为什么我(有时)必须引用我引用的程序集所引用的程序集? [英] Why do I (sometimes) have to reference assemblies referenced by the assembly I reference?

问题描述

我有一个程序集 A，它定义了一个带有一些重载的接口:

I have an assembly A that defines an interface with some overloads:

public interface ITransform
{
    Point InverseTransform(Point point);
    Rect InverseTransform(Rect value);
    System.Drawing.Point InverseTransform(System.Drawing.Point point);
}

...以及引用 A(二进制文件，而不是项目)并调用其中一个重载的程序集 B:

...and an assembly B that references A (the binary, not the project) and calls one of the overloads:

var transform =
    (other.Source.TransformToDisplay != null &&
    other.Source.TransformToDisplay.Valid) ?
    other.Source.TransformToDisplay : null;
if (transform != null)
{
    e.Location = transform.InverseTransform(e.Location);
}

准确地说，它调用了InverseTransform 方法的System.Windows.Point 重载，因为这是Location 属性的类型> 在 e 中.

To be precise, it calls the System.Windows.Point overload of the InverseTransform method, because that is the type of the property Location in e.

但是当我在 IDE 中构建 B 时，我得到:

But when I build B in the IDE I get:

错误 CS0012:类型System.Drawing.Point"是在未引用的程序集中定义的.您必须添加对程序集System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"的引用.

error CS0012: The type 'System.Drawing.Point' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

即使这甚至不是我所说的超载.当我注释掉调用重载方法 InverseTransform 的行时，即使我仍在实例化 ITransform 类型的对象，它也能很好地构建.

even though that's not even the overload I am calling. When I comment out the line where the overloaded method InverseTransform is called, it builds fine even though I'm still instantiating an object of type ITransform.

为什么?有没有办法解决这个问题，而不必在任何地方添加对 System.Drawing 的引用?

Why? And is there a way to fix this without having to add a reference to System.Drawing everywhere?

推荐答案

编译器需要知道 System.Drawing.Point 是什么，以证明它不是正确的重载(例如，如果它有一个隐式转换).

The compiler needs to know what a System.Drawing.Point is in order to prove that it's not the correct overload (eg, if it has an implicit conversion).

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