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That code dump is not formatted and unreadable, please edit your message and add PRE tags.
ivo75 wrote: Why my program "sleep"
You probably mean the GUI freezes (i.e. high CPU load, no Form resize/repaint; a sleeping program would not cause any CPU load), which would suggest you have too much going on in some event handler; if so, the solution is using one or more additional threads (Thread, ThreadPool, BackgroundWorker, etc).
Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum
Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.
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I insert in SQL statment another SQL statment maybe for this is hapent this.
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Your SQL operations really are too complex, and hence will take too long, to run them on the main thread. I suggest you use a BackgroundWorker and use its progress reporting to update the GUI (the DoWork handler itself is not allowed to touch the GUI Controls!).
Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum
Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.
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give me some example how to use BackgroundWorker
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Of course, Sir. Here you go, Sir: examples[^].
Anything else you require, Sir?
Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum
Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.
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Thanks
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Hi,
I am printing Crystal reports via VB.Net. Some of the printers are set to print duplex others are not. I want to set the printers duplex option to off when ever I run the code. What is the best way of doing this. What do I have to import/do to achieve this? I have tried importing SystemManagement but no success. What am I doing wrong. Any sample would be welcome.
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Well you should definitely be able to do it using WMI and the Win32_PrinterConfiguration[^] structure.
This[^] thread on MSDN has the basics.
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
I wouldn't let CG touch my Abacus!
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Thanks for the speedy reply.
How would this code/structure be displayed on the project.
Sorry for this.
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Central_IT wrote: How would this code/structure be displayed on the project.
Normally it wouldn't be 'displayed' so I am a little confused by your question.
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
I wouldn't let CG touch my Abacus!
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Hi,
I think I am getting mixed up. The question I meant was "How can I set the code so that my printer does not print duplex"
What is the syntax and what class do I import. It has been a long time since I did any real coding and I am a wee bit rusty. You can properly tell with this question...getting old.
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If you click on the second link in my first reply and scroll down to the answer from 'JWolf011' and look at the code he has posted.
You have not show us the code you are using so I cannot tell you exactly where you should put that code but for an example suppose that you have a Button to turn off Duplex. Double-click the Button to get the template for its Click handler in your code window.
Inside the new handler type the code from that link (leave out the two Debug.Print lines, if you like and you must change mo.SetPropertyValue("Duplex", True) to mo.SetPropertyValue("Duplex", False)).
Then when you run your application and click that Button it should turn off Duplex. Then do your normal printing.
If it works then move the code into your normal print routine.
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
I wouldn't let CG touch my Abacus!
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I tend to install duplex capable printers twice, once for simplex, and once for duplex. Then it is all a matter of choosing the right printer.
Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum
Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.
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Hi all
I have a ms access database with few tables. I nned to draw a graph/chart using the tables in excel.
Is it possible to do with vb.net coding?
If possible, any suggestion and references will be very much helpful.
Thanks in advance.
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Thanks for the link.
Will checkout.
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I have combo box that is loaded dynamically. When the user select Misc from the list I want to unhide a text field. I recived the following error.
System.NullReferenceException: Object reference not set to an instance of an object.
at ACEPackaging.dlgEditSkidWeight.HideCarrerTextBox()
etc
etc
etc
Here is my code that is called when the user changes the selection on the combobox.
If CStr(cboCarrier.SelectedValue.ToString) = "99" Then
tbCarrierDesc.Visible = True
Else
tbCarrierDesc.Visible = False
End If
End If
I did a little research and said that this error is caused by the .ToString being Null or Nothing. So here is what I have added to correct the problem so there are no more errors. Please let me knwo if this will work.
If Not cboCarrier.SelectedValue.ToString Is Nothing Then 'added this line
If CStr(cboCarrier.SelectedValue.ToString) = "99" Then
tbCarrierDesc.Visible = True
Else
tbCarrierDesc.Visible = False
End If
End If
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ToString being Nothing wouldn't cause that problem... More likely, SelectedValue is the problem. Also, Using CStr on something that's already gone through ToString is redundant... A better way would be:
If Convert.ToString(cboCarrier.SelectedValue) = "99" Then
tbCarrierDesc.Visible = True
Else
tbCarrierDesc.Visible = False
End If
As Convert.ToString can handle a null/Nothing argument, and would just return "".
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What if the object hasn't been set?
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If SelectedValue is nothing, Convert.ToString will return an empty string.
If the object itself is nothing, you'll still get the error... But I'm assuming this is just a named control, which would be set as soon as the window/form is instantiated.
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Assuming your ComboBox list does not hold any item that is Nothing, this should do:
tbCarrierDesc.Visible = cboCarrier.SelectedIndex >= 0 AND cboCarrier.SelectedValue.ToString = "99"
Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum
Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.
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CStr(cboCarrier.SelectedValue)
Won't throw an exception.
cboCarrier.SelectedValue.ToString
Might throw an exception if SelectedValue is Nothing, since you can't call a method on an object if the object isn't there.
Hence, we can say;
CStr(cboCarrier.SelectedValue.ToString)
Might throw an exception, since the ToString will be evaluated prior to the CStr function.
I are Troll 
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Dear all,
I am rather new to the exciting world of software development (i do not consider myself a developer but merely a visitor in the field) and have some fundamental questions to express in order to make things strait in my mind.
I would like someone to answer the general steps in developing an application.
In my mind the steps would go something like:
1. Analyzing the needs of the solution and prepare any relevant documentation on the to-do stuff.
2. Recognize the new classes that has to be developed (based on the previous analysis) in order to achieve the required functionality
3. Develop the code & tight the variables and relevant documentation (help docs etc)
4. Test the code for possible errors (internal test) and return to step 3 for any changes
5. Issue the final release
Questions:
1. Are these steps correct?
2. Is it a necessity to develop new classes? Couldn't one use already developed classes or just subs and functions reside in some modules?
3. What percentage of total-time would each one of the development phases take?
Best Regards
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Hi,
You are correct to some extent. You can move on to develop a software following the steps :
1. Analyzing the needs of the solution and prepare any relevant documentation on the to-do stuff. (Requirement Gathering)
2. Identify the Design Pattern, Technology etc. to be used for the development considering the scenario, requirements.
3. Once you are done with this, you can move on to prepare the prototype of the application. i.e. The general skeleton of the
working model of the software.
4. Develop the code with OOP concepts. i.e. Modularity, Re-usability etc.
5. Test the code as you develope. It is a good habit to test the code at every level.
6. Give the first release to the client. (User Acceptance Testing)
7. Let client evaluate your software. If they are ok with the functionality and everything, Prepare the final release (GO Live!!!!)
For more info refer :
http://www.exforsys.com/tutorials/programming-concepts/software-development-life-cycle.html[^]
Is it a necessity to develop new classes? Couldn't one use already developed classes or just subs and functions reside in some modules?
Ans : Software Developers follow the principle of Re-usability. i.e. You develop the modules in such a way that they can be used from some other
applications also. It reduces the time needed to develop the softwares. You should not start from scratch always. Always look for the
pre-developed components and make use of them.
What percentage of total-time would each one of the development phases take?
Ans : There is no clear answer to this question. It totally depends on the size of the software. Sometimes it is task of month, sometimes even
the years are less to complete the development.
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Since Pravin has already set some things straight I'll just tell you this, with your 5 point plan you've already shown me to be a candidate to be a good developer someday. I deal with people that think they are developers on almost a daily basis and they still haven't grasped the concepts you roughly outlined.
My advice to you: Never stop learning, never stop improving on your skills! 
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