如何将Marshal.SizeOf(Object)替换为Marshal.SizeOf< T>()? [英] How can I replace Marshal.SizeOf(Object) with Marshal.SizeOf<T>()?

问题描述

我正在从现有代码中构建一个 Universal 类库，并且收到一些编译器警告，提示我一生都无法解决该问题.

I am building a Universal class library from existing code, and I get some compiler warnings that I for the life of it cannot figure out what to do with.

我有这样的代码:

void SomeMethod(Object data)
{
  var size = Marshal.SizeOf(data);
  ...
}

代码已构建，但是在 Universal 项目(我猜是.NET 4.5.1和更高版本的项目)中，我收到以下编译器警告:

The code builds, but in the Universal project (and, I guess, .NET 4.5.1 and higher projects) I get the following compiler warning:

警告CS0618:"System.Runtime.InteropServices.Marshal.SizeOf(object)"已过时:"SizeOf(Object)在将来的版本中可能不可用.而是使用SizeOf< T>().

warning CS0618: 'System.Runtime.InteropServices.Marshal.SizeOf(object)' is obsolete: 'SizeOf(Object) may be unavailable in future releases. Instead, use SizeOf<T>().

但是在上述情况下，如何使用通用的无参数方法Marshal.SizeOf<T>()为Marshal.SizeOf(Object)创建替换?从理论上讲，我可能不知道data是什么类型?

But how do I create a replacement for Marshal.SizeOf(Object) in the above case using the generic parameter-less method Marshal.SizeOf<T>()? Theoretically, I might not have any idea what type data is?

是因为使用Marshal.SizeOf(Object)被归为Obsolete被认为是不好的做法吗?带回家的消息真的应该是完全重构代码"吗?

Is it because using Marshal.SizeOf(Object) is considered bad practice that it has been attributed Obsolete? And the take-home message should really be "refactor the code completely"?

推荐答案

好的，在收到您的评论后，看来您所需的一切已经存在:

Okay, after getting your comments it seems that everything you need is already there:

SizeOf<T>(T) : 我认为这是您需要的方法，但是由于

SizeOf<T>(T): I think this is the method you need, but you don't have to define the generic parameter explictly, due to type inference. You simple write var size = Marshal.SizeOf(myStructure); and the compiler will extract the type from the given object and fill out the generic parameter.

SizeOf<T>() : 当您自己的类可能已经是泛型类并且您具有T但没有所使用的泛型类型的实际实例时，此方法会派上用场.在这种情况下，应选择此方法.

SizeOf<T>(): This method comes in handy when your own class is maybe already a generic class and you have a T but no real instance of the used generic type. In that case this method should be choosen.

<罢工> 这种反射方法怎么样:

How about this reflection approach:

private static int MySizeOf(object structure)
{
    var marshalType = typeof(Marshal);
    var genericSizeOfMethod = marshalType.GetMethod("SizeOf", Type.EmptyTypes);
    var sizeOfMethod = genericSizeOfMethod.MakeGenericMethod(structure.GetType());
    var size = (int)sizeOfMethod.Invoke(null, null);

    return size;
}

这篇关于如何将Marshal.SizeOf(Object)替换为Marshal.SizeOf&lt; T&gt;()?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！