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CefSharp.ChromiumWebBrowser浏覽器的一些功能使用

1.配置支援AnyCpu編譯模式

2.使用Http代理服務

3.Cookie隔離,每個IWebBrowser執行個體的資料不共享

4.使用IResponseFilter擷取響應資料

  CefSharp從51版本以後開始支援AnyCpu編譯模式,首先需要在目前項目的csproj檔案的PropertyGroup節點下第一行增加一個配置項

<CefSharpAnyCpuSupport>true</CefSharpAnyCpuSupport>

然後在程式的啟動入口配置動态加載目标平台x86/x64的程式集:

[STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            AppDomain.CurrentDomain.AssemblyResolve += Resolver;
            Application.Run(new Form1());
        }

        private static Assembly Resolver(object sender, ResolveEventArgs args)
        {
            if (args.Name.StartsWith("CefSharp"))
            {
                string assemblyName = args.Name.Split(new[] { ',' }, 2)[0] + ".dll";
                string archSpecificPath = Path.Combine(AppDomain.CurrentDomain.SetupInformation.ApplicationBase,
                                                       Environment.Is64BitProcess ? "x64" : "x86",
                                                       assemblyName);
                return File.Exists(archSpecificPath)
                           ? Assembly.LoadFile(archSpecificPath)
                           : null;
            }
            return null;
        }      

  這種方法是根據運作的目标平台動态去加載對應的程式集,如果我們能明确運作平台則可以不用加上面的代碼邏輯,在目前項目App.config檔案的根節點下加入以下配置即可:

<runtime>
  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
    <probing privatePath="x64"/><!--如果是32位系統,則換成x86-->
  </assemblyBinding>
</runtime>
      

網上一些文章介紹的通過添加指令行參數CefCommandLineArgs的方式,我試了一下不管用,通過 CefSharpSettings.Proxy =  new ProxyOptions("ipadress", "prot", "username",  "password");  這句是可以配置成功的,但這個是全局配置,不能滿足獨立我要控制每個browser執行個體各自使用自己的代理伺服器。通過在初始化ChromiumWebBrowser的地方加入以下代碼可實作動态設定代理。

var browser = new ChromiumWebBrowser("url", context); 
browser.RequestHandler = new DefaultRequestHandler();
Cef.UIThreadTaskFactory.StartNew(delegate
{
       var rc = browser.GetBrowser().GetHost().RequestContext;
       rc.GetAllPreferences(true);
       var dict = new Dictionary<string, object>();
       dict.Add("mode", "fixed_servers");
       dict.Add("server", "ipaddress:prot"); //此處替換成實際 ip位址:端口
       string error;
       bool success = rc.SetPreference("proxy", dict, out error);
       if (!success)
       {
               Console.WriteLine("something happen with the prerence set up" + error);
       }
});      

如果代理服務有使用者名密碼的話,則需要在DefaultRequestHandler類裡重寫GetAuthCredentials方法,如下:

protected override bool GetAuthCredentials(IWebBrowser chromiumWebBrowser, IBrowser browser, string originUrl, bool isProxy, string host, int port, string realm, string scheme, IAuthCallback callback)
 {
      if (isProxy)
      {
           callback.Continue("username", "passwrod");
           return true;
      }
      return false;
}      

這樣就可以實作每個ChromiumWebBrowser運作執行個體獨立連接配接自己的代理伺服器了。

  要保證多個browser執行個體之間cookie不共享,就不要在全局設定CefSettings中設定CachePath值,應該在執行個體的RequestContextSettings中設定,可以設定成每個browser擁有獨立的緩存目錄。在RequestContext内添加的cookie隻有目前browser才能通路,進而實作cookie隔離。

var setting = new RequestContextSettings()
                {
                    CachePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "CefSharp\\Cache_" + name),
                    PersistSessionCookies = true,
                    PersistUserPreferences = true
                };
                var context = new RequestContext(setting);
                var cookieManager = context.GetCookieManager(null);
          //這樣設定的cookie不是全局的,隻有目前browser才能通路
                cookieManager.SetCookie("domain", new Cookie
                {
                    Name = "cookiename",
                    Value = "cookievalue",
                    Path = "/"
                });
                var browser = new ChromiumWebBrowser("url", context);      

   要擷取ChromiumWebBrowser中每個請求的響應body内容并不是那麼友善,拿到Frame的html内容倒是很簡單,使用IFrame的GetSourceAsync()方法就行,但有時候我們需要單個請求的響應結果,這就需要自定義實作IResponseFilter接口來實作響應資料的攔截。

  //DefaultResourceHandler的構造可以放在IRequestHandler的實作類的GetResourceRequestHandler方法内      
  class DefaultResourceHandler : ResourceRequestHandler
    {
        protected override IResponseFilter GetResourceResponseFilter(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, IResponse response)
        {
            if (response.MimeType.Equals("application/json", StringComparison.OrdinalIgnoreCase))
            {
                return JsonResponseFilter.CreateFilter(request.Identifier.ToString());
            }
            return null;
        }

        protected override void OnResourceLoadComplete(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, IResponse response, UrlRequestStatus status, long receivedContentLength)
        {
            var filter = JsonResponseFilter.GetFileter(request.Identifier.ToString()) as JsonResponseFilter;
            if (filter != null)
            {
                var encode = !string.IsNullOrEmpty(response.Charset)
                    ? Encoding.GetEncoding(response.Charset)
                    : Encoding.UTF8;
                using (var read = new StreamReader(filter.GetStream(), encode))
                {
                    var text = read.ReadToEnd();
                    Debug.WriteLine(text);
                }
            }
        }
    }

    public class JsonResponseFilter : IResponseFilter
    {
        private MemoryStream Stream;

        public JsonResponseFilter()
        {
            Stream = new MemoryStream();
        }

        public FilterStatus Filter(System.IO.Stream dataIn, out long dataInRead, System.IO.Stream dataOut, out long dataOutWritten)
        {
            try
            {
                if (dataIn == null || dataIn.Length == 0)
                {
                    dataInRead = 0;
                    dataOutWritten = 0;

                    return FilterStatus.Done;
                }

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

                dataIn.CopyTo(dataOut);
                dataIn.Seek(0, SeekOrigin.Begin);
                byte[] bs = new byte[dataIn.Length];
                dataIn.Read(bs, 0, bs.Length);

                Stream.Write(bs, 0, bs.Length);

                dataInRead = dataIn.Length;
                dataOutWritten = dataIn.Length;

                return FilterStatus.NeedMoreData;
            }
            catch (Exception ex)
            {
                dataInRead = dataIn.Length;
                dataOutWritten = dataIn.Length;

                return FilterStatus.Done;
            }
        }

        public bool InitFilter()
        {
            return true;
        }

        public Stream GetStream()
        {
            Stream.Seek(0, SeekOrigin.Begin);
            return Stream;
        }

        public void Dispose()
        {
        }

        private static Dictionary<string, IResponseFilter> _dictionary = new Dictionary<string, IResponseFilter>();

        public static IResponseFilter CreateFilter(string id)
        {
            var filter = new JsonResponseFilter();
            _dictionary[id] = filter;
            return filter;
        }

        public static IResponseFilter GetFileter(string id)
        {
            if (_dictionary.ContainsKey(id))
            {
                var filter = _dictionary[id];
                _dictionary.Remove(id);
                return filter;
            }
            return null;
        }
    }      

  為了截獲響應資料繞了這麼一大圈有點費勁,不過人家這種設計也是為了友善外部擴充,可以針對不同響應類型的response來實作IResponseFilter過濾器。

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