Hooking In To Application.DoEvents Method
Jul 25, 2009
I am not very familiar with VB.NET so I don't know if this is possible.Some code I am working on is setting the properties of a very large class. In the setter of each property an event is raised to indicate that the class data has changed. An event handler then serializes the instance of the class to a database.Obviously I do not want this to happen after each property is set, so I need to either have a delay before saving, or something else.I am keeping a large list of instances in a cache implementation already, so one option would be to only process the cache every now and then and save all unsaved instances in cache to the database.So I tried to see if I could derive a class from Application (and override DoEvents), but it is NotInheritable, so no luck there.
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Aug 2, 2011
I have a windows forms application written in VB.NET which scrapes information from serveral web pages (who doesn't right)? Anyway, I am having problem with one particular site where partway through the page navigation my application hangs. When I press pause (or break) in the debugger, it stops on a call to System.Windows.Forms.Application.DoEvents.
Resuming execution shows that it really is stuck on this line (it does not reach the next line of code). It also hangs about the same point each time I run it (at least its consistent). Since System.Windows.Forms.Application.DoEvents yields to other threads on the same processor and then resumes execution of the current thread, I think the problem is that some other thread is not behaving well (not returning from some event handling code). I thought Windows 7 was pre-emptive, which makes me
doubt that theory but I really don't know.
[Code]...
The program scrapes somewhere between 12 and 14 pages before it gets stuck on the call to DoEvents. Does anyone have a clue why this would happen? Why would any call to DoEvents hang?
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Jul 18, 2011
i made an application for serial communication. for this application i need to set delay time. during this delay time i m doing some other task. So for those task i need to take back control from delay function, for this purpose i am unsing Doevents() function.Its work fine On other OS (XP, Windows7 32/64-bit). But Application.DoEvents() function halt and crash in windows vista.
Private Sub TimeDelay(ByVal DT As Integer)
Dim StartTick As Integer
StartTick = Environment.TickCount()
[Code].....
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Sep 12, 2011
I'm trying to hook the keyboard to make some action when I'm running a DirectX application. I want to press some keys like "F2" or "pagedown" when I'm running dx app and see msgbox appears. Can anyone show me the code?
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Jun 6, 2011
Any good alternative to using DoEvents in VB.NET
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Dec 22, 2010
I am re-posing this question because the prior post has gotten really full of side issues so I fear the main problems has been lost.I have a windows forms application written in VB.NET which scrapes information from serveral web pages? I am having problem with one particular site where partway through the page navigation my application hangs. When I press pause (or break) in the debugger, it stops on a call to System.Windows.Forms.Application.DoEvents.
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Dec 15, 2009
how to exit out of the Application.Do() as i am hanging in that .Here is a sample of my code.
Imports PDFCreator
Imports System.Windows.Forms
Public Class Form1
[Code]....
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Mar 8, 2009
My mdi VB.Net application performs a long operation on some data. Ideally I should use a separate thread to prevent the dreaded "Not Responding" message.My problem is if I use a separate thread users then have the ability to click on other controls in the application which can directly affect the operation my background thread is working on, creating an error.
Is there any way to prevent all the mdi windows, toolbars and other controls from receiving mouse clicks and keyboard input during my background thread's operation?
Or is there a way to clear the message que before performing a Application.DoEvents?
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Dec 11, 2009
I have a unique situation in that I've developed a VB.NET application for AutoCAD. The way this works, you build your project into a dll and utilize AutoCAD API references when designing the project. From AutoCAD, a "Netload" command will load your dll into it's namespace to run. AutoCAD then essentially takes ownership of your application from here on out. The application is ran using a command defined in a method's attribute:
<CommandMethod("CommandNameForApp")>Public Sub MyCommand()
'Code Here
End Sub
Due to the heavy load of processing loops as it evaluates AutoCAD drawing data, processes this data, and generates many, many Excel reports, I've added a boolean property called Cancelled to my Progress class. When the user cancel's the process, this is seen by the process and further evaluation is ended and everything is cleaned up nicely. In order for this to work though, I have to implement Application.DoEvents. Without it, the Cancel feature will not work at all. With it, now instead of allowing the application to stay loaded, the Command method is fully closed.I have added a go-to point and simply verify that the application isn't closing because of a user-cancellation event. Here's what it looks like now:
<CommandMethod("WireShop")> Public Sub WireShopApplication()
'Initialize Configuration File Data
'Initializes ValidBlocks, MarginDistance, WindowDistance, and HelpFileName Properties
If ConfigurationFileInitialization() = False Then Exit Sub
[code].....
