AntonariyСон Веры Павловныпропущено...
Вообще-то new как раз и предназначен, чтобы компилятор молчал.Вообще-то вот, что по этому поводу в MSDN написано:
https://docs.microsoft.com/en-us/dotnet/visual-basic/programming-guide/language-features/declared-elements/shadowing The main purpose of shadowing is to protect the definition of your class members. The base class might undergo a change that creates an element with the same name as one you have already defined. If this happens, the Shadows modifier forces references through your class to be resolved to the member you defined, instead of to the new base class element.
Да, только этот shadowing вполне делается и без new.
Вот код, с которого всё началось:
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class Program
{
static void Main()
{
ISpeak instance = new Foo();
instance.SayWord();
Console.WriteLine("done");
Console.ReadKey(true);
}
}
interface ISpeak
{
void SayWord();
}
class Bar: ISpeak
{
public void SayWord()
{
Console.WriteLine("i am a parent");
}
}
class Foo: Bar
{
public new void SayWord()
{
Console.WriteLine("i am a slave");
}
}
IL-код и метаданные метода Foo.SayWord:
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.method public hidebysig instance void SayWord() cil managed
{
// Размер кода: 13 (0xd)
.maxstack 8
IL_0000: nop
IL_0001: ldstr "i am a slave"
IL_0006: call void [mscorlib]System.Console::WriteLine(string)
IL_000b: nop
IL_000c: ret
} // end of method Foo::SayWord
TypeDef #4 (02000005)
-------------------------------------------------------
TypDefName: test2.Foo (02000005)
Flags : [NotPublic] [AutoLayout] [Class] [AnsiClass] [BeforeFieldInit] (00100000)
Extends : 02000004 [TypeDef] test2.Bar
Method #1 (06000006)
-------------------------------------------------------
MethodName: SayWord (06000006)
Flags : [Public] [HideBySig] [ReuseSlot] (00000086)
RVA : 0x00002094
ImplFlags : [IL] [Managed] (00000000)
CallCnvntn: [DEFAULT]
hasThis
ReturnType: Void
No arguments.
-------------------------------------------------------
Теперь убираем new:
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class Foo: Bar
{
public void SayWord()
{
Console.WriteLine("i am a slave");
}
}
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.method public hidebysig instance void SayWord() cil managed
{
// Размер кода: 13 (0xd)
.maxstack 8
IL_0000: nop
IL_0001: ldstr "i am a slave"
IL_0006: call void [mscorlib]System.Console::WriteLine(string)
IL_000b: nop
IL_000c: ret
} // end of method Foo::SayWord
TypeDef #4 (02000005)
-------------------------------------------------------
TypDefName: test2.Foo (02000005)
Flags : [NotPublic] [AutoLayout] [Class] [AnsiClass] [BeforeFieldInit] (00100000)
Extends : 02000004 [TypeDef] test2.Bar
Method #1 (06000006)
-------------------------------------------------------
MethodName: SayWord (06000006)
Flags : [Public] [HideBySig] [ReuseSlot] (00000086)
RVA : 0x00002094
ImplFlags : [IL] [Managed] (00000000)
CallCnvntn: [DEFAULT]
hasThis
ReturnType: Void
No arguments.
-------------------------------------------------------
- как говорится, найдите 10 отличий.
