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Apologies for the shouting but this is important.
When answering a question please:
- Read the question carefully
- Understand that English isn't everyone's first language so be lenient of bad spelling and grammar
- If a question is poorly phrased then either ask for clarification, ignore it, or mark it down. Insults are not welcome
- If the question is inappropriate then click the 'vote to remove message' button
Insults, slap-downs and sarcasm aren't welcome. Let's work to help developers, not make them feel stupid.
cheers,
Chris Maunder
The Code Project Co-founder
Microsoft C++ MVP
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For those new to message boards please try to follow a few simple rules when posting your question.- Choose the correct forum for your message. Posting a VB.NET question in the C++ forum will end in tears.
- Be specific! Don't ask "can someone send me the code to create an application that does 'X'. Pinpoint exactly what it is you need help with.
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cheers,
Chris Maunder
The Code Project Co-founder
Microsoft C++ MVP
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Hey guys I'm doing Computer Science(hons) with Catholic University nd i'm now in fourth year.I'm doing a VB.Net project of development a fast and robust Internet Browser.I've developed part of the program but will need to see another one with the code for me to make modifications and refinements to the one I got..
topodzie
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A good step would be to start contributing to the Firefox[^] development.
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So what are you asking?
BTW: I didn't attend a Catholic University but did learn how to spell and use proper grammar and punctuation.
topodzie wrote: VB.Net project of development a fast and robust
That's the best oxymoron I've heard in a while. 
Failure is not an option; it's the default selection.
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sorry sir but english is not my fist language,I'm rily sorry  :(
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Do a search on the internet. You should be able to find something.
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Well, you could always down the XulRunner or Webkit sources and have a look at those. Mind you, they aren't running on top of the .NET framework - as much as I love coding with it, I wouldn't choose it to create a web browser with.
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topodzie wrote: Hey guys I'm doing Computer Science(hons) with Catholic University nd i'm now in fourth year
Gratz on surviving that far.
topodzie wrote: I'm doing a VB.Net project of development a fast and robust Internet Browser.I've developed part of the program but will need to see another one with the code for me to make modifications and refinements to the one I got..
Did you create a browser (something that parses the html before displaying it) or did you re-use the browser-control, effectively writing a new UI?
Bastard Programmer from Hell 
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I started with a new User Interface
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..and you're looking for similar projects, like this one[^]?
Bastard Programmer from Hell
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I am using a DataGridView control to display very wide tables; number of columns approx 1,000. When the table get wide an error is generated when assigning the .datasource on the DataGridView. The error is the following: "Sum of the columns' FillWeight values cannot exceed 65535."
I have done a little research and it appears that MS never designed DataGridView to show tables that are very wide. They recommend < 300 columns and I saw somewhere that you could adjust some of the parameters on the columns to increase that number up to 655. I need more than that and would prefer to not implement a "paging" solution.
Can anyone help with a proposed solution? How does Excel display very wide tables of data?
I'm using .net 4.0 and vb.net but a C# solution would be fine.
Thanks in advance !
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I suspect some of the DGV internals is still working with 16-bit quantities, maybe all the coordinates are short.
I'm not very optimistic you'll get it to work, however I would try and dumb it down, e.g. by disabling the autoformatting (set DataGridViewAutoSizeColumnsMode.None and give each column a fixed width before providing the data).
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By the way, also Excel is very limited in the number of columns (255? 512?), though the number of rows can be a few thousand (65535?).
Can you locate the position of the problem more closely: is it the mere number of columns which causes the problem, or the width of all the columns together? In the latter case, you could implement a workaround by temporarily setting a very small column width for the columns out of view.
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Thanks, I will look for that (is it # rows or size of displayed data). What I am doing is detecting when the # Cols is > 255 and then not attaching the DataSource. Essentially, if there is going to be a problem I disable viewing of the data; at least the program can continue to run.
Setting a very small column width for those out of view might work if it is the size of the data and not the #columns. Although, if the # cols is > 1,000 I believe there still might be a problem.
I was really looking for some kind of work around. Like a different data structure. Or maybe something derived from DataGrid or DataGridView which disables are lot of the fancy feature and just displays rows & cols.
Thanks for the answer though.
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TPIRick wrote: How does Excel display very wide tables of data?
Excel uses a custom written rendering engine. Since you seem to want to show a huge number of columns to the user (as a user I wouldn't want to scroll through it!) you have exceeded the design goals of the DataGridView. You would have to either find a grid control that supports your requirements (not likely) or create your own custom drawn data grid (not easy).
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TPIRick wrote:
Can anyone help with a proposed solution? How does Excel display very wide tables of data?
