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when what you need is the value of N/D where N and/or D is a product, it helps to divide both N and D by some rather small value X.
in the current situation N is a product of a variable and a constant (N = bytesRead * 100), hence that constant 100 is the first candidate for X.
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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Hmmm... so (N/100)*100/(D/100) or (N/100)/(D/100)/100 ?
Maybe the OP should look into a checked scope...
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"divide both N and D by some rather small value X" is the math recipe.
Always think in the problem domain, then come up with the matching codes.
Applied on bytesReaded*100 with X=100 it means you don't need the multiplication in the numerator, as again you well know.
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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As the poster before said use an other type or do the div before the mul, because your program calculates right.
36257792 * 100 = 3.625.779.200 (int can only hold 2.1 billion!)
-> 3.625.779.200 -> cast to int =~ -669188096
-669188096 / 54444964 = -12,29109263...
cast to int = -12
so your program is totally right!
Greetings
Covean
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Yes I think I should use double, because if I div before mul then it may not show any progress at all if file size is small like 100 bytes. Anyway thanks for that info...
thanks others too, Eduard Keilholz and PIEBALDconsult
TVMU^P[[IGIOQHG^JSH`A#@`RFJ\c^JPL>;"[,*/|+&WLEZGc`AFXc!L
%^]*IRXD#@GKCQ`R\^SF_WcHbORY87֦ʻ6ϣN8ȤBcRAV\Z^&SU~%CSWQ@#2
W_AD`EPABIKRDFVS)EVLQK)JKQUFK[M`UKs*$GwU#QDXBER@CBN%
R0~53%eYrd8mt^7Z6]iTF+(EWfJ9zaK-iTV.C\y<pjxsg-b$f4ia> -----------------------------------------------
128 bit encrypted signature, crack if you can
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Xmen W.K. wrote: (bytesReaded * 100) / totalBytesToRead
when bytesReaded is of type int or less, the expression bytesReaded * 100 will be evaluated as int, which means the largest value it can have is Int32.MaxValue = some 2 billion. So for whenever bytesReaded exceeds some 20 million, the multiplication will overflow, resulting in a wrong value with a 50% probability of being negative.
Since you only want to know a percentage, the easiest solution is to use bytesReaded / (totalBytesToRead/100), however this expression will throw whenever totalBytesToRead<100;
a very good approximation would be bytesReaded / (1+totalBytesToRead/100)
Keep in mind my approximations may never reach 100 as the division will round down.
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
modified on Thursday, November 12, 2009 11:07 AM
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Oh, I hadn't seen this reply of yours until now.
I would add that, if (1+totalBytesToRead/100) doesn't vary, it can be calculated once rather than repeatedly:
int divisor = totalBytesToRead/100 ;
if ( divisor == 0 ) divisor = 1 ;
But as long as you're making a local variable to hold it, why not use a float (only two decimal places are required) and be done with it?
float divisor = totalBytesToRead/100.0F ;
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PIEBALDconsult wrote: why not use a float
because I am always hesitant to introduce reals when the end result I'm after is an integer.
But it would be all right here.
And now this begs the question: why is BackgroundWorker.ReportProgress() taking an int, as progress really is something that goes from 0.0 to 1.0?
and why is ScrollBar.Value an int? One often regrets it isn't either long or some real.
Maybe they too don't want to force reals on you when your app is all integer.
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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No idea. I also want NumericUpDown to be available with different types: NumericUpDown<int> or something.
Luc Pattyn wrote: progress really is something that goes from 0.0 to 1.0?
Well, can't it also go 0 to 54444964 ? And let .net handle the math?
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You are the only one who hit the nail in its head
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I'm a hammer at times. 
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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Anyway, I'm using ulong now, and I'm not calculating the years when a HDD will be made to overflow it.
BTW : Are you sure about your message title ? I thought we were friends 
TVMU^P[[IGIOQHG^JSH`A#@`RFJ\c^JPL>;"[,*/|+&WLEZGc`AFXc!L
%^]*IRXD#@GKCQ`R\^SF_WcHbORY87֦ʻ6ϣN8ȤBcRAV\Z^&SU~%CSWQ@#2
W_AD`EPABIKRDFVS)EVLQK)JKQUFK[M`UKs*$GwU#QDXBER@CBN%
R0~53%eYrd8mt^7Z6]iTF+(EWfJ9zaK-iTV.C\y<pjxsg-b$f4ia> -----------------------------------------------
128 bit encrypted signature, crack if you can
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Xmen W.K. wrote: Are you sure about your message title ?