In my opinion, this seems a little hokey. However, I'm not that familiar with exactly what Application.DoEvents is doing in the background to understand how to "head it off at the pass".
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Nov 9, 2009
I'm trying to automate the process of logging into twitterfeed.com, and filling in the information (the feed url and twitter username are pulled from textboxes). I had it mostly working the other day, even if it is a bit sloppy (the only way I could get one button to click is to send 50-some tabs). However, lately it seems to enter in a sort of loop. When I pause the program, Visual Studio indicates that it is the Application.DoEvents in the Private Sub "wait" that is still running even after it should be.
Public Class Form1
Private feed, username, temp As String
' Code stolen off of a website as an alternative to sleeping, or trying to do a timer + while combo like I had been doing
[Code].....
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Mar 4, 2010
I'm running in to a problem that I was able to fix with Application.DoEvents, but don't want to leave that in because it might introduce all sorts of nasty problems. Background: Our app is primarily a desktop app that makes many calls to a web service. We control everything but changes to the overall system design are not going to be seriously considered. One of those calls, Calculate, is used very often, and occasionally can take a few minutes to process all the data to return valid results.
[Code]...
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Mar 15, 2009
We just spent 300 man-hours fixing a buggy application in the field. It all came down to calling Application.DoEvents (re-entrancy problem).This was not caught in design reviews, code reviews.The code was inserted two years ago with the first version; the application was always "flaky" but recent changes exposed the re-entrancy problems to a greater degree. This incident is the second time in our organization that Application.DoEvents caused failures and multi-man hours of debugging.It was discovered in this case by simply noticing the call,buried way down in a complex event handler for an asynchronous task.What do you suggest to prevent this issue from happening again:
Add checkin gates to source control?
Developer training?
Code Analysis rules (why is this not already a built-in rule?)
How to I enforce a coding practice?
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Mar 28, 2012
I am indifferent if you are a VB.NET or C# or other .NET developer. I have a FACTORY class like the following:
[Code]...
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Mar 17, 2012
i want to which way is better when concentration is on processing speed. i want to call a method that compute some data that method is on another form in my windows form application then what you prefer is better way 1) to call that method in another form and use returned value or create similar method in form where it is required.i want to make it's processing fast.
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Aug 1, 2010
I want to know how to hook a tcp connection of another program and listen them. I dont need to manipulate the packets though.I just want to record for example chat messages.
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Sep 9, 2009
I'm working on a tool that requires overlays ala X-Fire. I'm hoping to do it in C# or VB.NET rather than resorting to C++, but the only solutions i've found for .NET cause a large performance hit (~20FPS in games). Take a look here: [URL]
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Feb 16, 2010
I have been working on a project for some time now and I am stuck. I am trying to sense when a navigation software speaks so i can mute the volume of everything else on the computer.
my problem is that i cant properly sense the audio of the software. i am using windows 7 and vb.net. i have done a good amount of research, but i have not come up with an answer.
i am almost positive that i need to intercept the win32api call of the software to trigger the mute that i will use. i dont know how to do this, all the information i can find that is even close to this subject is for 98, nt and 2k.
does anyone know of any books (or websites) that contain information on this subject?
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Feb 27, 2010
I'm using Process.Start method to launch another application from my application. Until today, there was no problem. But I have tested my application in a different OS, Windows XP (SP3), and my application didn't work right on that. I'm also using arguments to run that application. I guess for some reason my application couldn't send arguments to other application correctly under Windows XP. Maybe it is related to my code. But you should know, it works great on Windows 7.
[Code]...
