Re: System.threading.timer() question - Visual Basic Discussion Boards

Re: I am a Beginner, could you help please?.

Dave Kreskowiak24-Jun-13 7:17

Dave Kreskowiak

24-Jun-13 7:17

Because his code is an example!

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Re: I am a Beginner, could you help please?.

Member 1011870625-Jun-13 5:16

Member 10118706

25-Jun-13 5:16

Dear Dave,

Many thanks for explaining it to me as well instead of just giving me the code,
My teacher will be impressed haha

Many Thanks

101

Re: I am a Beginner, could you help please?.

Member 1011870625-Jun-13 5:18

Member 10118706

25-Jun-13 5:18

Prissy,

Thank you very much for the code I appreaciate the help im glad Dave explained it to me as this would of been cheating :P Blush | :O

Re: I am a Beginner, could you help please?.

Dave Kreskowiak25-Jun-13 5:32

Dave Kreskowiak

25-Jun-13 5:32

I don't do it any other way! Good Luck!

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Re: I am a Beginner, could you help please?.

Christianirwan26-Jun-13 0:25

Christianirwan

26-Jun-13 0:25

Is it VB 6 or VB .NET? I don't know about return statement in VB 6? I'm forgot to choose Question. Oh, it's a VB .NET Discussion. I don't know. Sorry.

Re: I am a Beginner, could you help please?.

Member 1011870626-Jun-13 2:08

Member 10118706

26-Jun-13 2:08

Haha

System.threading.timer() question

econy19-Jun-13 14:50

econy

19-Jun-13 14:50

I use System.threading.timer() to read RS232 data periodically,
But I found it seems the threading.timer() produces many threads,like each cycle it use a new thread to read.

Is the threading.timer use many threads of threadpool?

Re: System.threading.timer() question

Ron Beyer19-Jun-13 15:03

Ron Beyer

19-Jun-13 15:03

How are you using it? Creating it once then just handling the event, or some other method? Can you post the code where you instantiate it and where you handle it?

Re: System.threading.timer() question

Eddy Vluggen25-Jun-13 10:07

Eddy Vluggen

25-Jun-13 10:07

econy wrote:
But I found it seems the threading.timer() produces many threads,like each cycle
it use a new thread to read.

From the documentation:

MSDN wrote[^]:
System.Threading.Timer is a simple, lightweight timer that uses callback methods and is served by thread pool threads. It is not recommended for use with Windows Forms, because its callbacks do not occur on the user interface thread.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

How to resolve error occurred while installing VB.NET application

Member 1011690819-Jun-13 7:21

Member 10116908

19-Jun-13 7:21

I got error message while installing an VB.NET applicaiton -

"Cannot Start Application

An error has occurred writing to the hard disk. Check if there is enough available space on the disk. Contact the applicaitonh vendor..."

In the Detail, it has -

"ERROR SUMMARY
Below is a summary of the errors, details of these errors are listed later in the log.
* Activation of C:\amldoc1\VB 2003\Project\FTT\publish\NetCommFieldTestTool.application resulted in exception. Following failure messages were detected:
+ Downloading file:///C:/amldoc1/VB 2003/Project/FTT/publish/Application Files/NetCommFieldTestTool_1_0_0_0/Converter.netmodule.deploy did not succeed.
+ The file 'C:\Users\aoum\AppData\Local\Temp\Deployment\K4ZJZGMC.N2C\5045Z1V0.DDV\Converter.netmodule' already exists."

I have tried the solution posted on your site --> Publish - Application Files and select "Include" for all dll files.... still the same error.

Any idea or suggestion?

Thanks for your help!!

Re: How to resolve error occurred while installing VB.NET application

Ron Beyer19-Jun-13 8:27

Ron Beyer

19-Jun-13 8:27

You try clearing out your temporary files before installing?

Re: How to resolve error occurred while installing VB.NET application

Member 1011690819-Jun-13 8:58

Member 10116908

19-Jun-13 8:58

yes, I cleared the temp files under Windows\Temp and Users\(myid)\AppData\Local\Temp... still the same error...

There's "install.log" in then Temp\VSD666.tmp -

"

CSS

The following properties have been set:
Property: [AdminUser] = true {boolean}
Property: [InstallMode] = HomeSite {string}
Property: [ProcessorArchitecture] = AMD64 {string}
Property: [VersionNT] = 6.1.1 {version}
Running checks for package 'Windows Installer 3.1', phase BuildList
The following properties have been set for package 'Windows Installer 3.1':
Running checks for command 'WindowsInstaller3_1\WindowsInstaller-KB893803-v2-x86.exe'
Result of running operator 'VersionGreaterThanOrEqualTo' on property 'VersionMsi' and value '3.1': true
Result of checks for command 'WindowsInstaller3_1\WindowsInstaller-KB893803-v2-x86.exe' is 'Bypass'
'Windows Installer 3.1' RunCheck result: No Install Needed
Running checks for package '.NET Framework 3.5 SP1', phase BuildList
Reading value 'SP' of registry key 'HKLM\Software\Microsoft\NET Framework Setup\NDP\v3.5'
Read integer value 1
Setting value '1 {int}' for property 'DotNet35SP'
The following properties have been set for package '.NET Framework 3.5 SP1':
Property: [DotNet35SP] = 1 {int}
Running checks for command 'DotNetFX35SP1\dotNetFx35setup.exe'
Result of running operator 'ValueGreaterThanEqualTo' on property 'DotNet35SP' and value '1': true
Result of checks for command 'DotNetFX35SP1\dotNetFx35setup.exe' is 'Bypass'
'.NET Framework 3.5 SP1' RunCheck result: No Install Needed
Launching Application.
Application appears to be an application manifest
Launching application manifest via dfshim

"

Any idea?

