)
 {
       var dataFilter = new MemoryStreamResponseFilter();
       responseDictionary.Add(request.Identifier, dataFilter);
       return dataFilter;
 }

然后在 OnResourceLoadComplete

public void OnResourceLoadComplete(IWebBrowser browserControl, IBrowser browser, IFrame frame, IRequest request, IResponse response, UrlRequestStatus status, long receivedContentLength)
{      
    MemoryStreamResponseFilter filter;
    if (responseDictionary.TryGetValue(request.Identifier, out filter))
    {
        var data = filter.Data; //This returns a byte[]
        //File.WriteAllBytes("c:/save/path", data);
    }
}

您可以使用 IRequest 和 IResponse 参数来判断您要过滤的内容。

You can use the properties within the IRequest and IResponse parameters to judge what you want to filter.

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