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Alan Balkany wrote: For a more realistic spinning roulette wheel (even on a slow system) use blurred intermediate images. These will give an appearance more like what a person would actually perceive seeing a real wheel spinning. Transition to actual images as the wheel slows down.
This sounds like a very interesting idea, however, I would not have a clue where to start by doing this. Would you possibly be able to provide a little more information please?
Thank you,
Regards,
Stephen
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This http://www.blackpawn.com/texts/blur/default.html[^] gives basic blurring algorithms, but they're rectangle-oriented, and you need to adapt them for rotation.
So, instead of averaging in a rectangular region for each pixel, you'd use an arc representing a fraction of the roulette wheel's rotation, at the pixel's distance from the center +/- a delta constant.
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Thank you,
I will look into this.
Regards,
Stephen
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I want to compare 2 lists
i should get result if any of their property matches
I have this code
var list1 = new List<Emp>();
var list2 = new List<Emp>();
list1.Add(new Emp { Empname = "nitin", ID = 1 });
list2.Add(new Emp { Empname = "nitin", ID = 1 });
list2.Add(new Emp { Empname = "nitin", ID = 1 });
list2.Add(new Emp { Empname = "Sean", ID = 3 });
foreach(var p in list1.Count()>list2.Count() ? list2:list1 )
{
var u=list2.Where(x => x.ID == p.ID || x.Empname == p.Empname );
}
This works fine but results are displayed twice it should be only one. currently i get {nitin,1} twice in u.
where is the issue.
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Don't use Linq, and break after the first match.
Or maybe use distinct? Is there one?
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That's what the selection on list2 will give. (Think about it for a moment.)
What you want is something along the lines of
var matches = list1.Where(x => list2.Contains(x));
Since you apparently want a value comparison you should override Equals (and maybe == too) on Emp. That would test that all the properties matched (and I think it would make Contains work in the above expression).
If you really want to check that any of the properties match, you need to write a Contains equivalent (it's a one line LINQ expression). But that seems unlikely.
Ideally you'd be using the same actual object for what appears to be a reference to the same database row, but if it's actually coming out of a database provider that may not be possible. Classes that represent database entities often want value semantics for equality (unless you're using some clever entity management framework that gives you the same instance for the same row).
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Just use a First query on the end of your Where query like this
foreach(var p in list1.Count()>list2.Count() ? list2:list1 )
{
var u=list2.Where(x => x.ID == p.ID || x.Empname == p.Empname ).FirstOrDefault();
}
and that will return the first such emp. I use FirstOrDefault() in case there are no matches it will return a null Emp instead of throwing an Exception if there are no matches.
You need to look out if List2 is longer than List1 as you will then be matching List2 to List2 here list2.Where.
Hope this helps
When I was a coder, we worked on algorithms. Today, we memorize APIs for countless libraries — those libraries have the algorithms - Eric Allman
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Since you are adding Emp{Empname="nitin", ID=1} twice I guess finding it twice in your foreach shouldn't be that much of a surprise.
I would use intersect. That means implementing IEquatable for your class (and perhaps GetHashCode).
Like this:
class Emp : IEquatable<Emp>
{
public string Empname { get; set; }
public int ID { get; set; }
#region IEquatable<Emp> Members
public bool Equals(Emp other)
{
if (Object.ReferenceEquals(other, null)) return false;
if (Object.ReferenceEquals(other, this)) return true;
return ID == other.ID &&
Empname.Equals(other.Empname);
}
#endregion
public override int GetHashCode()
{
return Empname == null ? 0 : Empname.GetHashCode()^
ID.GetHashCode();
}
}
And then use it as:
var u = list2.Intersect(list1);
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Hi,
In my windows application i am using file dialog box for uploading the file. If the file is in use i am not able to upload its giving exception.
How can i solve it,i mean to say if still the file is in use i want to upload it.
Can any one suggest me how can i do it ?
Thanks in advance.
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If another application has the file open, and locked for reading, you cannot read from it. That's an OS level restriction. You can give yourself a chance by requesting a read-sharable lock to the file yourself:
FileStream fs = File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.Read);
This will succeed where an attempt to open the file read/write won't if another application has done the same thing. However, most applications lock files completely while in use (and some, notably MS Office, keep the file locked while it is open ... bad practice, that), and there is simply no way to read such a file while the other application has it open.
Check that your own application isn't opening a file and forgetting to close it, though. That's a good way of creating this exception that can be fixed. You can generally put a FileStream or StreamReader in a using block which makes sure it is always closed.
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thanks it helped me a lot.
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BobJanova wrote: This will succeed where an attempt to open the file read/write won't if another application has done the same thing. However, most applications lock files completely while in use (and some, notably MS Office, keep the file locked while it is open ... bad practice, that), and there is simply no way to read such a file while the other application has it open.
I don't agree on you that it is bad practice. If MS Word is doing intermittent writes to it and share it for reading, then another application reading the file could get strange results, where the first half of the file is 'old' and the second half is 'new'. Locking files (appropriately) while in use is a good thing.
Consider a user deleting a file, and it keeps coming back. "Why is this happening?!". Because the application that is writing to the file doesn't have it locked, so at every write it comes back*. With locks, the user gets the immediate error that the file is in use.
The lock is there because the file is in use, and access to it can't reasonably work properly, so it is protecting other applications.
* slightly fictional situation, but it is a good example of why files have locks
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The file should be locked against reading when it is actually being written. In a document editing app, that should be the time between pressing 'Save' and the save completing. There's no reason for a program like Word (or Adobe Reader, lest ye think I'm just being anti-Microsoft) to hold the file open the entire time you are looking at it.
