Empty Catch - C# Discussion Boards

Ajay.k_Singh25-Sep-07 0:43

25-Sep-07 0:43

Yes because in the previous code DrawToBitmap function of a particular Form was used, this will return image of only one form.

However if you have multiple Forms on screen and you want to take image of whole screen, you may try following code which uses CopyFromScreen function and it will return image of every thing which is on screen –

int wth, ht; //modify width and height as per need

wth= 1000;
ht= 900;

Bitmap bmp2=new Bitmap(wth,ht);

Graphics grp = Graphics.FromImage(bmp2);

Point x1=new Point();
Point x2=new Point ();

x1.X=0;
x1.Y=0;

x2.X=0;
x2.Y=0;

Size sz = new Size(wth, ht);

grp.CopyFromScreen(x1,x2,sz, CopyPixelOperation.SourceCopy);

This should give you what you want. Let me know the result Smile | :)

.

-Dave.

Dave Traister,
ComponentOne LLC.
www.componentone.com

Re: Save Form screen as jpg-file

anderslundsgard25-Sep-07 4:47

anderslundsgard

25-Sep-07 4:47

Result:

_____________________________

...and justice for all

APe

Equivalent of CStringArray in C#

Mushtaque Nizamani24-Sep-07 22:26

Mushtaque Nizamani

24-Sep-07 22:26

CStringArray
http://msdn2.microsoft.com/en-us/library/tddz3etf(VS.80).aspx[^]
Is there any equivalent of that in C#.

Best Regards,
Mushq

Mushtaque Ahmed Nizamani
Software Engineer
Ultimus Pakistan

Re: Equivalent of CStringArray in C#

Martin#24-Sep-07 22:32

Martin#

24-Sep-07 22:32

Hello,

I think System.Collections.Spezialized.StringCollection[^] is what you are looking for!

Hope it helps!

All the best,

Martin

Re: Equivalent of CStringArray in C# [modified]

Mushtaque Nizamani24-Sep-07 22:39

Mushtaque Nizamani

24-Sep-07 22:39

Martin# wrote:
Hope it helps!

Yes it did. Smile | :)

Thanks a bunch.

-- modified at 5:35 Tuesday 25th September, 2007

Best Regards,
Mushq

Mushtaque Ahmed Nizamani
Software Engineer
Ultimus Pakistan

Inheritance in C# (class + interface)

kaminem24-Sep-07 22:22

kaminem

24-Sep-07 22:22

Hi all,

I have a class which inherit from System.WindowsForm.UserControl and an interface (with a method named Update)

I want to implement the Update method of my interface and not the user control method

is there a way to do that ?

like in C++ void Interface::Update() ? D'Oh! | :doh:

Thanks in advance

Re: Inheritance in C# (class + interface)

Colin Angus Mackay24-Sep-07 22:55

Colin Angus Mackay

24-Sep-07 22:55

You can have two update methods.

public void Update()
{
    // This is the first version
}
 
public void IMyInterface.Update()
{
    // This is the second version
}

MyControl control = GetControl(); // Do what is needed to create the control

control.Update(); // This will call the first version

((IMyInterface)control).Update(); // This will call the second version

The version called depends on what you have a reference to. If you have a reference to the class or one of its bases then the Update() method will be called, if you have a reference to the interface the IMyInterface.Update() will be called.

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Empty Catch

Malcolm Smart24-Sep-07 22:04

Malcolm Smart

24-Sep-07 22:04

void DoThis()
{
   try
      {
       DangerousCall();
      }
   catch( MyExpectedException e )  //cool <-- I threw this in my DangerousCall method
   {
        //handle my exception here
   }
   catch ( Exception e1 ) // <-- not what I expected but caught anyway
   {
        //this wasn't expected, but report the contents of e1
   }
}

You can replace the catch all catch ( Exception e1 ) with a parameterless catch catch { ... }.

...snip...
   catch( MyExpectedException e )  //cool <-- I threw this in my DangerousCall method
   {
        //handle my exception here
   }
   catch  // <-- not what I expected but caught anyway
   {
        //ok - so what do I do here?  How do I know what failed?
   }

Why? What does this give you? Can you get any exception info?

I've done a test and you can't use catch (Exception e) with catch { } as the compiler knows that is already a catch all in there. Confused D'Oh! | :doh:

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

"This time yesterday, I still had 24 hours to meet the deadline I've just missed today."

Re: Empty Catch

pmarfleet24-Sep-07 22:16

pmarfleet

24-Sep-07 22:16

No. The error is caught, but you can't get any detail about it. It has the effect of suppressing the error.

All exceptions derive from System.Exception, so catch {Exception e} will catch all exceptions regardless of type. You should only use catch {} if you deliberately want to suppress an exception if it is raised.

Paul

Re: Empty Catch

Malcolm Smart24-Sep-07 22:22

Malcolm Smart

24-Sep-07 22:22

Thanks. So it effectively replaces Catch(Exception e) but gives you less information.

