接受2个lambdas的方法有问题

Question

我有以下课程:

    public class MyClass<T> where T : class
    {
         public void Method1<TResult>(T obj, Expression<Func<T, TResult>> expression)
         {
             //Do some work here...
         }

         public void Method2<TResult>(T obj, Expression<Func<T, TResult>> expression1, Expression<Func<T, TResult>> expression2)
         {
             //Do some work here...
         }
    }

我可以像这样调用Method1:

MyClass<SomeOtherClass> myObject = new MyClass<SomeOtherClass>();

myObject.Method1(someObject, x => x.SomeProperty);

但是当我尝试调用Method2时:

MyClass<SomeOtherClass> myObject = new MyClass<SomeOtherClass>();

myObject.Method2(someObject, x => x.SomeProperty, x => x.SomeOtherProperty);

我得到以下编译时错误:

Error 1 The type arguments for method 'MyClass.Method2<SomeOtherClass>.Method2<TResult>(SomeOtherClass obj, System.Linq.Expressions.Expression<System.Func<SomeOtherClass,TResult>>, System.Linq.Expressions.Expression<System.Func<SomeOtherClass,TResult>>)' cannot be inferred from the usage. Try specifying the type arguments explicitly. 

我怎样才能创建一个接受两个lambdas的方法并按照我的意图调用它？

Answer 1

做SomeProperty和SomeOtherProperty有相同的类型？如果没有,那就是你的问题,因为你正在使用一个TResult类型参数.

解决方案只是使用两个类型参数:

public void Method2<TResult1, TResult2>(T obj, Expression<Func<T, TResult1>> expression1, Expression<Func<T, TResult2>> expression2)
{
    //Do some work here...
}