Have you ever had to find something in Excel when it's crammed with that amount of data? Once the user needs to scroll, he can also use a button to browse the next page.
You could virtualize the entire thing, drawing a grid and scrolling it's data - not the grid itself.
Bastard Programmer from Hell
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TPIRick wrote: Can anyone help with a proposed solution?
No one looks at that much data. Either they are looking for something in it or they want to manipulate it to do something else. First one means you ask the user what they want and only give them that. Second solution involves allowing the user to download the raw data (then they figure out how to manipulate it) or provide a way to manipulate it before presenting it to them.
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Out of curiosity I performed a little experiment, with the following code inside the Form's Load handler (dgv is a DataGridView):
1 for (i=0; i<10000; i++) {
2 DataGridViewColumn col=new DataGridViewTextBoxColumn();
3 if (i==0) {
4 log("col.Width="+col.Width);
5 log("col.FillWeight="+col.FillWeight);
6 }
7 col.Name=i.ToString();
8 dgv.Columns.Add(col);
10 }
As is, it fails when i=655 with the Exception you've got, because the default FillWeight value is 100, and it somehow gets summed in an unsigned short which then overflows.
With line 8 uncommented, it runs fine. That is, if you have half an hour to spare, waiting for the DGV to get loaded with (empty) columns. After the long wait, the Form and the DGV appear, with column headers, scrollbars, and everything (except for rows and actual data, as I didn't provide any).
The conclusion can only be:
1. a DGV wasn't meant to hold that many columns;
2. your app needs another way to interact with your user.
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Hi all,
I have a scenario that is puzzling me and I'm guessing at the behavior and was wondering if anyone else knew what was happening under the skin of .Net.
I have a .Net 4.0 application on a clients' Windows Server 2008 64bit back end database is an ALPHA (not relevant).
The application is 1 form with literally hundreds of controls on it and also an image viewer. It's takes up quite a bit of screen space, and has multiple tabs (at least 8) to hold all the controls.
The puzzling scenario is this:
1. Open up a simple list
2. Select an item from the list to open up the form as described above - this takes over 1min 15secs
2. Close the form (return to list in point 1)
3. Open up the same form from the list loading the controls in exactly the same way with the same queries behind it (assuming not relevant from the logs I've looked at), and it can open in 10 seconds flat.
From the looks of the memory print in Task Manager, the memory obviously shoots up when the form is first opened, but doesn't go down too far after closing the form. On reopening the form again, the memory doesn't go up much but only takes 10 seconds to open.
I'm thinking that .Net is loading up a load of stuff (!for want of a better word!) into memory on first load of form, and subsequent forms use what has previously been loaded into memory.
If it's not this that is happening, I'm not sure what is happening, as I have been asked by our client to try and make the first load of the form as quick as each subsequent one, and not sure if this is indeed possible.
Any light shed on this would be most appreciated.
Many thanks
Julian
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My initial thought here, as you haven't said what database you are hitting, is that the database connection is being pooled. On the first invocation, the connection is being created which is a time consuming process. Further invocations are able to take the pooled database connection.
You are also correct that the .NET runtime will also grab extra memory which is not released immediately, allowing space for the application to load the form in again.
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Hi
The connection to the database is active before the form loads, and is not dropped for the duration of the application lifetime (it's a secure self contained network).
The database as stated is an Alpha database running on a VMS server. We have a windows dll interface to it.
I'm interested in your point about .Net not releasing memory. If I create a new Form each time (Form1 creating Form2 - Form2 being the Form in question), do you think that .Net will intelligently store stuff it needs and call on it again when I create a new Form2?
Thanks for your response
Julian
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Assuming your description of the situation is somewhat accurate, I can only conclude one did a few things wrongly in the implementation. Adding some simple logging (with time stamps obviously) to the app would allow to pinpoint the major problems. And yes I expect there to be more than one. To name some candidates:
- user authorization on the network
- user authorization on the DB
- establishing the first DB connection
- building the GUI
- obtaining all the data
- stuffing the data in the GUI.
You'll need some facts before you can effectively tackle this, so start logging!
Alternatively, and maybe harder to implement and interpret, try simpler set-ups.
BTW: your app may or may not contain extra implementation features to make subsequent operations faster, think caching. The more of these you have, the more impossible it should become for the first operation to be as fast as subsequent ones.
FWIW: In Windows, dialog windows can be hidden and shown over and over, without recreating them. So even the most complex dialog could be shown again in a fraction of a second (and anyone can come up with ways to make things slower).
PS: if you have tab pages on a Form, then there is no need to fully populate them all before showing anything to the user, as he can see only one of them at a time. The right approach would be to either load the others in a lazy way, i.e. only when needed; or in a background operation, i.e. after the essential work has finished.
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