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how do i make the comboxitem isselected when i retrived back the data from database?
i tried as below
if reminder is 1 day , the comboxboxitem (reminder1) will be selected..
is this correct?
if (row["reminder"].ToString().Trim() == "1")
{
reminder_1.IsSelected = true ;
}
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Folowing is the code that is written in the console application.
what is the meaning of % displayString.Length
in the folowing line
Console.Write(displayString[counter++ % displayString.Length]);
class Program<br />
{<br />
static int counter = 0;<br />
<br />
static string displayString =<br />
"This string will appear one letter at a time. ";<br />
<br />
static void Main(string[] args)<br />
{<br />
Timer myTimer = new Timer(100);<br />
myTimer.Elapsed += new ElapsedEventHandler(WriteChar);<br />
myTimer.Start();<br />
Console.ReadKey();<br />
}<br />
static void WriteChar(object source, ElapsedEventArgs e)<br />
{<br />
Console.Write(displayString[counter++ % displayString.Length]);<br />
}<br />
}
If you have an apple & I have an apple and we exchange our apples, then each of us will still have only one apple but if you have an idea & I have an idea and we exchange our ideas, then each of us will have two ideas!
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% is modulus or the remainder you get with integer division. What you're doing here is keeping the index of the array within bounds for any value of count.
Regards,
Rob Philpott.
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How can i prevent user from deleting a file when the file is under use by another process ?
I have an application which creates a directory called (say) "Test" and creates a default "Text.xml" file in it.I dont want user to delete the "Test.xml" when the application is in use. what is the code for it.
Currently ,user can delete the file when application is open.
Please tell me the code for it...
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You can't delete an open file (well you might be able to if you fiddle around with permissions enough) so just keep the file open for the duration of your app.
This code:
[STAThread]
static void Main(string[] args)
{
FileStream fs = File.Open(@"C:\bobbins.txt", FileMode.Open);
Console.ReadLine();
fs.Close();
}
Prevents me from deleting the file bobbins.txt until my console app closes.
Regards,
Rob Philpott.
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Also I think there is a lock method for FileStream. Don't know it's efficiency.
"Legacy code" often differs from its suggested alternative by actually working and scaling.
—Bjarne Stroustrup
modified on Friday, March 14, 2008 7:10 AM
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Ah, not sure about that; never used it, but if so that sounds better!
Regards,
Rob Philpott.
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snoby wrote: How can i prevent user from deleting a file when the file is under use by another process ?
The file cannot be deleted while an application is using it. What is ... well part of Windows. Run an application and try to delete it ... you cant.
Other wise if I am not understanding you correctly, you can open the file for reading and only after the appliation has finished with the file, you can close the file.
something like ...
form onload()
open file for reading
form_onclose()
close file
Hope it helps ...
Regards,
The only programmers that are better that C programmers are those who code in 1's and 0's ![Green Alien | [Alien]](https://codeproject.freetls.fastly.net/script/Forums/Images/alien.gif)
 Programm3r
My Blog: ^_^
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What if want to be sure that no data is lost? Keeping a file opened could cause all data is lost on crush or immediate shut down.
I suppose that such construct could be used:
open file;
write data which shouldn't get lost;
close the file to save it; (*)
reopen it;
// ...
and so on.
But in could theoretically happen that user opens a file just after (*), before it's opened in the next command. The propability of this is near 0, anyway what to do then?
Greetings - Gajatko
Portable.NET is part of DotGNU, a project to build a complete Free Software replacement for .NET - a system that truly belongs to the developers.
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Just holding the file open won't do that. It's when you write data to the file without flushing it, or shut the machine off in the middle of a disk write that you run into this problem.
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I'm using TextWriter to create a .txt file. I'm using TextWriter.WriteLine() to write the string. Suppose my string is very huge say more than 100 characters then the few characters at the end are cut off. How can i determine the maximum no of characters i can store using WriteLine()? so that the remaining characters i can write in the next line?
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Hi,
Just a question ....
What happens when you make use of a StreamWriter ??
Regards,
The only programmers that are better that C programmers are those who code in 1's and 0's ![Green Alien | [Alien]](https://www.codeproject.com/script/Forums/Images/alien.gif)
 Programm3r
My Blog: ^_^
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I tried StreamWriter but it is the same problem the characters are truncated. Please help
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A code snippet would help, we can then see what you are trying to do and perhaps spot any fault
He who makes a beast out of himself gets rid of the pain of being a man
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Here is the code snippet
I have a huge string.
strVal= "1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz"
TextWriter tw = new StreamWriter(t.txt);
tw.WriteLine(strVal);
When i try to write this string to a text file it is cut off at the end.
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100 chars is fine. Megabytes is fine.
Are you sure your underlying stream is being flushed?
Regards,
Rob Philpott.
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Yes it is only writing 106 characters, the rest charaters are missed. Can we determine the max characters that could be written ?so that i dont miss out any character. Please let me know
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This console app:
[STAThread]
static void Main(string[] args)
{
using (FileStream fs = new FileStream(@"c:\output.txt", FileMode.Create, FileAccess.Write))
{
using (TextWriter t = new StreamWriter(fs))
{
t.WriteLine("0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789");
}
}
}
writes out 100 characters no problem.
Regards,
Rob Philpott.
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I'll bet my car keys you're not flushing the stream...
Regards,
Rob Philpott.
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You are right it works! Thanks
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Hi all,
I'm using a picturebox to display the images relaid from a Canon camara, and I have the following problem...
Each frame captured by the camara is dispayed within the picturebox. And when I try and use the Selection Control[^], I receive the following exception: Object is currently in use elsewhere.
Because of the following function (this function fires everytime a frame is received and thats about every couple of milliseconds):
void camera_ReceivedFrame(object sender, StreamEventArgs e)
{
comEnPiBox1.SourceImage = e.frame;
pictureBox1.Image = comEnPiBox1.SelectArea;
}
Any advice regarding this matter....
Many Thanks in advance
Regards,
The only programmers that are better that C programmers are those who code in 1's and 0's
Programm3r
My Blog: ^_^
modified on Friday, March 14, 2008 6:09 AM
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Sounds like a threading issue. Try using the lock statement. More info here[^]
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Hi,
Thanks for the reply, but if I use a lock on the picturebox and give exclusive right to the camara input, I will never be able to give the user seletion options on the picturebox. Cause the camara's frames are captured every couple of milli seconds.
You don't perhaps know of a control were a user can make a selection on a picturebox, while an input from a camara is refreshing the image within the picturebox?
Many thanks
Regards,
The only programmers that are better that C programmers are those who code in 1's and 0's ![Green Alien | [Alien]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/alien.gif)
 Programm3r
My Blog: ^_^
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Hi.
Well you don't have to use a lock statement on the picturebox itself: you can use a specially assigned locker object for that (there's more about it in the article I linked to in the previous post). The same goes for having a user make settings: You can have the user make any setting outside of the lock, shortly acquire it to apply the changed settings and then release it for your camera.
I have to say I really don't think the PictureBox control was meant for this kind of usage though. I'd look for a different approach, perhaps using DirectShow.
Hope this helps, cheers.
Standards are great! Everybody should have one!
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Thanks for the reply and the information
Regards,
The only programmers that are better that C programmers are those who code in 1's and 0's
Programm3r
My Blog: ^_^
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