有谁知道或不关心猜测为什么隐式类型仅限于局部变量？

  VAR啄=新的Foo（）;
 

但是，为什么不......

  VAR的getFoo（）{
    返回新的Foo（）;
}
 

解决方案

埃里克利珀做了关于这个问题的一个完整的博客文章。

在总结，主要的问题是，它会需要C＃编译器的一个主要的重新架构这样做。声明在一个单一的传球方式当前处理。这将需要多遍的，因为以形成推断变量之间的周期的能力。 VB.net大致有同样的问题。

Does anyone know or care to speculate why implicit typing is limited to local variables?

var thingy = new Foo();

But why not...

var getFoo() {
    return new Foo(); 
}

Eric Lippert did an entire blog post on the subject.

In summary, the main problem is that it would have required a major re-architecture of the C# compiler to do so. Declarations are currently processed in a single pass manner. This would require multiple passes because of the ability to form cycles between inferred variables. VB.net has roughly the same problem.