C#, default parameter value for an IntPtr

问题

I'd like to use a default parameter value of IntPtr.Zero in a function that takes an IntPtr as an argument. This is not possible as IntPtr.Zero is not a compile time constant.

Is there any way I can do what I want?

回答1:

Somewhat unintuitive, to put it mildly, you get it by using the new operator:

    void Foo(IntPtr arg = new IntPtr()) { 
    }

That was for fun, you probably enjoy this one better:

    void Foo(IntPtr arg = default(IntPtr)) { 
    }

回答2:

Since IntPtr is a struct, you could use Nullable-of-T?

static void SomeMethod(IntPtr? ptr = null) {
    var actualPtr = ptr ?? IntPtr.Zero;
    //...
 }

来源：https://stackoverflow.com/questions/12999495/c-default-parameter-value-for-an-intptr