I'm working with visual basic express 2010 to create a very simple application.
I know this is basic stuff but i need to know how to repeat the same function every X minute while the application is being left open.
This is all my code:
Public Class Form1
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
My.Computer.Network.DownloadFile(
"http://google.co.uk/images/someimage.png", "C:/Documents and Settings/All Users/Desktop/someimage.png")
End Sub
End Class
could someone please advise on this issue?
EDIT:
This is my entire code now:
Public Class Form1
Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
My.Computer.Network.DownloadFile(
"http://new.tse.ir/en/json/MarketWatch/enMarketWatch_1.xls", "C:/temp/enMarketWatch_1.xls", "", "", False, 60, True)
End Sub
End Class
in the properties panel of the timer, I set the Enabled to true and Interval to 60000.
when i run this code, I get file downloaded but 1 second later, the file gets deleted automatically and an error pops up in the visual basic saying the operation has timed out
I tried to change the directory and still happening.
any advise would be appreciated.
Add a timer to your form in the graphical designer.
Double click the timer to generate its tick event handler code in the code window.
Move the code you want to repeat into a sub
Private Sub DownloadFile()
My.Computer.Network.DownloadFile("http://google.co.uk/images/someimage.png", "C:/Documents and Settings/All Users/Desktop/someimage.png")
End Sub
Add the command below into your timer tick event handler
DownloadFile()
Change your form.load event to
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
DownloadFile()
Timer1.Interval = x ' where x is the number of minutes*60000 because there are 60000 ticks in a minute
Timer1.Enabled = True
End Sub
The reason I've put your code into a separate sub is so that it is easily reusable in both the form.load handler and the timer.tick handler without having to write it again, and if in the future you need to change, for example the file path, you only need to remember to change it once.
Also I should add that, in the form.load handler I have included the DownloadFile method because, when the timer is enabled, it won't generate a tick until the interval has elapsed. Not at the beginning when the timer is enabled.
Also - as Plutonix suggested in comments below - If it is possible that the file to be downloaded will take longer to download than the length of the timer interval you should disable the timer in the DownloadFile sub and enable it again at the end of the sub. Like so :-
Private Sub DownloadFile()
Timer1.Enabled = False
My.Computer.Network.DownloadFile("http://google.co.uk/images/someimage.png", "C:/Documents and Settings/All Users/Desktop/someimage.png")
Timer1.Enabled = True
End Sub
Related
So i have a tray icon that should behave the same way between 3 forms. I then created this code:
Private Sub TrayForm_MouseClick(sender As Object, e As MouseEventArgs) Handles NotifyIcon1.MouseClick
If e.Button = MouseButtons.Right Then
If Not Application.OpenForms().OfType(Of TrayForm).Any = 1 Then
TrayForm.ContextMenuStrip1.Show(Cursor.Position)
End If
End If
End Sub
Which is used to handle the tray icon. How can i do to share this event between the forms so i don't have to place this same code on every form?
How are event handlers working exactly? I looked online and on MSDN and it is not clear to me.
Thanks
Are you sure that you want to share the event, and not juste the code that will handle the event?
If you don't want to copy and paste your code, which you need to handle the events of more than one form, here's a way to do it:
Declare the sub which contains the code needed to handle the event as a public shared sub. Like this:
Public Shared Sub TrayForm_MouseClick(sender As Object, e As MouseEventArgs)
So, now you have a Sub which can handle the event you want to handle from all three forms.
Now, when you initialize those forms, add a line to make the shared Sub handle the event you want it to handle:
AddHandler NotifyIcon1.MouseClick, AddressOf ProjectName.FileName.TrayForm_MouseClick
ProjectName.FileName is meant here to be the path to refer to the shares Sub inside the file where you put it. I usually name it like ProjectNameUtils.vb or something like that.
If you just want to avoid copy and pasting your Sub so you don't have to modify it at several places every time you change something, this could be a way to achieve that.
As Stipulated by Hans Passant:
Sub Eclass_EventHandler(sender As Object, e As MouseEventArgs) Handles Me.MouseClick
If e.Button = MouseButtons.Right Then
If Not Application.OpenForms().OfType(Of TrayForm).Any = 1 Then
Me.ContextMenuStrip1.Show(Cursor.Position)
End If
End If
End Sub
On the Trayform.VB just did the trick.
But about the shared event. i Have one that would have to be:
Private Sub FormClosingEVENT(sender As System.Object, e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
If Not FromMenu Then e.Cancel = True
Me.WindowState = FormWindowState.Minimized
'Application.Exit()
End Sub
How should i handle this?
