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JoJuPi01 wrote: I want to display 4 images per rows and the rows must be calculated based on the number of images.
Divide the Collection.Count property by 4, and if there is no reminder then the result will be the rows count, otherwise the rows count will be the result + 1.
JoJuPi01 wrote: So i want to creat the rows and columns dynamically and load the images also dynamically. \
Try to do it by yourself and if there is any problem, just post a new thread here.
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"The Soapbox has been so ..."
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Currently, I am working on ZX2C4 Instant Messenger. ( http://zx2c4-im.sf.net ). For file transfers, a connection class raises an event for every 1024 bytes it receives (and finally length%1024 bytes at the end). This event is picked up by a form that has a progress bar.
Everytime the event is called, I make the progress bar's value maximumvalue * (bytes trasfered/total). However, I lack a good way to compute the number of kb/s at which the file is downloading.
Currently, when the progress bar is created, I assign a global varible called "start" to DateTime.Now, and every time the update event is signaled, I make the current speed equal to (bytes transfered) / (DateTime.Now - start).
While this works, it only provides the average speed of the whole download. What is the best way to calculate the current speed of the download?
Jason A. Donenfeld
ZX2C4 Instant Messenger
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zx2c4 wrote: What is the best way to calculate the current speed of the download?
Since the event is conveniently raised after every 1KB is downloaded, I believe this is simply the 1/(ti - ti - 1) where "t" is the wall clock time.
/ravi
My new year's resolution: 2048 x 1536
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com
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Right. That's what I'm doing. But how do I make it not the average rate, but the present rate instead?
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Oh, that's even easier! Just keep track of the total # bytes downloaded and the total elapsed time and divide the 2. 
[edit]
Wait, my previous post gives you the present download rate. If you want the average download rate, see the current post.
[/edit]
/ravi
My new year's resolution: 2048 x 1536
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com
-- modified at 18:54 Wednesday 3rd May, 2006
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Nono you miss read -- that does the average rate. I want the present rate.
Doing 1/(difference between time now and time of last event) will produce sporatic behavior -- the number jumps around tons and tells nothign to the user.
Is the only way to do this to just do 1*n / (difference between now and time of n events ago) ?
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zx2c4 wrote: Doing 1/(difference between time now and time of last event) will produce sporatic behavior
Yes, it will if the download rate isn't constant. The average rate (average of all "present" rates) is nothing but the total # bytes downloaded divided by the time taken to download them.
[edit]
You could take Guffa's approach and calculate the average of the last "n" chunks.
[/edit]
/ravi
My new year's resolution: 2048 x 1536
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com
-- modified at 19:03 Wednesday 3rd May, 2006
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I've tried it and the behavior is sporatic -- the time interval is too small.
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Keep the time for the last few blocks, and calculate the average speed for them. That way you get a more accurate speed than just calculating the speed of the last block.
---
b { font-weight: normal; }
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Is there any other way than grouping a block of events together?
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What do you mean?
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b { font-weight: normal; }
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well yes there is, but you said you didn't like it when you didn't group because the time frame was to0 small the the results were too erratic
You only have three choices here:
1) display the total average transfer rate (which u already do).
2) display the rate at which the last 1k block came in (which you don't like)
3) group up 2, or 3, or 4 or 5 1k blocks and display a moving average
Those are your choices...pick one.
FWIW, you can do a fairly clean moving average by creating a variable for the total time it's taken for the last n number of blocks. Every time a new block comes in, figure out how much time went by, subtract the old average rate (sumx/n) then add the new amount of time and then display to the user the new sumx/n value.
Note that the first time you subtract sumx will still be 0, so subtracting sumx -= sumx/n will still equal 0; This has the effect of the "download speed" starting out kind of slow then picking up until you reach n blocks, then it will be displaying the average of the last n blocks from there on out. You also don't really have to "group" anything or re-organize your downloads, just add one variable and do a little math.
I've used that method for years to display moving averages and all kinds of other statistics (add a sumx^2 and a different equation to get standard deviations), about the only thing you have to watch out for is that your sumx doesn't overflow, but with todays 32bit integers and the numbers you're talking about that won't likely be an issue. It beats the heck out of having to allocate arrays or remember each individual download timeslice. Just one variable and a little math.
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This is exactly the sort of solution I'm looking for. However, I still do not understand completely the math involved. Can you write some psudo-code to help demonstrate this idea?
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well now, I'm not going to do the whole thing for you.
I don't know how you have it set up so it's a bit tough for me to guess. but assuming you have a function that gets called every time a 1k chunk is downloaded I'd do it this way:
Forgive the lack of indenting, I never have figured out how to put tabs in these messages, I hit the tab key and my cursor jumps to the next block in the web page. I used spaces, but they don't make it either.
