如何将DLLImport与结构一起用作C#中的参数？

[StructLayout(LayoutKind.Sequential)]
public struct MyStruct
{
    public int field1;
    public int field2;
}

[DllImport("mydll.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern int MyExternalMethod(MyStruct myStruct);

MyStruct myStruct = new MyStruct();
myStruct.field1 = 1;
myStruct.field2 = 2;

int result = MyExternalMethod(myStruct);