Using A Regular System.Windows.Forms.Timer?
Jan 11, 2010
Hello,
I'm writing a windows service and initially tried just using a regular System.Windows.Forms.Timer, but never saw it's tick event get fired in my debugger. From doing some research, it appeared that I needed to use the S ystem.Timers.Timer control instead. In order to make debugging easy, I set my timer interval to a really short value 1000 ms. I'm seeing some rather strange behavior, though. It appears that my timer control is creating multiple threads within my application, or is this just a bug in my debugger? I have an event handler for the Elapsed event like so:
[code]...
When I step through my code like this, it now appears to work as expected. Has anyone else run into this?
View 14 Replies
ADVERTISEMENT
Jun 15, 2009
I'm wondering what exactly is the difference System.Timers.Timer and System.Windows.Forms.Timer???
View 4 Replies
Feb 4, 2012
I have a System.Windows.Forms.Timer named "DialogBoxTimer" set up on a form. When the form loads, it has a command to stop the timer. I have a routine [SPDataRecd(...)] that handles SerialPort1.DataReceived from a serial port (modem). When it is activated by a modem event, I want it to start the timer [DialogBoxTimer.Start()], but it doesn't work.If the timer is running, SPDataRecd can *stop* the timer [DialogBoxTimer.Stop()], but it can't start a stopped timer.
View 6 Replies
Dec 28, 2010
Imagine that I have a System.Windows.Forms.Timer with 1000 ms interval. If I call Timer.Start() method and after 500 ms I call again Timer.Start() what happens? The second Start call will reset the interval or not? Are there any side effects?
View 3 Replies
Jan 15, 2009
I need an accurate timer to interface a Windows application to a piece of lab equipment.I used System.Timers.Timer() to create a timer that ticks every 10 msec, but this clock runs slow. For example 1000 ticks with an interval of 10 msec should take 10 wall-clock seconds, but it actually takes more like 20 wall-clock sec (on my PC). I am guessing this is because System.Timers.Timer() is an interval timer that is reset every time it elapses. Since it will always take some time between when the timer elapses and when it is reset (to another 10msec) the clock will run slow. This probably fine if the interval is large (seconds or minutes) but unacceptable for very short intervals.Is there a function on Windows that will trigger a procedure every time the system clock crosses a 10 msec (or whatever) boundary?
UPDATE: System.Timers.Timer() is extremely inaccurate for small intervals.I wrote a simple program that counted 10 seconds several ways:
Interval=1, Count=10000, Run time = 160 sec, msec per interval=16
Interval=10, Count=1000, Run time = 16 sec, msec per interval=15
Interval=100, Count=100, Run time = 11 sec, msec per interval=110
Interval=1000, Count=10, Run time = 10 sec, msec per interval=1000
It seems like System.Timers.Timer() cannot tick faster that about 15 msec, regardless of the interval setting.Note that none of these tests seemed to use any measurable CPU time, so the limit is not the CPU, just a .net limitation (bug?)For now I think I can live with an inaccurate timer that triggers a routine every 15 msec or so and the routine gets an accurate system time. Kinda strange, but...I also found a shareware product ZylTimer.NET that claims to be a much more accurate .net timer (resolution of 1-2 msec). This may be what I need. If there is one product there are likely others.
View 5 Replies
Sep 8, 2010
I have the code which checks if there is a selected tab
Private Function GetBrowser() As WebBrowser
If TabControl1.SelectedTab IsNot Nothing Then
For Each c As Control In TabControl1.SelectedTab.Controls
If TypeOf (c) Is WebBrowser Then
Return c
[Code]...
View 2 Replies
Mar 16, 2009
With the following imported namespaces in my project :
Imports System.Windows.Forms
Imports System.Reflection
.. I cannot add..
[code].....
View 6 Replies
Apr 28, 2009
I have a panel with some controls in it (several textboxes, a slider, 2 buttons, and a small groupbox).. When I click a button, I want all of the textboxes within the panel to be readonly... So I have this code: [code] When I run it though, I get the following error:Unable to cast object of type 'System.Windows.Forms.Button' to type 'System.Windows.Forms.TextBox'.If I remove a button, it moves on to give me the same error but for a label..
View 4 Replies
Apr 14, 2011
An unhandled exception of type 'System.StackOverflowException' occurred in System.Windows.Forms.dll it also says make sure you do not have infinate loop or infinate recursion il give all code in order that they are executed in Check the chechbox and it disables all irelevent stuff and populates the combobox
Private Sub CheckBox_Spray_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox_Spray.CheckedChanged
If Me.CheckBox_Spray.Checked = True Then
[code]....
View 4 Replies
Jul 11, 2010
i have a need for my vb.net app to perform methods at regular intervals. it needs to check sql tables and react to data found, send email and sms messages. i've tried using a loop but this only allows me to perform 1 check ie checking sql tables. the app needs to execute a method every x minutes. i tried using system threading but i got errors.
View 1 Replies
Mar 12, 2010
When I do this
Public Class cInherits : Inherits Panel
I get this: Base class 'System.Windows.Forms.Panel' specified for class 'MenuButton' cannot be different from the base class 'System.Windows.Forms.UserControl' of one of its other partial types.
How do I inherit?
View 4 Replies
Jun 12, 2011
i need to get data from checkbox in a groupbox. in the groupbox, it also have a label. so my coding as below
[Code]...
