Reducing redraw flickering on vb.net web application - vb.net

I have a page on my web application which has a chart that gets retrieved using a timer. Is there a way to avoid the flickering everytime the chart is redrawn?
Since It's a web application, I guess the doublebuffer property isn't available, or at least I didn't find it and assumed it's webform related.
I would appreciate any help in the matter.

A quick and easy but not suggested solution is to call the redraw manually and remove the event.
So you would remove the event handler and you call the function that redraws the chart when you think is required. i.e After the resize is done or after a value is changed etc.

Since it is a web application, I guess the redraw you are talking about is made using a browser page refresh.
If so, you should take a look at Microsoft Ajax Framework, and a UpdatePanel control to just refresh the specific chart part of your page. Should be smoother then.
http://www.asp.net/ajax

Related

How to stop webbrowser control refreshing when server requests it

I have a webbrowser control that points at a webpage that holds some fields that change quickly. When these fields change the server seems to request that the webpage refreshes. This poses a problem if programatically interact with the webbroswer. Is there anyway to force the webbrowser to not refresh? No real code to show. since I'm hoping this is a one line property I can create/add.
Maybe you are looking for the WebBrowser.Stop() Method (MSDN)

CTRL+ TAB when webbrowser is in focus

I have a windows application with a tabcontrol. One of the tab of the tabcontrol has a webbrowser control.Now the issue that I am facing is when the focus is inside the webbrowser control, the normal Ctrl+Tab functionality of the tabcontrol is not working.I want the Ctrl+Tab to change the selected tab of tabcontrol even when the focus is inside webbrowser control in selected tab.How to achieve this ?
I have already tries overriding ProcessCmdKey.but it does not get hit when focus is inside webbrowser control.
I also tried registerhotkey method ,it works but it locks the Ctrl+Tab hotkey within my application & system doesn't respond to any other Ctrl+Tab presses outside my application when application is running, which is expected behaviour of registerhotkey.
Here is the code you need:
If WB.ContainsFocus Then
MsgBox("We have focus, disappearing...")
WB.Document.Body.RemoveFocus()
End If
Now, the question is, when to run that code. If you put it in the WebBrowser1_GotFocus event, you'll need to turn it on and off. Turn the code off if the user is interacting with the WB Control, and turn it back on when they are not and when you expect to be experiencing the problem you've mentioned.
Of course, you could add another line to ensure a particular control/tab/panel etc gets focus after you remove focus from the body. Also, here are 3 other SO questions that have answers which may help you, but these will take you in directions different to the direction I've provided, probably due to the fact that the questions are not identical to yours, but are similar enough to be useful (not listed in order of preference).
Prevent WebBrowser control from stealing focus?
Webbrowser steals focus
Focusing WebBrowser control in a C# application
UPDATE:
I just wanted to add, instead of the .Body.RemoveFocus() you could do this:
WB.Document.Body.Parent.RemoveFocus()
Which I prefer, since the .Document object didn't have an explicit .RemoveFocus method on the intellisense I was gettign in VS2012 RC. This is probably referring to the HTML tag (and not the .Document object) and since the html tag is the only parent to the body tag, it makes sense, and there is no "HTML" object directly available in the intellisense under object, since you can get it via other means, so it's just more convenient doing it this way.
Cheers, and let me know if you need more info on anything.

Triggering TAB key to shift control by vb.net coding

I am opening a web site in a vb.net 2008 webbrowser control. I want when I open the 3rd page of the web site then after the page is loaded , control focus programmatic-ly by Triggering TAB keypresses automatically by my code . Please tell me the solution to shift the focus control ?
I don't know if I have understood your question right, but you could try the following,
Keep track of whether you are on the third page in your web-browser control. If you are, you can execute a JavaScript function, which changes the focus of the text-fields.
Page.ClientScript.RegisteredStartUpScript(GetTypeOf(), "function_change_tabs", script, True)

How do I force a page to refresh the data upon reload after entering new record

When I create a new record by submitting an .aspx page the new record is not showing up. I have to navigate away from the page and back to it for the new data to show.
How do I refresh the data up reload??
i think you need to call databind() on your grid. If that's an unlucky guess, we're going to need more context - can you please post your code (aspx and vb)
try Application.doEvents() right after you update the object in your code.
It's a shot in the dark really since we really don't know what you're code is doing, but if I ever have problems with something updating in VB.net, 9 times out of 10 calling that method fixes it.
You will need to call DataBind() on whatever object your using for your data connection, and then you will have to refresh the page unless your using AJAXified controls inside of an UpdatePanel that has a trigger set to your submit button. But without a code listing, knowing how your talking to the database, or anything of that sort, its really hard to give any code that will help.

Controls disappearing on timer event-vb.net

We have a question regarding VB.Net 2008.
We are used control array in vb.net and third party timer controls.
When handle received from external application to timer control event procedure,
after this form becomes blank and controls disappear.
What we have to do to persist the controls.
You asked what you have to do to persist the controls. It's not clear whether you mean winforms or webforms, but I can answer for both possibilities:
If it's the former, you have it backwards. The default behavior of all controls is that they are "persisted" until you tell them otherwise. If anything disappears, it's because you have code somewhere that tells it to. That's where you need to start looking.
If it's webforms/ASP.Net, the problem is that you don't understand the page lifecycle. Everything that raises server events, including your third party timer controls, causes a post back. That's how events work - the browser posts the form back to the same url in such a way that the server knows to call a your event code at the right time. The thing here is that as far your server is concerned, it's still just a new http request, and that means you're working with a brand new instance of your page class every time this happens. If you've previously added some controls to your page, it doesn't matter. That was an old instance that was discarded and probably disposed by the time the page was visible in the user's browser. If you want to keep those controls, you need to make sure you add them to the page on every postback.