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Many thanks.
Luc Pattyn [Forum Guidelines] [My Articles]
The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.
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Async or Overlapped I/O is the most efficient Socket I/O mechanism.
link[^]
The next step in scaling up the server is to use asynchronous I/O. Asynchronous I/O alleviates the need to create and manage threads. This leads to much simpler code and also is a more efficient I/O model. Asynchronous I/O utilizes callbacks to handle incoming data and connections, which means there are no lists to set up and scan and there is no need to create new worker threads to deal with the pending I/O.
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But every recorder has to be a separate recorder and also it's very time critical to answer back the status specially for retrying the unsuccessful connection and things like this.
Do you think it's going to be a great difference in performance?
I have tested my recorder with 100 threads and I think I'm loosing some bytes compared to lower count of threads, do you think it's possible? or I'm just thinking that it happens?
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1)How can i get the webcam resolution? not modify only obtain the resolution.
2) How can I print on the image from the webcam the time and the date?
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www.rentacoder.com
Please remember to rate helpful or unhelpful answers, it lets us and people reading the forums know if our answers are any good.
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Hi Guys. I have written a FileWatcher WindowsService which works fine. Now, I want to go a step further. I have written a Windows App that the guys are currently using to convert files with. I want to incorporate this into the WindowsService. What is the best way of doing this? Would it be adviseable for me to code the conversion stuff into the service in the FileSystemWatcher_Created Event? Is this even possible? I have searched and I can't find anything that would suggest that this is possible or how it can be done.
Has anybody done anything like this before? If yes how?
Thanks
Excellence is doing ordinary things extraordinarily well.
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I would write a second Service to do the conversion.
On my last job I had several Services; of which one ran reports of different types and another handled emailing the results to whoever needed them.
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And how would I start or call this from withing the current service? Sorry for asking, this is the first time I'm dabbling in WindowsServices.
Excellence is doing ordinary things extraordinarily well.
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Thanks EliotA but my Service is working fine. It is processing the file once it has been picked up that the file has been created that i am after.
Excellence is doing ordinary things extraordinarily well.
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You could use .NET remoting and set up an IPC channel.
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They would both be running all the time, they're Services.
In my case, I had the report runner insert a record to a database table telling the emailer what to do. On the next cycle, the emailer reads the record, sends the required emails, and (on success) deletes the record (on failure, the record gets marked as failed).
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I'm creating a c# .net windows application using Visual Studio 2005. On one of my forms, I've save a new record/row to my database. On this form, it also has a Open File Dialog component, which opens a picture, so that I can save the picture to the database. The problem occurs whenever I use this image in other form, i get the error ; can not find image
but if i stop running and run the program there is no error
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Chances are the image can be found, just not opened. If you use Image.FromFile, replace it with Image.FromStream, passing a FileStream object which represents the file. Don't forget to Dispose the FileStream when you're done
Alternatively, if the other form uses the image saved to the database, it may be a problem with your database access code; perhaps the image data only gets partially written?
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i solve the problem by putting openfileDialog restoreDirectoy = true
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Hello
I want to access peoplesoft from C#
for that it requires "PeopleSoft_PeopleSoft.tlb" COM component
In add reference dialog Box it is not available in VS2005 and VS2008
How can i get this "PeopleSoft_PeopleSoft.tlb" ?
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By paying them tens of thousands of dollars for a development kit?
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In all seriousness though...I was looking into that a few years ago...it depends what you want to do.
You can go directly to the backend database if you just need to retrieve record data without the business logic. If you need/want the business logic, there is a web service interface you can use. Whether or not you have access to the web service configuration utility depends on whether the organization bought the appropriate modules.
EDIT: oh...and about the DLL...I don't know what that's from...it might be included in their SDK...to join the developer program and get access to the SDK was $50,000 when I spoke to them a few years ago.
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Reference conversions: These are conversion from one reference type to another. Reference conversions, implicit or explicit, never change the referential identity of the object being converted. In other words, while a reference conversion may change the type of the reference, it never changes the type or value of the object being referred to.
can someone explain the above with examples, thanks.
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I'll have a go..
Reference types are things which are on the heap and 'referred to' by a reference.
So
Cat cat = new Cat();
Would give you a cat reference to a cat object (on the heap).
You could convert this to an object
object cat2 = cat;
So now cat 2 is considered an object, but still it's really a cat. You could cast it back again.
Does that make sense?
Regards,
Rob Philpott.
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Rob Philpott wrote: I'll have a go..
Reference types are things which are on the heap and 'referred to' by a reference.
So
Cat cat = new Cat();
Would give you a cat reference to a cat object (on the heap).
You could convert this to an object
object cat2 = cat;
So now cat 2 is considered an object, but still it's really a cat. You could cast it back again.
Does that make sense?
Ok...
Now i diverge a bit, what is the purpose of reference type?
Let's say, Cat extends from Animal.
U can have the following:
Animal x = new Animal();
Cat y = new Cat();
Animal z = new Cat();
Is z a Cat?
If both Animal and Cat have a method call talk();
and since z.talk() will be calling from Animal and not Cat,
how can z be consider a cat, when it can't talk like a Cat?
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Ok, this is all known as polymorphism and is the backbone of object oriented programming.
Firstly, the purpose of a reference type. They didn't exist in languages such as C++, you could create anything either on the heap or the stack, it was your choice. The rules in .NET are a bit more restrictive in that all reference types end up on the heap. It's the concept of maintaining a reference to a thing rather than the thing itself (which absolutely speaking isn't really correct). You can for example have two references to the same object instance. Try that with a value type and you could easily run into problems.
Animal z = new Cat();
Here you have an animal reference to a cat instance. When you call Talk(), whether Animal.Talk() gets called or Cat.Talk() gets called depends on whether that method has been marked as virtual.
If not virtual Animal.Talk() gets called, hopefully for obvious reasons. If the method is virtual however, the runtime will start working through something that used to be called a v-table (don't know what it is in .net) based on the type of the instance not the type of the reference. Cat.Talk() gets called.
This way you can implement Cat.Talk, Dog.Talk, Chicken.Talk, treat any of them as an animal, and call Talk() and it will get resolved to the correct method.
Regards,
Rob Philpott.
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Rob Philpott wrote: They didn't exist in languages such as C++, you could create anything either on the heap or the stack, it was your choice. The rules in .NET are a bit more restrictive in that all reference types end up on the heap.
Just to add to that, there is a very good reason for this. When items could be created on the stack, the C/C++ function was at liberty to generate a pointer to it (effectively a C# reference). This could then be passed outside the function even if the function ended and the stack was reset. You then had a pointer to valid memory, but that could be currently in use by some other function. Nasty bugs resulted!
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