View 1 Replies
Jun 30, 2011
Whatever project I'm making, I always encounter a problem with a Windows Forms Timer control, I guess I just make a little mistake somewhere... So I thought I'd post it here and hopefully someone here can explain what I'm doing wrong.
[Code]....
View 3 Replies
Oct 29, 2011
I am trying to use values from form1 in my project, in form2, but Im not sure how to do it. I've tried
txtboxTotal = (Form1.vsbLength * Form1.vsbWidth) * Pattern
But I get: operator '*' is not defined for types 'System.Windows.Forms.VscrollBar' and 'Systems.Windows.Forms.VscrollBar.'
View 14 Replies
Jan 23, 2010
Private Sub wb_Scrape(ByVal sender As System.Object, ByVal e As
[Code]...
View 5 Replies
Oct 20, 2010
Win7 64 bit; fully patched VS2008 targeting FW2.0; VB.Net; running in Debug Mode (not tested in Release mode)I have a resonably complex app which I am refactoring a bit. As part of that, I relocated some code from a subroutine into a Click Event Handler. The Event Handler will, late in the handler, call the, reduced in function, subroutine. The point of this is thatNow when I click the button associated with the modified Handler I get:A first chance exception of type 'System.AccessViolationException' occurred in System.Windows.Forms.dll<br />With Error System.AccessViolationException Attempted to read or write protected memory.This is often an indication that other memory is corrupt.
at MusicManager2009.frmMain2.cmdLoadAlbum_Click(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
[code].....
All functions of the app, except those that start from the buttonclick in question, work as before in the problem version.The problem persists after rebuilding the entire solution, after restarting VS, and after rebooting the PC.
View 10 Replies
Feb 19, 2010
When I run my project I get "An unhandled exception of type 'System.StackOverflowException' occurred in System.Windows.Forms.dll"
Public Class frmViewReport
Dim objForm As New frmViewReport
Private Sub frmViewReport_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
objForm.ViewReport("C:a2.rtp", , "@parameter1=test�mter2=10")
[code]....
View 1 Replies
Nov 16, 2009
I have the following code running, the first time I change the selected index, everything runs smoothly. However, if I try to change the selected index again, nothing happens and the subcategories combobox values do not change.
Private Sub cboMainCategory_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cboMainCategory.SelectedIndexChanged
'* make sure the combobox is fully loaded
[code]....
View 2 Replies
May 6, 2009
I keep getting an eroor this error says: An unhandled exception of type 'System.ArgumentOutOfRangeException' occurred in system.windows.forms.dll Additional information: Specified argument was out of the range of valid values.
Option Strict On
Public Class frmWeeklyReport
Inherits System.Windows.Forms.Form
[code].....
View 7 Replies
Feb 12, 2011
A first chance exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll It displays in my Immediate Window when i run my program, I'm using a text reader to read a number of XML files using background worker...most the time it stops so something is wrong but sometimes it works fine.
View 2 Replies
Feb 6, 2010
I am working on a card game, and i get this werid error:
A first chance exception of type 'System.Reflection.TargetParameterCountException' occurred in System.Windows.Forms.dll
The code that is cousing this error is:
Private Delegate Sub ShowcardDelegate(ByVal test As String, ByVal objtest As Object, ByVal value As Boolean)
Private Sub Showcard(ByVal test As String, ByVal objtest As Object, ByVal value As Boolean)
If objtest.InvokeRequired Then
[code].....
View 10 Replies
Feb 23, 2009
I want to cast a system.string to system.windows.forms.form
View 2 Replies
Mar 31, 2010
I am writing a program for my A-level coursework But for some reason I got this build error this has never occurred to me before, I have no idea why I can't use string for the name of my form.
View 8 Replies
Mar 5, 2012
When I add a new, empty form to my VB.NET VS9 project, the linenherits System.Windows.Forms.Formis missing.What am I doing wrong here?I thought it would be added automatically.I experienced that some thing get weird if this line is not there (Form_Load is not firing, I think).
View 3 Replies
Jun 27, 2011
VB 2008, DataGridView,DataGridView1_CellLeave(sender, New System.EventArgs)
"Unable to cast object of type 'System.EventArgs' to type 'System.Windows.Forms.DataGridViewCellEventArgs'."
What is the Correct String for "New System.EventsArgs"
Anybody there is to help me out.
View 1 Replies
Jan 17, 2011
[Code]...
there is one problem here the root node on the line "GetDirectories(info.GetDirectories(0, rootNode))" here is the error "Error 1 Value of type 'System.Windows.Forms.TreeNode' cannot be converted to 'System.IO.SearchOption'."
View 4 Replies
Jun 25, 2010
My project worked a first and now its giving me a problem.The error
Quote:
Unable to cast object of type 'System.Windows.Forms.MouseEventArgs' to type 'System.ComponentModel.RunWorkerCompletedEventArgs'.
View 2 Replies
May 16, 2011
[URL]The issue is as soon as I change the value of the text boxes it gives me an error and forces me to close the project.
The error is:Unable to cast object of type 'System.EventArgs' to type 'System.Windows.Forms.KeyPressEventArgs'.
However I'm supposed to clear the number of gallons used and the total charged when a change is made to the contents of the 2 text boxes on the form.
View 3 Replies
Jun 12, 2011
Unable to cast object of type 'System.String' to type 'System.Windows.Forms.TextBox'.
View 12 Replies
Apr 6, 2009
I'm trying to implement a website screen shot class as described hereThe class imports the following methods
Imports System
Imports System.Drawing
Imports System.Drawing.Imaging
[code]....
View 3 Replies
