run application in back ground
hi all
i have prepared an application which dose not take any user input and the aim of the application is to take screenshots at a regular interval of 5 min
i am using vb.net 2005
for this i have taken a form and in that form i have placed a timer control and in timer trick i am calling the function which takes the screen shot
my requirement is to set up this application and this should run in the back ground and the user should not be able to cancel or stop the running of the application
can any one suggest me how to do this the application should run in the background it self and this should start when ever the system boots
I would say a service is not the right approach for this - since the implementation requires a logged in user to function. Make it startup when the user logs on, put an icon in the system tray to allow the user to start/stop the capture, and have your actual program have no interface (or a simple 'about' box, so they know what the icon is actually doing). If you already have the form, simply don't show it (use a 'sub main' function to start you application with the form invisible).
The application shortcut can be placed in the startup folder or the 'run' registry key.
So you need to add several things:
- Hide the form on startup - use sub main and Application.Run(MyForm)
- Create a system tray icon, with a context menu
- Add the program shortcut to the Run registry key or startup folder - this is usually done at installation, which means you need an installation package.
You don't necessarily want the user to be logged on... To allow service to interact with the desktop, you'll have to check the "Allow service to interact with desktop" option in your service's options. Then, program your service application, that it only takes snapshots if a user is logged on...
Doing it this way, the service will always starts on windows boot and will take desktop snaps no matter who is logged on... And it would act invisible for a regular desktop user...
Andrej
I agree, a service is the way to do this kind of app.
You should realize that anyone with local administrative access on the computer and with a little bit of knowledge about how Windows works will be able to disable the program rather easily. The only way to prevent this without removing local admin access from your users would be to go a lower level route such as a rootkit. Even this can be removed although it is quite a chore. I wouldn't recommend this unless your project goal is to create a nasty spyware/malware app.
If you need to take screenshots for multiple users, then you can, of course write this as a service. I would still say that such an application should not be a service - we have far too many services as it is. Particularly an application which takes screenshots is not necessarily a user-friendly application.
It really depends on the application. What you have described doesn't necesarily mean 'service' you have to decide if it's appropriate. If the reason to run it as such is to prevent a user from disabling it, then you have more serious problems.
i have decided to make it as a service
in the service i have taken one timer control from the component tab and in time trick event i have called the function which takes the screen shot
and in service start i have decided set timer1.enabled="True"
and in service stop i have set timer1.enabled="False"
but my problem is the timer is not workin in my service
as we cannot debug the service i am un able to see weather the service timer trick is firing or not
but i am sure that service is getting started
preparing a service is a good idea but timer control is not working in the service
Imports
System.IOImports
System.DrawingImports
System.Windows.FormsProtected
Overrides Sub OnStart(ByVal args() As String)' Add code here to start your service. This method should set things' in motion so your service can do its work.Timer1.Enabled =
TrueEnd SubProtected Overrides Sub OnStop()' Add code here to perform any tear-down necessary to stop your service.Timer1.Enabled =
FalseEnd Sub.Private Sub Timer1_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Timer1.Tickscreenshot()
End Sub
i am using the above code in the visual studio 2005 in the windows service
but unfortunately the timer control is not getting activated
and the function screenshot() is not getting run
as i cannot see the debuging of service i am unable to track where the problem is
can any one help in this please
Sorry I can't help, but I would be real interested to see the code for the screenshot function.
Rajesh,
you'd have to use a different kind of timer, e.g. System.Threading.Timer... here's the complete service code I've quickly put together...:
Imports
System
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Windows.FormsPublic Class ScreenLoggerService
Private myTimer As Threading.Timer
Private timerDelegate As Threading.TimerCallback
Protected Overrides Sub OnStart(ByVal args() As String)
timerDelegate = New Threading.TimerCallback(AddressOf Tick)
myTimer = New Threading.Timer(timerDelegate, Nothing, 0, 10000)
End Sub
Protected Overrides Sub OnStop()
myTimer.Dispose()
End Sub Private Sub Tick(ByVal state As Object)
Dim image As New Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height,
PixelFormat.Format32bppArgb)
Dim g As Graphics = Graphics.FromImage(image)
g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy)
image.Save("c:\" + DateTime.Now.ToString("yyMMddhhmmss") + ".png", ImageFormat.Png)
End Sub
End ClassIn the above code, the screen snapping interval is set to 10 seconds (10000 ms). Change this value in the "my Timer = New Threading..." line.
Hope this helps,
Andrej
this is showing a following exception of "the handle is invalid"
when i start the service
in the following line
g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy)
the exception details are as follows
please help me in solving this exception
System.ComponentModel.Win32Exception was unhandled
ErrorCode=-2147467259
Message="The handle is invalid"
Source="System.Drawing"
StackTrace:
at System.Drawing.Graphics.CopyFromScreen(Int32 sourceX, Int32 sourceY, Int32 destinationX, Int32 destinationY, Size blockRegionSize, CopyPixelOperation copyPixelOperation)
at WindowsService1.ScreenLoggerService.Tick(Object state) in C:\Documents and Settings\brajesh\Desktop\WindowsService1\WindowsService1\Service1.vb:line 22
at System.Threading._TimerCallback.TimerCallback_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading._TimerCallback.PerformTimerCallback(Object state)
Make sure you checked the "Allow service to interact with desktop" option on your service's Log On option tab (Log On as Local System account), before you started the service.
Andrej
please help me to solve this problems
1. i should make the service run automatically what should i do
2.is it necessary to login as the admininstrator in order to install the service
3. my requirement is to make the service run when any user login to the system
what i have done is
i have installed the service and i am getting the screen shots
but
each time when i shutdown and restart the service is not running automatically
and
i am not getting the screen shots of the other user who is using this system and loged on with his user name and passwword
Could it be that your service is crashing? Try wrapping your screensnapping code with the Try...Catch block. To make the Service run automatically, set its startup type to Automatic.
Andrej
i have installed the screenlogger service in my login it is working fine and i am not the administrator of the system
but
when some other user login with different username and password the screen logger is not working
i have kept the service start type to automatic but it is not starting automatic when ever the system is booted
can i prepare a set up file to my screenlogger service so that it will gets installed like other window application programs if so how
