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Hi Tina,
you would delete a file using File.Delete() assuming it is not in use; so your program must first close it if it has opened it earlier.
A FileSystemWatcher is fine for acting (almost immediately) on file system events, however if you want your action to occur periodically (e.g. once a day at a fixed time) it does not make sense to use a FSW and to have a process lingering around; just schedule your app and use Directory.GetFiles() then.
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Anyone tried exposing, say, a stock price update service (i.e. Price Feed), via Remoting as supposed to traditional tried and true Socket based communication?
Is Remoting fast enough? Viable alternative?
dev
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Hellow dev,
according my knowledge u should go for remoting instead of sockets. Ofcourse u can implement it thorough sockets as well as remoting but remoting gives u more flexibility. Remoting can also handle multiple calls so better is to use remoting.
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This is for a client server application where
scenario: 5000 x 3 updates/min --> 15k updates per min per client
Each update comes from server, published/push to subscribers on client workstation over corporate intranet. You done remoting in situation similiar to this? Is it fast enough?
I don't think encryption is relevant as this need to be done (optionally) whether remoting or over socket.
dev
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hi,
i want 2 know that ..i gave 20 min for session expire ..if session is expired if i click and field its go to login page ..plzz can u send me code for that .. or else plzz guide me then i can do it..
Some Thing need 2 do NEW
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You could look into the SlidingExpiration property.
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Hello guys.
Can we create C#.Net Application for Symbian OS ?
Is it possible ?
Thank you.
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I may be mistaking, but I think there is only the MONO implementation that makes it possible to run the .Net framework on a Linux/Unix machine (and therefore also Mac I presume), and it supports only the versions 1, 1.1 and 2.0 of the framework currently. This is really a gigantic work and it is not done by Microsoft, I don't think it is possible.
Jean-Christophe Grégoire
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It does not make the .NET Framework run on Linux. The ".NET Framework" is Microsoft's implementation of the Common Language Infrastructure specification. Mono is an open source implementation of the same spec. The two are "kind of" compatible, but Mono is not a one-for-one replacement for .NET, nor is it a tool to run a .NET app on Linux.
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I don't know if Mono[^] runs on Symbian, you may want to take a look at this site.
regards
modified 12-Sep-18 21:01pm.
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Hello everybody,
I created a bitmap, 10 x 10 points, where each point has different color, using LockBits, and UnlockBits. Now I want to display it on a form, but on bigger scale. I used for this
Bitmap bmp = new Bitmap(10, 10, PixelFormat.Format24bppRgb);
Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height)
…
Here I put some data to my bitmap
…
Rectangle newRect = new Rectangle(0, 0, 100, 100);
g.DrawImage(bmp, newRect, rect, GraphicsUnit.Pixel);
As a result my image on a screen looks like this: first colomn displays half width and first row dysplays half width. All the rest looks normal. Could you please help me figure out how to fixed this?
Thank you in advance
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Hi,
I have encountered similar effects; it is probably due to a "nearest neighbour" interpolation, which can be compensated for by shifting the coordinate system over half a pixel (fortunately GDI+ uses floating point coordinates). I don't recall the details on how to do exactly that, but you got the picture...
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Additionally to what Luc said, you can also try to change the InterpolationMode property of the Graphics object. I don't see an enum value for turning it off, though, maybe Low will help.
regards
modified 12-Sep-18 21:01pm.
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I tried to set
Graphics g = this.CreateGraphics();
g.InterpolationMode = InterpolationMode.NearestNeighbor;
differenct mode and only NearestNeighbor gave me clear pixels as squares, all the rest creates some bluring images.
Thanks
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Member 1980999 wrote: differenct mode and only NearestNeighbor gave me clear pixels as squares
Yeah, this may be the right one for you. NearestNeighbour doesn't invent any new colors but just interpolates from existing ones, so no blurring in this case.
modified 12-Sep-18 21:01pm.
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Hi,
there is no OFF position, a scaling algorithm needs some way to decide what pixel to use.
all but NearestNeighbor calculate new pixels, i.e. perform real interpolation, which normally is good,
but may ruin a synthetic image like yours.
NearestNeighbor copies an existing pixel, it is like rounding real coordinates to integer ones.
unfortunately the one you want is not provided; it could be called LeftNeighbor, corresponding to
rounding down, i.e. the floor function. However a shift by 0.5 turns NearestNeighbor into LeftNeighbor.
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Hi all.
