Question

我正在尝试让CefSharp.Wpf在VSTO Office加载项中工作，该加载项默认情况下已启用卷影副本，但是我无法找到禁用它的方法。在运行时，程序集被复制到一个临时位置（AppData\local\assembly ......等）；这样做的问题是，并非所有需要的文件都复制到CefSharp的程序集位置。实际上，在首次运行时，或者在为AppDomain创建新的卷影副本位置时，都会引发异常，因为甚至找不到cefsharp.core.dll。但是，此后，将创建cef程序集位置，但仅使用cefsharp.core.dll，因此任何连续执行都将找到cefsharp.core.dll，但是由于应用程序正在使用该卷影副本位置，因此不会找到其依赖项作为组装基地。

我尝试了几种方法来尝试显式设置库的位置，但是收效甚微：

kernel32 SetDllDirectory

namespace OutlookTools
{
    public partial class AdvPrint : Window
    {
        [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool SetDllDirectory(string lpPathName);

        // This resolves to the original build folder
        private static string cefFolder = new Uri(Path.GetDirectoryName(Assembly.GetExecutingAssembly().CodeBase)).LocalPath;

        public AdvPrint()
        {
            SetDllDirectory(cefFolder);
            InitializeCefSharp(); // First run exception is thrown here, before function is even executed (No cefsharp.core.dll)
            InitializeComponent();
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static void InitializeCefSharp()
        {

            CefSharpSettings.SubprocessExitIfParentProcessClosed = true;

            var settings = new CefSettings();

            settings.BrowserSubprocessPath = Path.Combine(cefFolder, "CefSharp.BrowserSubprocess.exe");
            settings.LocalesDirPath = Path.Combine(cefFolder, "locales");
            settings.ResourcesDirPath = cefFolder;

            // Make sure you set performDependencyCheck false
            Cef.Initialize(settings, performDependencyCheck: true, browserProcessHandler: null); // Final exception is thrown here
        }
    }
}

在此处使用AssemblyResolve方法进行了尝试：https://gist.github.com/BlackBooth/19ce027c4f68c1eb4fc1144988ca6662，但是解析器从未被命中，因为该程序集已经解析为卷影副本。

namespace OutlookTools
{
    public partial class AdvPrint : Window
    {
        // This resolves to the original build folder
        private static string cefFolder = new Uri(Path.GetDirectoryName(Assembly.GetExecutingAssembly().CodeBase)).LocalPath;
        public AdvPrint(Outlook.MailItem mailItem)
        {
            AppDomain.CurrentDomain.AssemblyResolve += ResolveAssembly;
            InitializeCefSharp(); // First run exception is thrown here, before function is even executed (No cefsharp.core.dll)
            InitializeComponent();
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static void InitializeCefSharp()
        {

            CefSharpSettings.SubprocessExitIfParentProcessClosed = true;

            var settings = new CefSettings();

            settings.BrowserSubprocessPath = Path.Combine(cefFolder, "CefSharp.BrowserSubprocess.exe");
            settings.LocalesDirPath = Path.Combine(cefFolder, "locales");
            settings.ResourcesDirPath = cefFolder;

            // Make sure you set performDependencyCheck false
            Cef.Initialize(settings, performDependencyCheck: true, browserProcessHandler: null); // Final exception is thrown here
        }

        /// <summary>
        /// Will attempt to load missing assemblies from build folder
        /// </summary>
        private static Assembly ResolveAssembly(object sender, ResolveEventArgs args)
        {
            if (args.Name.StartsWith("CefSharp"))
            {
                string assemblyName = args.Name.Split(new[] { ',' }, 2)[0] + ".dll";
                string subfolderPath = Path.Combine(cefFolder, assemblyName);
                return File.Exists(subfolderPath) ? Assembly.LoadFile(subfolderPath) : null;
            }

            return null;
        }
    }
}

尝试使用CefLibraryHandle类https://github.com/cefsharp/CefSharp/blob/master/CefSharp/CefLibraryHandle.cs和此线程中描述的用法手动加载libcef.dll：https://github.com/cefsharp/CefSharp/issues/601

    public partial class AdvPrint : Window
    {
        // This resolves to the original build folder
        private static string cefFolder = new Uri(Path.GetDirectoryName(Assembly.GetExecutingAssembly().CodeBase)).LocalPath;

        public AdvPrint(Outlook.MailItem mailItem)
        {
            var libraryLoader = new CefLibraryHandle(Path.Combine(cefFolder, "libcef.dll"));
            //Calls to CEF cannot be made directly in this method, doing so would
            //attempt to load `CefSharp.Core` which requires `libcef.dll` which
            //we are now dynamically loading from our own folder. 
            InitializeCefSharp(); // First run exception is thrown here, before function is even executed (No cefsharp.core.dll)
            libraryLoader.Dispose();
            InitializeComponent();
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static void InitializeCefSharp()
        {

            CefSharpSettings.SubprocessExitIfParentProcessClosed = true;

            var settings = new CefSettings();

            settings.BrowserSubprocessPath = Path.Combine(cefFolder, "CefSharp.BrowserSubprocess.exe");
            settings.LocalesDirPath = Path.Combine(cefFolder, "locales");
            settings.ResourcesDirPath = cefFolder;

            // Make sure you set performDependencyCheck false
            Cef.Initialize(settings, performDependencyCheck: true, browserProcessHandler: null); // Final exception is thrown here
        }
    }
}

我设置了BrowserSubprocessPath，LocalesDirPath，ResourcesDirPath，这似乎解决了大多数运行时错误，但是现在我遇到了这个模糊的异常：

System.IO.FileNotFoundException：'无法加载文件或程序集'CefSharp，版本= 73.1.130.0，区域性=中性，PublicKeyToken = 40c4b6fc221f4138'或其依赖项之一。系统找不到指定的文件。'

我肯定知道所有依赖项都在build文件夹中，并且我可以顺利运行CefSharp.MinimalExample项目。似乎都指向正在使用的卷影复制程序集（如果我不覆盖设置中的BrowserSubprocessPath，则可以看到它最初指向C:....\AppData\local\assembly\some\long\temp\path）。

启用程序集卷影副本时出现FileNotFound异常

0 个答案: