ATL Interview Preparation Guide
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ATL frequently Asked Questions in various Active Template Library (ATL) job Interviews by interviewer. Get preparation of ATL job interview

27 ATL Questions and Answers:

1 :: Tell me how do you like to go up in a swing?

it look fun going up and down in a swing

int a[][]=[4]
int [][]a=[4]?

Yes There is diff between, both will give you error. one
will give compiler error and another will give systax error.

3 :: What is proces?

In Windows, Thread is an unit of execution.Process is the
environment in which thread executes.Scheduler, schedules
the Threads not the process.
In Unix variants,Thread is treated as light weight process.
Scheduler, schedules the process not threads.

4 :: How to create SDK based ATL?
how to create SDK based COM?

Use the CAxWindow class as described below:
Make sure that AtlAxWinInit has been called.

5 :: What Is "AtlAxWin80"?

"AtlAxWin80" is the name of a window class that helps
provide ATL's control-hosting functionality. When you
create an instance of this class, the window procedure will
automatically use the control-hosting API to create a host
object associated with the window and load it with the
control that you specify as the title of the window. For
more information, see How Do I Load Controls Specified at
Run Time?.

6 :: What Is the ATL Control-Hosting API?

ATL's control-hosting API is the set of functions that
allows any window to act as an ActiveX control container.
These functions can be statically or dynamically linked
into your project since they are available as source code
and exposed by ATL80.dll. The control-hosting functions are
listed in the table below.

7 :: Which ATL Classes Facilitate ActiveX Control Containment?

ATL's control-hosting code doesn't require you to use any
ATL classes; you can simply create an "AtlAxWin80" window
and use the control-hosting API if necessary (for more
information, see What Is the ATL Control-Hosting API?).
However, the following classes make the containment
features easier to use.

8 :: How to Implement multiple dual interfaces?

We can implement a dual interface using the IDispatchImpl
class, which provides a default implementation of the
IDispatch methods in a dual interface. For more information
To use this class:

Define your dual interface in a type library.

Derive your class from a specialization of IDispatchImpl
(pass information about the interface and type library as
the template arguments).

Add an entry (or entries) to the COM map to expose the dual
interface through QueryInterface.

Implement the vtable part of the interface in your class.

Ensure that the type library containing the interface
definition is available to your objects at run time.

9 :: What are the known problems with the ATL 2.0 Object Wizard?

The ATL 2.0 Object Wizard might not be present in the
Component Gallery. The ATL 2.0 Object Wizard is not
installed by the main ATL 2.0 setup program (Atlinst.exe).
It requires a separate setup program. You need to download
and run the ATL 2.0 Object Wizard Technology Preview
(Objinst.exe) from the ATL Web page. There is a separate
ZIP file for Windows NT 3.51.

The ATL 2.0 Object Wizard may crash if an older version of
Oleaut32.dll is installed on the system. Make sure the
version of Oleaut32.dll is at least 2.20.4049. The latest
version is available for download at the Internet Explorer
3.x Web site. If this does not fix the problem, then
install Service Pack 2 for Windows NT 4.0.

10 :: What problems might be encountered when using _ATL_MIN_CRT?
What causes the linker error that _main is unresolved during Release builds?

Because before calling _Main, program might be calling
other function which is needed to initialize the memebers
of the program. If that function calling fails, then it
throws so called linker error.