Thanks for your help!!

Pc names on Network

dineshin198318-Jun-13 23:56

dineshin1983

18-Jun-13 23:56

How to view the list of PC names on the LAN using vb6

Re: Pc names on Network

Dave Kreskowiak19-Jun-13 2:19

Dave Kreskowiak

19-Jun-13 2:19

Step 1: Ditch VB6 and get the free VB.NET Express version of Visual Studio, here[^].

It's VERY unlikely anyone is going to help you with VB6 anymore. It's long been a dead language.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Re: Pc names on Network

Tim Carmichael19-Jun-13 3:33

Tim Carmichael

19-Jun-13 3:33

For starters, I agree with what Dave said... do not use VB6; use a .NET language instead.
Second, rather than simply asking for code, show what you've done and ask for guidance from there.

Tim

Re: Pc names on Network

Eddy Vluggen19-Jun-13 8:58

Eddy Vluggen

19-Jun-13 8:58

Execute the "net view >computers.txt" command, and read the "computers.txt" file.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

Multithread question about VB.NET windows form application

econy18-Jun-13 6:01

econy

18-Jun-13 6:01

Is the VB.NET winform application multithread or single thread?

if I want to use threading.timer in a VB.NET application, do I need pay attention to the MTA, or STA?

Re: Multithread question about VB.NET windows form application

Dave Kreskowiak18-Jun-13 7:26

Dave Kreskowiak

18-Jun-13 7:26

econy wrote:
Is the VB.NET winform application multithread or single thread?

Yes, VB.NET supports free threading.

econy wrote:
if I want to use threading.timer in a VB.NET application, do I need pay
attention to the MTA, or STA?

Doesn't matter unless you are doing/using something COM-related. What are you doing?

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Re: Multithread question about VB.NET windows form application

econy19-Jun-13 14:50

econy

19-Jun-13 14:50

I want to use a thread to read data from serial port periodically

The resolution of System.Timers.Timer

econy17-Jun-13 7:49

econy

17-Jun-13 7:49

I wrote a small program, just want to test DateTime.Now and System.Timers.Timer.

I set Timer interval = 50/40, i.e 50ms/40ms

And in the timer elapsed event, call a StreamWriter.write() function,

tstText = "111" & Space(11) & Format(now, "hh:mm:ss.fff ")
mFileStreamWriter.Write(tstText)

But I found in the text file which stors the data, the timer resolution is 62-65 ms.

01:38:13.423 
01:38:13.485 
01:38:13.548 
01:38:13.610 
01:38:13.673 
01:38:13.735 
01:38:13.798 
01:38:13.860 
01:38:13.923

How can I make the resolution to 50ms, 40ms? or it is impossible to do it in Windows OS or any OS?

Re: The resolution of System.Timers.Timer

Dave Kreskowiak17-Jun-13 8:38

Dave Kreskowiak

17-Jun-13 8:38

Since Windows is not a real-time operating system, and is pre-emptive, and..., and..., getting dead on timer ticks just isn't possible. You can use various tricks to get better resolution, but even those have their limits. A few people have written articles about getting 1us resolution, but nobody has proven they work beyond any doubt.

Under Windows 7 and below, depending on the hardware, the default timer resolution is +/- 15.6ms. This means that a tick will be anywhere within about a ~32ms window of when it's actually supposed to be fired. You can change the resolution down to 1ms, but it's system-wide change that effects everything running on the system, not just your app. See this[^] for more info.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

How to set StreamWriter object be null

econy17-Jun-13 4:10

econy

17-Jun-13 4:10

After some operations, I want to set the StreamWrite object be NULL.

Now the code I wrote as follows:

mFileStreamWriter.Flush()
mFileStreamWriter.Close()
mFileStreamWriter = Nothing

But MSDN said is/isNot only used to compare the reference, not value.
So = Nothing means let an object refer to Nothing, right?

Re: How to set StreamWriter object be null

Dave Kreskowiak17-Jun-13 5:25

Dave Kreskowiak

17-Jun-13 5:25

Nothing in VB.NET is null in other languages.

You don't have to set the streamwriter to Nothing. It does nothing for you at all.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Use Dispose

David Mujica17-Jun-13 8:50

David Mujica

17-Jun-13 8:50

If you want to ensure that the resources are released, then you should "Dispose" of the StreamWriter.

http://msdn.microsoft.com/en-us/library/system.io.streamwriter.dispose.aspx[^]

Use Using

Richard Deeming17-Jun-13 9:09

Richard Deeming

17-Jun-13 9:09

If the StreamWriter is a local variable which never escapes the current method, wrap it in a Using ... End Using[^] block. This will ensure that the Dispose method is always called, even if your code throws an exception.

Using stream As Stream = File.OpenWrite("path\to\your\file.txt")
   Using sw As New StreamWriter(stream)
      ...
      ' NB: No need to call Flush or Close here.
   End Using
End Using

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.