I am currently working on a project and decided to create a user interface for it using visual studio with a windows forms application(Visual Basic).
The problem I'm facing is that the user interface doesn't respond as quickly and smoothly as I'd like it to.
Mainly, I am using pictures as buttons to make the user form look more modern.
However, when I hover my mouse over a "button" it takes a while until the "highlighted button" appears.
P1 is the picture of the "normal button" and P2 is the picture of the "highlighted button".
Here is the short code I have for now:
Public Class Main
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub PictureBox1_MouseHover(sender As Object, e As EventArgs) Handles P1.MouseHover
P1.Visible = False
P2.Visible = True
End Sub
Private Sub P2_MouseClick(sender As Object, e As MouseEventArgs) Handles P2.MouseClick
'Call cmdInit()
'Call cmdConnectRobot()
'Call cmdUnlock()
End Sub
Private Sub Main_MouseHover(sender As Object, e As EventArgs) Handles Me.MouseHover
If P2.Visible = True Then
P2.Visible = False
P1.Visible = True
End If
End Sub
Private Sub P4_Click(sender As Object, e As EventArgs) Handles P4.Click
End Sub
End Class
Another problem I'm facing is that when I call other subs, the user form becomes unresponsive while the sub is running.
I researched and found that I could implement multi threading or async tasks but I'm a bit lost and would be extremely grateful if someone could guide me or point me in the right direction.
Thanks in advance!!
In this case your UI is responsive, however the MouseHover event is only raised once the mouse cursor has hovered over the control for a certain amount of time (default is 400 ms), which is what is causing the delay.
What you are looking for is the MouseEnter event, which is raised as soon as the cursor enters ("touches") the control:
Private Sub P1_MouseEnter(sender As Object, e As EventArgs) Handles P1.MouseEnter
P1.Visible = False
P2.Visible = True
End Sub
You can then use that together with the MouseLeave event on the second picture box to switch back to the non-highlighted image:
Private Sub P2_MouseLeave(sender As Object, e As EventArgs) Handles P2.MouseLeave
P1.Visible = True
P2.Visible = False
End Sub
However switching picture boxes like this is not optimal. I recommend you to look into how you can use Application Resources, then modify your code to only switch the image that one picture box displays.
Here are the basic steps:
Right-click your project in the Solution Explorer and press Properties.
Select the Resources tab.
To add an image either:
a. Drag and drop the image onto the resource pane.
b. Click the arrow next to the Add Resource... button and press Add Existing File....
Now, in your code add this right below Public Class Form1:
Dim ButtonNormal As Image = My.Resources.<first image name>
Dim ButtonHighlighted As Image = My.Resources.<second image name>
Replace <first image name> and <second image name> with the names of your button images.
Now you only need one picture box for the button:
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
P1.Image = ButtonNormal
End Sub
Private Sub P1_MouseEnter(sender As System.Object, e As System.EventArgs) Handles P1.MouseEnter
P1.Image = ButtonHighlighted
End Sub
Private Sub P1_MouseLeave(sender As System.Object, e As System.EventArgs) Handles P1.MouseLeave
P1.Image = ButtonNormal
End Sub
I'll start by saying i'm not a programmer by trade, and i'm sure someone will point out better ways of doing these things, but in regards to the threading question it's fairly simple to implement.
Imports System.Threading
Public Class Form1
Dim WorkerThread As New Thread(AddressOf DoWork)
'WorkerThread' can be any name you like, and 'DoWork' is the name of the sub you want to run in the new thread, and is launched by calling:
WorkerThread.start()
However there is a catch, the new thread is not able to interact directly with the GUI, so you cannot change textbox text etc... I find the easiest way to get changes made to the GUI is to drag a timer onto your form, and have the new thread change variables (pre-defined just below Public Class Form1), then use the Timer1 Tick event to monitor the variables and update the GUI if there are any changes.
Public Class Form1
Dim Iclick, submit
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Iclick.InvokeMember("click")
With WebBrowser1.Document
For l_index As Integer = 0 To ListBox1.Items.Count - 1
Dim l_text As String = CStr(ListBox1.Items(l_index))
.All("input").InnerText = l_text
System.Threading.Thread.Sleep(5000)
Next
'.All("input").InnerText = "http://wordpress.com"
End With
submit.InvokeMember("click")
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
WebBrowser1.Navigate("http://whatwpthemeisthat.com")
End Sub
Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
Iclick = WebBrowser1.Document.GetElementById("input")
submit = WebBrowser1.Document.GetElementById("check")
End Sub
End Class
This is my code so far I have a ListBox with URLs I want to check using web browser which theme are they running (if they are wordpress) but the program seems to be bugged when I click START it is NOT responding, until the last element. It has to do something with the system.threading.thread.sleep line but I don't know what am I doing wrong? Thanks.