Why would you want to not know what caused a problem?

I understand why you want to swallow exceptions, not rethrow them, etc, I do it when interfacing to an external system which is up and down like a yo-yo, but I like to at least look at the exception to see why if failed, and then optionally log it.

Re: Empty Catch

Colin Angus Mackay24-Sep-07 22:33

Colin Angus Mackay

24-Sep-07 22:33

Malcolm Smart wrote:
Why would you want to not know what caused a problem?

Generally it is laziness. It is part of the anti-pattern known as try-catch-ignore.

However, there are "good" uses for it. And I put "good" in quotes because it stretches my incredulity a bit.

You could have used it in .NET 1.x before they had things like TryParse on DateTime and int to check if the parse operation completed successfully. You were probably not interested in why it went wrong, just that it did. TryParse just returns a boolean to say if the parsing failed or not.

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* Glasgow: db4o: An Embeddable Database Engine for Object-Oriented Environments, Mock Objects, SQL Server CLR Integration, Reporting Services ...

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Re: Empty Catch

pmarfleet24-Sep-07 22:35

pmarfleet

24-Sep-07 22:35

Malcolm Smart wrote:
Why would you want to not know what caused a problem?

I'm not saying that it is good practice to use it, only that the language supports it.

Paul

Re: Empty Catch

Guffa24-Sep-07 23:11

Guffa

24-Sep-07 23:11

That depends on if you are using framework 1 or 2.

In framework 1, the difference is that catch(Exception) catches .NET exception, while a parameterless catch catches all exceptions.

In managed code you can only throw exceptions that derive from System.Exception, but if you call unmanaged code it may throw any object as an exception.

If you need to handle all exceptions in framework 1, you should use both a catch(Exception) and a parameterless catch, so that you get all available information.

In framework 2, anything thrown that doesn't derive from System.Exception is wrapped inside a System.Runtime.CompilerServices.RuntimeWrappedException object, so there is no longer any use for a parameterless catch. To specifically catch unmanaged exceptions you use catch(RuntimeWrappedException), otherwise you can just use catch(Exception) to catch them too.

---
single minded; short sighted; long gone;

Re: Empty Catch

Scott Dorman25-Sep-07 3:59

Scott Dorman

25-Sep-07 3:59

Good explanation. I think that's the clearest one I've seen in a while.

Scott.

—In just two days, tomorrow will be yesterday.

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Re: Empty Catch

Guffa25-Sep-07 10:21

Guffa

25-Sep-07 10:21

Thanks.

---
single minded; short sighted; long gone;

Develop Outlook in C# Windows forms

senselva24-Sep-07 21:58

senselva

24-Sep-07 21:58

Hi,

I have a MS Outlook application developed in C#.net.

Now I want to access a users calendar in outlook and get the meetings
scheduled, mails send & receive, respond and send meeting requests, etc. In other
words anything that happens with calendering on Outlook desktop
client, I want to develop that in my .net application.

I guess there must be a way to talk to the back end server and retrieve
the info for seamless integration with any application. I mean
interfaces, functions or objects.

As you can see I have no clue how to go about it.

Any help will be highly appreciated.

Thanks in advance.
Senselva

Re: Develop Outlook in C# Windows forms

Corinna John25-Sep-07 0:56

Corinna John

25-Sep-07 0:56

Hi,
everything you need to know is on CDOLive:
http://www.cdolive.com[^]

____________________________________
There is no proof for this sentence.

Google Suggest feature with ASP.NET 2.0

jebin k24-Sep-07 20:39

jebin k

24-Sep-07 20:39

Hi,

How to create the Google Suggest feature with ASP.NET 2.0 using C#. Please help me with Sample code. Thanks in Advance

Jebin

Re: Google Suggest feature with ASP.NET 2.0

dengboo24-Sep-07 20:48

dengboo

24-Sep-07 20:48

Use the keywords "auto complete" in CP, and you will see tons of articles about feature like Google Suggest

---------------------------------
Believe what you saw!

Re: Google Suggest feature with ASP.NET 2.0

jebin k25-Sep-07 1:25

jebin k

25-Sep-07 1:25

Thanks.

ReportingService.GetReportParameters

amraouf24-Sep-07 20:18

amraouf

24-Sep-07 20:18

when i run the application (c#) to get the parameters list of the report ( sql2005.reporting service)
it shows an error:

=============================
"System.Net.WebException: The request failed with HTTP status 502: Proxy Error ( The ISA Server denied the specified Uniform Resource Locator (URL). ).
at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
at TFIReportClient.RPTWebReference.ReportingService.GetReportParameters(String Report, String HistoryID, Boolean ForRendering, ParameterValue[] Values, DataSourceCredentials[] Credentials) in ...."
=============================

so, what can i do?

Re: ReportingService.GetReportParameters

pmarfleet24-Sep-07 21:35

pmarfleet

24-Sep-07 21:35