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Jun 18, 2011
How can I disable Alt-F4 and Ctrl-Alt-Del?Can I lock all combinations of a key with the Alt key? I got a sample from the internet, it only can disable Alt+Tab, Alt+Esc, Ctrl+Esc, Windows Key
Select Case wParam
Case 256, 257, 260, 261
'Alt+Tab, Alt+Esc, Ctrl+Esc, Windows Key
blnEat = ((lParam.vkCode = 9) AndAlso (lParam.flags = 32)) Or _
[code]....
Where can I see the button code list in lParam.vkCode = ?How can I make it able to disable Alt-F4 and Ctrl-Alt-Del or disable all combinations of a key with the Alt key?
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Oct 7, 2008
Is there a way in vb.net to subclass/hooking in to any controls scroll bar and change it is colours etc (I saw this once in C++ but lost it). It�s ok for MS giving us user owner drawn controls, or at the very least allowing us to draw the controls information but it looks dam write awful if the scroll bar does not fit into the GUI.
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Aug 17, 2011
I play a midi file using this simple win32 api call:
MidiMsg = "open " & c_midiFile & " type sequencer alias mid1 notify"
ret = mciSendString(MidiMsg, "", 0, Form1.Handle)
MidiMsg = "play mid1"
ret = mciSendString("play mid1", "", 0, Form1.Handle)
Callback message MM_MCINOTIFY has a value of &H3B9 (found it using "spy++")I have to know when this message (MM_MCINOTIFY) is fired and read his parameters. In an old version of code I've written years ago in VB6 i had to use CallWindowProc and SetWindowLong win32 api, but now in VS2005 i cannot get it to work.Still I have to try with unmanaged code or are there any other ways to do this in vb .net?
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May 13, 2009
i found an example for hooking global mouseclicks, but i can't get it running.the error is in the start subroutine, -SetWindowsHookEx failed.what am i doing wrong?
Imports System.Runtime.InteropServices
Public Class UserActivityHook
Public Delegate Function HookProc(ByVal nCode As Integer, ByVal wParam As Integer, ByVal lParam As IntPtr) As Integer
Public OnMouseActivity As MouseEventHandler[code]....
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Aug 23, 2010
I have been working in an Migration Application where i find out some weird problem , Leave Event Fires twice causing validation to fire twice , hence i want to intercept the events to be processed by application..Hence require help in hooking the delegates so that i can get a list of the events that are to be processed .If anybody can help me out by giving some info or code as how to implement hooking in a textbox leave event/
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Jun 1, 2009
Has anyone ever come across a way of a way to create an app that kind of mimics what Terminal Services manager does in Windows2003/XP.
I would like to write something that would either go and query a farm of server every n secs a get me a list of users logged in, there process's etc or do maybe type a username in and it goes and finds the user in the farm and returns their details.
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Nov 2, 2011
I currently have software that sends out plain text(i.e. 'X') to comm 1 port and was wondering if there was any way to capture that plain text and also respond to that port on the same compute as the port without having anything plugged into the machine (i.e. 9 pin serial cable). I am trying to avoid buy any more hardware as this is an objective to acutally cut down on hardware.
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Aug 12, 2009
I have two applications Application 1:source
Public
Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Button1.Enabled =
[Code]...
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Dec 19, 2008
Basically, I have an app that communicates with a server. I need a way to monitor all the sent and received packets that are being transmitted through the app. I've been killing myself the past two days trying to figure a way to hook into ws2_32.dll to monitor these packets but I can't find a way!
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May 23, 2005
I am using ASP.NET and was wondering what i can use in replace of the DoEvents() in vb6?
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May 4, 2009
What's the equivalent of the VB6's DoEvents in .NET?
EDIT:I have a Sub that takes a long time to do its work. (it has a do-while) when I call it, The form turns white. in VB6 I used to put a DoEvents in the method (inside its do-while) to prevent this.
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Jul 27, 2011
I tried to use this code in the form:
AddHandler MyControl.MouseDown, AddressOf StartDrag
This wont give me an error, but it doesn't happen anything when I mouse down on the Control.
the same doesn't work if I put it in the user control.
Private Sub StartDrag(ByVal sender As Object, ByVal e As MouseEventArgs)
Dim Box = CType(sender, Control)
Box.Tag = New DragInfo(Form.MousePosition, Box.Location)
End Sub
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