That's excactly what the Thread.Sleep() method is for. It freezes for 5 seconds.
Also you are replacing the input each time the For loop repeats. So it replaces, waits 5 seconds, replaces, waits 5 sec... and so on.
I guess you are trying to click the submit button for each of the elements, but that's not what you are doing. You have to hit the submit button each time the text has changed. However you really can't be sure about the loading time of the page.
I'd suggest you to place the submit-part inside the loop, then wait, then go into the next iteration. Maybe you could even try to run the website multiple times, one for each listbox item and then apply the right text to the controls in the webpage, hit the button and receive your result.
EDIT: Your best bet for the Thread.Sleep() would be creating a new thread in which you place the loop. This thread can be paused for 5 seconds, and your application will still respond. This is how you create one:
Imports System.Threading.Thread
Dim myThread as Thread
'//..........
'//Button1 is clicked ->
myThread = new Thread (AddressOf myLoop)
myThread.start()
'//..........
Private Sub myLoop ()
'// Loop goes here...
'Sleeping here will only affect the thread that runs this sub. Your form will still be available
End Sub
I am using this code:
My.Computer.FileSystem.CopyFile(
"Software\Service Packs\WindowsXP\SP2\WindowsXP-KB835935-SP2-ENU.exe",
"C:\Service Pack\WindowsXP-KB835935-SP2-ENU.exe")
Process.Start("C:\Service Pack\WindowsXP-KB835935-SP2-ENU.exe")
This simply copies Windows XP Service Pack from a pendrive to the C Drive located above.
I wish to add a Progress bar to the Form and need the code in order to do this.
Thank you,
Drag a ProgressBar and Timer to the form.
Add the following code under Timer1_Tick event:
Code And Example
Private Sub Timer1_Tick () Handles Timer1.Tick
ProgressBar1.Increment (20)
If ProgressBar1.Value = ProgressBar1.Maximum then
Timer1.Stop
'Add things here you want to do when progressbar reaches maximum.
End If
End Sub
Private Sub Form1_Load () Handles Mybase.Load
Timer1.Stop
End Sub
Private Sub Button1_Click () Handles Button1.Click
Timer1.Start
End Sub
Explanation
The value specified in the ProgressBar1.Increment means the percentage of increase. It will stop increasing when the value is maximum.
The Statement Timer1.Start must be added to the event from which you want to trigger the ProgressBar (Not necessary to write under the Form_Load event).
Hope it works perfectly.
I'm using Visual Basic 2010, and within my form shown sub I need two buttons to be pressed , however I need the first button's code to complete before the moving on to pressing the next button. Is there any way to allow this to happen? Thanks :)
Private Sub Form1_Shown(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Shown
BindingNavigatorMoveLastItem.PerformClick()))
'I need this next button click to be carried out after the one above has completely finished
BindingNavigatorMovePreviousItem.PerformClick()))
End Sub
Use methods instead of "button-clicks":
Private Sub Form1_Shown(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Shown
MoveLastItem()
MovePreviousItem()
End Sub
Private Sub MoveLastItem()
bindingSource1.MoveLast();
End Sub
Private Sub MovePreviousItem()
bindingSource1.MovePrevious();
End Sub
You just have call these methods from the button-click events handlers as well.
Private Sub BindingNavigatorMoveLastItem_Clicked(sender As Object, args As EventArgs) Handles BindingNavigatorMoveLastItem.Click
MoveLastItem()
End Sub
Private Sub BindingNavigatorMovePreviousItem_Clicked(sender As Object, args As EventArgs) Handles BindingNavigatorMovePreviousItem.Click
MovePreviousItem()
End Sub
I must admit I don't do VB, but I came across this page and it might be useful to you.
http://msdn.microsoft.com/en-us//library/system.windows.forms.application.doevents.aspx
If that is not relevant, in your situation I would either use the buttons to set flags and simply if-test the flags, or create a do-while loop so that the code can finish executing while the conditions are met. Careful with those, however, as infinite loops are something they are good at.
Another thought is to enable the second button in the last line of the code of the first button?
Hope something helps. Apologies if it is of no use.