将序列映射到数组时，Automapper返回对同一对象的引用 [英] Automapper returns reference to the same object when mapping sequences to arrays

问题描述

我有一个IEnumerable<T>的扩展方法，该方法映射序列项并返回一个克隆数组:

I have an extension method for IEnumerable<T>, which maps sequence items and returns an array of clones:

public static class AutoMapperExtensions
{
    public static T[] MapToArray<T>(this IEnumerable<T> sequence)
    {
        return Mapper.Map<T[]>(sequence);
    }
}

这是代码示例，从我的角度来看，其行为很奇怪:

Here's code sample, whose behavior is weird from my point:

        Mapper.CreateMap<SomeClass, SomeClass>();
        Mapper.AssertConfigurationIsValid();

        // clone list members and store them into array
        var list = new List<SomeClass>
        {
            new SomeClass { MyProperty = 1 },
            new SomeClass { MyProperty = 2 },
        };

        // works fine
        var array = list.MapToArray();

        // let's map array again
        var newArray = array.MapToArray();

        // ...and ensure, that new array was created;
        // this fails, because Automapper returns reference to the same array
        Debug.Assert(array != newArray); 

在我看来，最后的结果是错误的.正如我所期望的那样，该映射器将创建新的克隆数组，它只会将引用返回给同一数组.

It seems to me, that last result is wrong. While I'm expecting, that mapper will create new array of clones, it just returns the reference to the same array.

这是在其他地方记录的还是错误?

Is this documented elsewhere or this is a bug?

推荐答案

所以这不是一个错误-当AutoMapper看到两个可分配的对象时，它将简单地分配它们.如果要覆盖该行为，请在两种集合类型之间创建一个映射.

So this isn't a bug - when AutoMapper sees two objects that are assignable, it will simply assign them. If you want to override that behavior, create a map between the two collection types.

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