I think so. It started with a false accusation and then took more than 20 messages to get to the root cause. Hasn't anyone seen overflows before?
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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Luc Pattyn wrote: It started with a false accusation
oh...your title have also false accusation. The Math is right, but int is unable to hold the value 
TVMU^P[[IGIOQHG^JSH`A#@`RFJ\c^JPL>;"[,*/|+&WLEZGc`AFXc!L
%^]*IRXD#@GKCQ`R\^SF_WcHbORY87֦ʻ6ϣN8ȤBcRAV\Z^&SU~%CSWQ@#2
W_AD`EPABIKRDFVS)EVLQK)JKQUFK[M`UKs*$GwU#QDXBER@CBN%
R0~53%eYrd8mt^7Z6]iTF+(EWfJ9zaK-iTV.C\y<pjxsg-b$f4ia> -----------------------------------------------
128 bit encrypted signature, crack if you can
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Wait a minute... Set the ProgressBar's Maximum to 54444964, set the Value to 36257792 (or whatever) and let the PB handle the math; it's going to anyway, you're just duplicating effort.
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Hold your horses.
In a few days/weeks/years, when the app starts dealing with really large files, with sizes that exceed Int32.MaxValue, the size variables will need to be Int64 all the way, and the PB cannot handle those anyway.
FWIW: what I tend to do is turn file sizes into kilobytes and ints, which "limits" them to 2TB (which is much larger than my largest partition).
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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We'll burn that bridge after we've crossed it.
Besides the OP's code is using ints and it doesn't say anything about files; just using ints and a ProgressBar.
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Hello, i have a default program .resx file it is named: form1.resx, i'd like to do allow change users the string value, i have 'First' string and it's value is 'One', i'm using this code to load the string from it:
this.components = new System.ComponentModel.Container();
System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1));
rValue = resources.GetString("First");
And it get's 'One' value, it's correct. So i'd like to change it by a program. I've tried
resources.ApplyResources("First", "Two"); but it won't work, any ideas? Thanks.
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String resources are compiled into string tables in the assembly. They are readonly and cannot be changed. If you wish to change strings at runtime, use custom settings file.
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Thought I would share what I learned yeasterday. Maybe some folks might enjoy my pain. 
I setup a text change event to exit a text box when the 17th character was entered. I automatically looks up a record in the database. The problem was the text box fired 4 times after the last character was entered.
I spent two hours tryinig to figure this out. I finally reached out to my teamates. Here is what I did.
When I built the form I added the text changed event to a textbox. I then "copied" the text box to several other text boxes (you guested it 3 other boxes).
Because the copy carried the rerefence to
Maybe this is a "newbee" mistake, but thought I would share.
Rudy
Somewhere between the grey (making sausage out of business rules) and the abstract (what is known and what is achieved) exists clarity and certainty.
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Rudy Steinhoff wrote: I spent two hours tryinig to figure this out.
This is the biggest newbie mistake in this. After about 30 minutes you should have been asking for help.
I know the language. I've read a book. - _Madmatt
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You are right, thanks for pointing out my mistake. Its good to get this kind of feedback. It makes me want to post to this forum again.
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No I do think, that trying to get a solution at your own is a better practice for a newbie.
If everybody would do the same, as the poster did, and uses some brain or at least google, then
there were not such a mass of users querying stupid questions in here!
If someone succeeds in querying for help, every time he spent more then 10 minutes on a problem
without solution, why should she/he learn how to solve problems on her/his own if he/she can ask someone?
Greetings
Covean
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Mark was being ironic. He's dealt with so many people that post as soon as they hit a problem, that having somebody like this was a refreshing change.
"WPF has many lovers. It's a veritable porn star!" - Josh Smith As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.
My blog | My articles | MoXAML PowerToys | Onyx
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Oh thanks for this information, I misunderstood him respectively not seen the ironic in it.
Greetings
Covean
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