The basic point I'm trying to make is that yes, locks are for when the file is in use. Once a document is loaded, it is in memory and the file shouldn't be in use; you should be able to open, delete, edit it etc in another editor (as you can with text editors, image editors etc) while it is being viewed in one editor.
This is kind of a tangent but I don't mind because I think the OP already got a good answer.
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BobJanova wrote: There's no reason for a program like Word (or Adobe Reader, lest ye think I'm just being anti-Microsoft) to hold the file open the entire time you are looking at it
Writing to a text-file is not an atomic operation. Having people read incomplete information might result in bugs that are hard to track.
Bastard Programmer from Hell 
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I don't think I can have explained this well. It is absolutely correct that, while the file is being saved, it is locked. What these programs do is lock the file the whole time you are looking at it (i.e. not just when it's updating the file).
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Yes. Word locks the file, and keeps a temporary copy - the file is being edited, and cannot be saved in between. It might take 30 minutes to update the file.
Time for me to get some sleep, I guess I'm missing the point here 
Bastard Programmer from Hell
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BobJanova wrote: The file should be locked against reading when it is actually being written. In a document editing app, that should be the time between pressing 'Save' and the save completing.
You make a very valid point there. However, the implementation holds some problems and I guess that's why it is the way it is now. I'm thinking that if Word would do that, and another program decides to start reading from the file (thus locking it temporarily for writes), any save or write from Word would have to wait until the other program releases its lock. Now, if it is a well behaved program, this might only take a few seconds, but then still, it adds a few seconds to any file write, which can be annoying. This problem you could work around by the OS caching the writes (or the reads) of the other program.
Now, suppose the other program is not so well behaved and keeps the read lock for minutes. Then we have Word hanging, or if it's cached the responsibility of the OS to keep all changes to the file cached for a very long time.
Well, I guess that it could work if the OS supported it. But only then. As it is now, any program that would try to be 'friendly' and release the lock between writes would become very vulnerable to IO-blocking by other programs. It could be done maliciously, for instance, to indefinitely halt execution of an application.
It is indeed a tangent, but I find it interesting to think about the possibilities
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Hi.
Can anyone tell me why when i compile same code in Framework 4.0 target and 2.0, in 4.0 small count of videos can be played, in 2.0 all available formats are being played and captured correctly.
What's the point of that ?
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None, and the problem is too vague to answer. Do you have any code that can be used to replicate the problem?
Bastard Programmer from Hell
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There's a forum at the bottom of that[^] page; if you post a question there, the author of the article will get an email.
To answer the question; I guess there's a difference in the versions of DirectX installed.
Bastard Programmer from Hell
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Hi all ! I have that code below:
How can i connect the graph and IBasicVideo to NullRenderer ? I have it already working but with IVideoWindow, how to use NullRenderer instead of IVideoWindow and get the same results ?
Thanks in advance!
BTW: Sorry for my english
private void BuildGraph(){
int hr = 0;
this.graphBuilder = (IGraphBuilder)new FilterGraph();
hr = this.graphBuilder.RenderFile(filename, null);
DsError.ThrowExceptionForHR(hr);
this.mediaControl = (IMediaControl)this.graphBuilder;
this.mediaEventEx = (IMediaEventEx)this.graphBuilder;
this.mediaSeeking = (IMediaSeeking)this.graphBuilder;
this.mediaPosition = (IMediaPosition)this.graphBuilder;
this.videoWindow = this.graphBuilder as IVideoWindow;
this.basicVideo = this.graphBuilder as IBasicVideo;
hr = this.mediaEventEx.SetNotifyWindow(myOwnerPanelHandle.Handle, WMGraphNotify, IntPtr.Zero);
DsError.ThrowExceptionForHR(hr);
hr = this.videoWindow.put_Owner(myOwnerPanelHandle.Handle);
DsError.ThrowExceptionForHR(hr);
this.videoWindow.put_AutoShow(OABool.False);
hr = this.videoWindow.put_WindowStyle(WindowStyle.Child | WindowStyle.ClipSiblings | WindowStyle.ClipChildren);
DsError.ThrowExceptionForHR(hr);
hr = InitVideoWindow(1, 1);
DsError.ThrowExceptionForHR(hr);
#if DEBUG
rot = new DsROTEntry(this.graphBuilder);
#endif
hr = this.mediaControl.Run();
DsError.ThrowExceptionForHR(hr);
hr = this.mediaControl.Pause();
DsError.ThrowExceptionForHR(hr);
hr = mediaPosition.get_Duration(out Duration);
DsError.ThrowExceptionForHR(hr);
hr = basicVideo.get_VideoHeight(out pVideoHeight);
DsError.ThrowExceptionForHR(hr);
hr = basicVideo.get_VideoWidth(out pVideoWidth);
DsError.ThrowExceptionForHR(hr);
}
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What is not working? A null renderer just discards all the input it receives (so nothing is drawn to the screen).
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It's drawn into ActiveMovie window how to hide this window ?
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I'm not the best person to help you with this, I'm afraid, but:
You're going to have to replace the video renderer with the null renderer.
Maybe this article can help you? http://msdn.microsoft.com/en-us/library/dd407299(v=vs.85).aspx[^]
It implies that if you first create an instance of the null renderer, add it to the graph and then call RenderFile that the graph builder will use the null renderer instead of the default one.
Otherwise, you are going to have to examine the built graph and search for the video renderer and replace that.
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