Question

在我最新的Chrome更新到76版本之后，使用driver.Manage().Logs.GetLog(LogType.Browser)获取任何控制台日志的Selenium代码段引发错误。注意Logs.AvaialbleLogTypes抛出NullReference exception。我们需要启用任何设置吗？还有其他方法可以获取控制台错误

我尝试使用LoggingPreferences，但是返回无效的参数错误，并且无法打开Chrome驱动程序

Answer 1

这是我的快速而又肮脏的解决方案（直到硒4出炉，此问题已解决）-它正在起作用，您可以对其进行优化并添加更多的检查和验证。

我将其作为扩展方法GetBrowserLogs公开

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Chromium;
using OpenQA.Selenium.Remote;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Reflection;
using System.Text;

namespace SeleniumConsumer
{
    internal static class Program
    {
        private static void Main()
        {
            // setup options
            var options = new ChromeOptions();
            options.SetLoggingPreference(LogType.Browser, LogLevel.All);

            // do whatever actions
            var driver = new ChromeDriver(options)
            {
                Url = "https://www.yahoo.com/"
            };

            // extract logs
            foreach (var log in driver.GetBrowserLogs())
            {
                Console.WriteLine($"{log["timestamp"]}: {log["message"]}");
            }

            // cleanup
            driver.Dispose();
            Console.WriteLine();
            Console.WriteLine("Press any key to exit...");
            Console.ReadLine();
        }
    }

    public static class WebDriverExtensions
    {
        public static IEnumerable<IDictionary<string, object>> GetBrowserLogs(this IWebDriver driver)
        {
            // setup
            var endpoint = GetEndpoint(driver);
            var session = GetSession(driver);
            var resource = $"{endpoint}session/{session}/se/log";
            const string jsonBody = @"{""type"":""browser""}";

            // execute
            using (var httpClient = new HttpClient())
            {
                var content = new StringContent(jsonBody, Encoding.UTF8, "application/json");
                var response = httpClient.PostAsync(resource, content).GetAwaiter().GetResult();
                var responseBody = response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
                return AsLogEntries(responseBody);
            }
        }

        private static string GetEndpoint(IWebDriver driver)
        {
            // setup
            const BindingFlags Flags = BindingFlags.Instance | BindingFlags.NonPublic;

            // get RemoteWebDriver type
            var remoteWebDriver = GetRemoteWebDriver(driver.GetType());

            // get this instance executor > get this instance internalExecutor
            var executor = remoteWebDriver.GetField("executor", Flags).GetValue(driver) as DriverServiceCommandExecutor;
            var internalExecutor = executor.GetType().GetField("internalExecutor", Flags).GetValue(executor) as HttpCommandExecutor;

            // get URL
            var uri = internalExecutor.GetType().GetField("remoteServerUri", Flags).GetValue(internalExecutor) as Uri;

            // result
            return uri.AbsoluteUri;
        }

        private static Type GetRemoteWebDriver(Type type)
        {
            if (!typeof(RemoteWebDriver).IsAssignableFrom(type))
            {
                return type;
            }

            while(type != typeof(RemoteWebDriver))
            {
                type = type.BaseType;
            }

            return type;
        }

        private static SessionId GetSession(IWebDriver driver)
        {
            if (driver is IHasSessionId id)
            {
                return id.SessionId;
            }
            return new SessionId($"gravity-{Guid.NewGuid()}");
        }

        private static IEnumerable<IDictionary<string, object>> AsLogEntries(string responseBody)
        {
            // setup
            var value = $"{JToken.Parse(responseBody)["value"]}";
            return  JsonConvert.DeserializeObject<IEnumerable<Dictionary<string, object>>>(value);
        }
    }
}

Answer 2

此问题目前已被打破，仅在发布的Selenium 4 alpha中得到了修复：https://github.com/SeleniumHQ/selenium/issues/7342

从阅读问题开始，似乎需要对chromedriver进行更改，因此有必要对.Net Selenium实现进行更改以纠正此问题。

Selenium Webdriver 3.141.0 driver.Manage（）。Logs.AvailableLogTypes引发System.NullReference异常

2 个答案: