C＃-实现类型接口时，不允许我将“ this”作为类型返回

Question

I have this:

public class MyClass<T>:  IView
{
        public View View()
        {
            return this;
        }
        public void Render(ViewContext viewContext, System.IO.TextWriter writer)
        {
            // We should cycle though all supported controls and generate HTML for them.
            // What about the validation binding?

            typeof(T).GetFields().ToList<FieldInfo>().ForEach(x => writer.WriteLine(x.FieldType + " is called " + x.Name + "</br>"));           
        }  


}

I get an error that it cannot implicitly cast this to a View. When I attempt a cast it fails. Is there any way to do this? Why does it fail?

EDIT: View implementation added. I trimmed too much out of the class. I apologize for not posting enough.

Answer 1

MyClass<T> instances are not convertible to View . They are only convertible to IView . If you want to inherit from View class, you should just do that. Implementing a similarly named interface doesn't magically cause the class to inherit from the base type you need:

public class MyClass<T> : View { ... }

Answer 2

Any of these will work.

public class MyClass<T>:  IView
{
    public IView View()
    {
        return this;
    }   
}

Or

public class MyClass<T>:  IView
{
    public MyClass<T> View()
    {
        return this;
    }   
}

MyClass is not a View and cannot be returned as one as you try to do.

Answer 3

Please try this:

public class MyClass<T>:  IView
{
        public View View()
        {
            return (MyClass<T>) this;
        }   
}