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

信不信由你,这是正常行为。抛出一个异常,但由XmlSerializer处理,因此如果忽略它,一切都应该继续正常进行。

我发现这非常烦人,如果你搜索一下,会有很多抱怨,但据我所知,微软并不打算对此采取任何措施。

如果关闭特定异常的第一次机会异常,就可以避免在调试时一直弹出异常。在Visual Studio中,打开调试->异常(或按Ctrl + Alt + E),公共语言运行时异常->系统。IO -> System.IO.FileNotFoundException。

您可以在博客文章c# XmlSerializer FileNotFound异常(其中讨论了Chris Sells的工具XmlSerializerPreCompiler)中找到关于另一种方法的信息。

其他回答

看到过很多使用ConcurrentDictionary的建议,但没有可靠的例子,所以我将全身心投入到这个解决方案竞赛中。我不是一个线程安全的开发人员,所以如果这段代码不可靠,请为那些跟随的人说出来。

public static class XmlSerializerHelper
{
    private static readonly ConcurrentDictionary<Type, XmlSerializer> TypeSerializers = new ConcurrentDictionary<Type, XmlSerializer>();

    public static XmlSerializer GetSerializer(Type type)
    {
        return TypeSerializers.GetOrAdd(type,
        t =>
        {
            var importer = new XmlReflectionImporter();
            var mapping = importer.ImportTypeMapping(t, null, null);
            return new XmlSerializer(mapping);
        });
    }
}

我看过其他关于ConcurrentDictionary和Lazy加载值的文章。我不确定这是否与此相关,但这里是它的代码:

private static readonly ConcurrentDictionary<Type, Lazy<XmlSerializer>> TypeSerializers = new ConcurrentDictionary<Type, Lazy<XmlSerializer>>();

public static XmlSerializer GetSerializer(Type type)
{
    return TypeSerializers.GetOrAdd(type,
    t =>
    {
        var importer = new XmlReflectionImporter();
        var mapping = importer.ImportTypeMapping(t, null, null);
        var lazyResult = new Lazy<XmlSerializer>(() => new XmlSerializer(mapping), LazyThreadSafetyMode.ExecutionAndPublication);
        return lazyResult;
    }).Value;
}

在我的一个。net标准dll中也有类似的问题。

我使用了Microsoft.XmlSerializer.Generator nuget,它可以在. net Core和. net Standard上预生成XmlSerializer。

要序列化的自定义类:

[Serializable]
public class TestClass
{
    int x = 2;
    int y = 4;
    public TestClass(){}
    public TestClass(int x, int y)
    {
        this.x = x;
        this.y = y;
    }

    public int TestFunction()
    {
        return x + y;
    }
}

我已经附上了代码片段。也许这个能帮到你。

static void Main(string[] args)
{
    XmlSerializer xmlSerializer = new XmlSerializer(typeof(TestClass));

    MemoryStream memoryStream = new MemoryStream();
    XmlTextWriter xmlWriter = new XmlTextWriter(memoryStream, Encoding.UTF8);

    TestClass domain = new TestClass(10, 3);
    xmlSerializer.Serialize(xmlWriter, domain);
    memoryStream = (MemoryStream)xmlWriter.BaseStream;
    string xmlSerializedString = ConvertByteArray2Str(memoryStream.ToArray());

    TestClass xmlDomain = (TestClass)DeserializeObject(xmlSerializedString);

    Console.WriteLine(xmlDomain.TestFunction().ToString());
    Console.ReadLine();
}

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。

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