I've had a DataBase[^] that named Database1.mdf
After that VS2008 SP1 creates a DataSet in my Project, named Database1DataSet
Then I've created a TableAdapter[^].
Now I wanna update the DataBase with them ( DataSet & DataTable & TableAdapter ).
I used this code :
Database1DataSetTableAdapters.eventsTableTableAdapter eventsTableTableAdapte =
new WpfApplication1.Database1DataSetTableAdapters.eventsTableTableAdapter();
Database1DataSet.eventsTableDataTable eventsTableDataTable =
new Database1DataSet.eventsTableDataTable();
eventsTableTableAdapte.Fill(eventsTableDataTable);
var id = (from c in eventsTableDataTable.Distinct()
select c.id).Last();
id++;
DataRow newDataRow = eventsTableDataTable.NewRow();
newDataRow["event"] = "event" + id.ToString();
newDataRow["date"] = id;
eventsTableDataTable.Rows.Add(newDataRow);
eventsTableTableAdapte.Update(eventsTableDataTable);
eventsTableTableAdapte.Dispose();
eventsTableDataTable.Dispose();
But the changes not apply to the DataBase , Why ?
What's wrong with it ?
Many thanks in advance.
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Lets say I have a hypothetical class which does something and upon error throws exception as below:
public class Do
{
void DoSomething()
{
// do a few things
// do a few more things
if (SomethingWrong())
throw // some exception here
}
}
I understand I have the option to either create my own custom exception, throw the exception, or simply create a new Exception object and add my own message to it and link the inner exception to it.
My question is which of the above option is more ideal? Or should I throw ApplicationException?
Also in client code, which of the following is a better programming habit:
try
{
SomethingWhichCanThrowExceptionA();
SomethingWhichCanThrowExcepitonB();
// Some code here which does things and will not throw exception
}
Catch(ExceptionA)
{
// Recover
}
Catch(ExceptionB)
{
// Recover
}
Or:
try
{
SomethingWhichCanThrowExceptionA();
SomethingWhichCanThrowExceptionAPassed = true;
}
Catch(ExceptionA)
{
// Recover
}
if (SomethingWhichCanThrowExceptionAPassed)
{
try
{
SomethingWhichCanThrowExcepitonB();
SomethingWhichCanThrowExceptionBPassed = true;
}
}
Catch(ExceptionB)
{
// Recover
}
if (SomethingWhichCanThrowExceptionAPassed && SomethingWhichCanThrowExceptionBPassed)
{
// Some code here which does things and will not throw exception
}
Please shed some light on this or provide your own suggestions and how you do things.
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Hi,
IMO and unless a pre-existing Exception type fits the bill accurately (as in NullReferenceException),
you should create your own Exception type, give it an appropriate name ending on "Exception" and
derive it directly or indirectly from Exception or better yet ApplicationException; even do consider a hierarchy of Exceptions.
The advantage is you (and the users of your class) can then catch your new exception type(s) without
catching more global Exceptions.
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But if all I am doing is simply reporting a message with a more friendly message, does it make sense to create custom exceptions? For example,
RetrieveStudent(string id)
{
// Do a few things
if (Error)
throw new Exception("Failed to retrieve the student with id " + id);
}
And what about the 2nd question I had?
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CodingYoshi wrote: simply reporting a message with a more friendly message
even then, it is good practice; it is up to you to decide whether you value the precise catching it allows.
CodingYoshi wrote: 2nd question
the latter: separate try-catch constructs offer better isolation, better readability.
in the former, if you want B to happen even when A fails, your recovery code in the catch block would have to duplicate some code from the try block, which is bad.
ultimately you could consider putting each of the try-catches in a separate method.
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Exception handling is by definition about HANDLING an exception. When you want to display a friendly message, you are not handling anything. Handling an exception is for example retrying a connection to a remote machine after a timeout exception. This is real exception handling. Another form of exception handling is finding an alternative in case of disk I/O problem... writing on another disk or requesting the user to free some space for example.
Any other thing that you might want to do, like logging or displaying a message, should be placed at one single location within your application, potentially the application controller. This "application host" component (it can be your Program.cs as well...) is supposed to do something (log, display a popup, exit the application or close the form, or whatever you think may be appropriate). But it can terminate as well, it is up to you to decide when your application is stable, and when it is not.
Exception handling means what it says, you handle an exception when you can do something with it, otherwise you leave it going up the stack till it reaches the entry point.
JC
Jean-Christophe Grégoire
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