<br />
startdownload()<br />
{<br />
m_sumx = 0;
m_numsamps = 3;
}<br />
new1kblock()
{<br />
int elapsedtime = whateveryouuse();
<br />
m_sumx -= m_sumx/m_numsamps;<br />
m_sumx += elapsedtime;<br />
float dlspeed=0;<br />
if(m_sumx>0)
dlspeed = 1024.0/(float)m_sumx/(float)m_numsamps;<br />
<br />
}<br />
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Thank you so much!
The download speed seems much more sporatic though :'(.
Here's my implementation:
public void UpdateStatus(double percentage)<br />
{<br />
this.progressBar1.Value = (int)Math.Round(((double)this.progressBar1.Maximum * percentage));<br />
this.label2.Text = String.Format("Progress: {0}%", Math.Round(percentage * 100.0, 2));<br />
_movingAverage -= _movingAverage / (double)SAMPLESIZE;<br />
_movingAverage += (DateTime.Now - _lastSegment).TotalSeconds;<br />
_lastSegment = DateTime.Now;<br />
if (_movingAverage > 0)<br />
{<br />
this.label1.Text = String.Format("Speed: {0} kb/s", Math.Round(((double)SAMPLESIZE * (double)StreamUtils.FilePacketSize / 1024.0) / _movingAverage, 2));<br />
}<br />
else<br />
{<br />
this.label1.Text = "Speed: N/A";<br />
}<br />
}
The download speed is strangly sporatic though...
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maybe things are happening faster than you think. Put a temporary label1.Text = String.Format("_movingAverage={0}", _movingAverage)
statement to see what kind of values you are working with.
ie.
is it typically 0, 0, 3, 0, 3, 0, 3?
or is it typically 35, 39, 31, 39...?
What about adjust the SAMPLESIZE up, that have any effect?
Tinker a little and use the debugger you'll get it 
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I'm looking at programitically making a scanned pdf full text searchable. Does anyone know how to do this. You will be my hero!
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Hi all,
I'd love to benefit from some of the expert advice which I regularly see on this site...
I'm creating a new application which will include high-end video playback with live compositing of graphics and possibly even 3D elements. It can be a bespoke system and therefore can be reliant on high-end graphics cards and specific software configurations. It could be targeted specifically at Windows XP or Vista.
My current experience includes most graphics/multimedia apps plus the following dev environments:
- C++
- MFC
- C#
- .Net
- Managed DirectX (currently learning)
For playback I am currently looking at DirectX as the primary technology. Does anyone have any advice or specific resources for the following:
- OpenGL v. DirectX for 2D rather than 3D
- 2D uses of DirectX (Directshow's future seems vague)
- General advice
Many thanks in advance guys,
Simon Reveley
Guildford,
UK
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I have a program for processing certain log files with a .log extension. The program is working fine and I've associated the .log files with it (by right clicking, selecting open with, etc) and double clicking the .log file spawns the program and inserts the file just like I want. However if I click on another it spawns a new instance of the program. I'd like it to re-use the current instance and I have been unable to find a way. I'm using Visual Studio 2005 C# Express Edition. Any help would be greatly appreciated.
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There are some articles here on Codeproject which cover this topic. Simply search for "single instance".
www.troschuetz.de
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I've found several that talk about how to ensure you're running a single instance. But I haven't been able to work any of those into loading the new file. :/
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You may be able to do something like this:
<br />
void Main(string[] arguments)<br />
{<br />
if (IsFirstInstance())<br />
{<br />
StartAndSubscribeToStartEvents(arguments);<br />
}<br />
else<br />
{<br />
PublishStartEvent(arguments);<br />
}<br />
}<br />
The IsFirstInstance() method would use one of the mechanisms floating around for determining whether an instance of the application is the only instance running. The StartAndSubscribeToOpenEvents() would, obviously, start the application as normal. It would also create a subscription to some kind of event that will be published whenever a subsequent instance of the application is started. The event could take the form of a MSMQ message, a method call using .NET remoting, windows messages, shared memory, raw sockets--whatever your favorite IPC mechanism may be. The PublishStartEvents() method would be invoked whenver a subsequent instance of the application is started. It publishes the start event, passing any arguments the instance may be given (e.g. the path to the log file). The primary instance then gets notified of the event and can do whatever it likes with the event data (e.g. open the log itself).
Just an idea.
-Phil
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Hi all!
I have DataGridView whose sourse I set to a datatable with 4 columns
containing data. I then remove a column, create a DataGridViewComboBoxColumn and insert this into the same location as the column that was removed. I want to set as the selected value in the combo box of every cell in the DataGridView a specific value I have stored in the column of the datable that I removed in the DataGridView.
How can I set a value in a cell of the DataGridView that contains a DataGridViewComboBoxColumn?
Thanks for your help,
~~Elvia
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I tried dataGridView1.Rows["RowName"].Cells["ColumnName"].Value = "1"; but it doesn’t work.
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hi there
first use findcontrol function for getting the control combobox then set its value.
(controltype)dataGridView1.Rows["RowName"].Cells["ColumnName"].findcontrol("ControlID").value = "1"
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