Microsoft .NET perguntas e respostas de entrevista
Pergunta 36. What is a destructor?
A C# destuctor is not like a C++ destructor. It is actually an override for Finalize(). This
is called when the garbage collector discovers that the object is unreachable. Finalize()
is called before any memory is reclaimed.
Pergunta 37. Can you use access modifiers with destructors?
No
Pergunta 38. What is a delegate?
A delegate in C# is like a function pointer in C or C++. A delegate is a variable that calls
a method indirectly, without knowing its name. Delegates can point to static or/and
member functions. It is also possible to use a multicast delegate to point to multiple
functions.
Pergunta 39. Write some code to use a delegate.
Member function with a parameter
using System;
namespace Console1
{
class Class1
{
delegate void myDelegate(int parameter1);
static void Main(string[] args)
{
MyClass myInstance = new MyClass();
myDelegate d = new myDelegate(myInstance.AMethod);
d(1); // <--- Calling function without knowing its name.
Test2(d);
Console.ReadLine();
}
static void Test2(myDelegate d)
{
d(2); // <--- Calling function without knowing its name.
}
}
class MyClass
{
public void AMethod(int param1)
{
Console.WriteLine(param1);
}
}
}
Multicast delegate calling static and member functions
using System;
namespace Console1
{
class Class1
{
delegate void myDelegate(int parameter1);
static void AStaticMethod(int param1)
{
Console.WriteLine(param1);
}
static void Main(string[] args)
{
MyClass myInstance = new MyClass();
myDelegate d = null;
d += new myDelegate(myInstance.AMethod);
d += new myDelegate(AStaticMethod);
d(1); //both functions will be run.
Console.ReadLine();
}
}
class MyClass
{
public void AMethod(int param1)
{
Console.WriteLine(param1);
}
}
}
Pergunta 40. What is a delegate useful for?
The main reason we use delegates is for use in event driven programming.
Mais uteis segundo os usuarios:
- Name 10 C# keywords.
- What is public accessibility?
- .NET Stands for?
- What is private accessibility?
- What is protected accessibility?