我一直在使用的一个应用程序在尝试序列化类型时失败了。

像这样的陈述

XmlSerializer lizer = new XmlSerializer(typeof(MyType));

生产:

System.IO.FileNotFoundException occurred
  Message="Could not load file or assembly '[Containing Assembly of MyType].XmlSerializers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified."
  Source="mscorlib"
  FileName="[Containing Assembly of MyType].XmlSerializers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
  FusionLog=""
  StackTrace:
       at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
       at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)

我没有为我的类定义任何特殊的序列化器。

我该如何解决这个问题?


当前回答

另一方面,对编译错误进行故障排除是非常复杂的。这些问题在FileNotFoundException异常中显示,并显示如下信息:

File or assembly name abcdef.dll, or one of its dependencies, was not found. File name: "abcdef.dll"
   at System.Reflection.Assembly.nLoad( ... )
   at System.Reflection.Assembly.InternalLoad( ... )
   at System.Reflection.Assembly.Load(...)
   at System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly() 

You may wonder what a file not found exception has to do with instantiating a serializer object, but remember: the constructor writes C# files and tries to compile them. The call stack of this exception provides some good information to support that suspicion. The exception occurred while the XmlSerializer attempted to load an assembly generated by CodeDOM calling the System.Reflection.Assembly.Load method. The exception does not provide an explanation as to why the assembly that the XmlSerializer was supposed to create was not present. In general, the assembly is not present because the compilation failed, which may happen because, under rare circumstances, the serialization attributes produce code that the C# compiler fails to compile.

请注意 当XmlSerializer在不能访问临时目录的帐户或安全环境下运行时,也会发生此错误。

来源: http://msdn.microsoft.com/en-us/library/aa302290.aspx

其他回答

此异常也可以由名为BindingFailure的托管调试助手(MDA)捕获。

如果您的应用程序被设计为附带预构建序列化程序集,则此MDA非常有用。这样做是为了提高应用程序的性能。它允许我们确保预先构建的序列化程序集由构建过程正确构建,并由应用程序加载,而无需动态重新构建。

除了在这种情况下,它实际上没什么用,因为正如其他帖子所说,当绑定错误被Serializer构造函数捕获时,序列化程序集将在运行时重新构建。所以你可以把它关掉。

我的解决方案是直接使用反射来创建序列化器。这就绕过了导致异常的奇怪文件加载。我将其打包在一个helper函数中,该函数还负责缓存序列化器。

private static readonly Dictionary<Type,XmlSerializer> _xmlSerializerCache = new Dictionary<Type, XmlSerializer>();

public static XmlSerializer CreateDefaultXmlSerializer(Type type) 
{
    XmlSerializer serializer;
    if (_xmlSerializerCache.TryGetValue(type, out serializer))
    {
        return serializer;
    }
    else
    {
        var importer = new XmlReflectionImporter();
        var mapping = importer.ImportTypeMapping(type, null, null);
        serializer = new XmlSerializer(mapping);
        return _xmlSerializerCache[type] = serializer;
    }
}

Martin Sheburn最初的回答是正确的。 来自edeboursetty, tomas-kubes)的代码示例,quadfinity应该解决在调试器中不引发过量异常的问题。

这里有一个简短的解决方案:

internal sealed static class XmlSerializerHelper
{
    private static readonly ConcurrentDictionary<Type, System.Xml.Serialization.XmlSerializer> s_xmlSerializers = new();

    public static System.Xml.Serialization.XmlSerializer Get<T>()
    {
        return s_xmlSerializers.GetOrAdd(typeof(T), _ => System.Xml.Serialization.XmlSerializer.FromTypes(new [] {typeof(T)})[0]);
    }
}

我得到了同样的错误,这是由于我试图反序列化的类型没有默认的无参数构造函数。我添加了一个构造函数,它开始工作了。

在Visual Studio项目属性(“Build”页面,如果我没记错的话)中有一个选项显示“生成序列化程序集”。尝试为生成[包含MyType的程序集]的项目打开该选项。