C# Discussion Boards - CodeProject

mmjf969628-Jan-10 2:37

28-Jan-10 2:37

I am able now to get my data from the column in my database that I want into my combo box. However I want one thing to display in the combo box and when that item is selected I would like the value from a different column but same row to show up in a text box. I can get this to work sometimes I just don't understand how it is working. I am using data binding and I would like a tutorial that walks me through how this works.

Now that I have my combo box displaying the data I want from my database and that I have my text box displaying the correct data from my database when an item is selected in the combo box. I would like to take the number showing in my text box and multiply it by a number I input in a text box I will call "quantity". Then have the calculation show up in a separate text box called "total".

Do you have any advice on this or examples?

Re: Access Database

Roger Wright28-Jan-10 17:59

Roger Wright

28-Jan-10 17:59

The combobox shows the selection now, if I understand you correctly, so you are able to access the data you wanted. And if I recall, you have an associated value of calories displayed in the textbox. Is that correct? Now you want to enter a quantity of the item in another box, multiply them, and display the total calories. Have I got that right?

Since a textbox only holds text data, the first thing you'll need to do is cast their contents to numeric values:

Int32 Cals = System.Convert.ToInt32(txtCals.Text);<br />
Int32 Qty = System.Convert.ToInt32(txtQuantity.Text);

Then you need to perform the calculation and convert the result to text to store it in the result textbox:

txtResult.Text = System.Convert.ToString(Cals * Qty);

I make no guarantees, since I'm new to C# and .Net, but I believe this will get you on your way again. Let me get a few chapters ahead of you and I might be able to help with the database part. Big Grin | :-D

"A Journey of a Thousand Rest Stops Begins with a Single Movement"

Re: Access Database

mmjf969629-Jan-10 2:22

mmjf9696

29-Jan-10 2:22

That is right I will give this a try thanks. Do you know of any good C# help sites that might have videos or code examples?

Re: Access Database

Roger Wright29-Jan-10 2:30

Roger Wright

29-Jan-10 2:30

As a matter of fact, I do! You're already a member. Big Grin | :-D

Spend a bunch of time in the Articles section here; there's a lot of excellent code examples, many with clear, informative explanations. I haven't seen any better resource.

"A Journey of a Thousand Rest Stops Begins with a Single Movement"

Re: Access Database

mmjf969629-Jan-10 8:21

mmjf9696

29-Jan-10 8:21

Great I will start my search today. I just want to get better at the basics before I move up to the big boy stuff. Thanks for you advice and help.

How to read binary file with dvi extension.

T-Joe27-Jan-10 12:48

T-Joe

27-Jan-10 12:48

Hi? I have a problem. I got the file which has dvi extension. Of course i can use some application but problem is i want to create my own application.
Please help me and guide me how to read the binary file with dvi extension.

Re: How to read binary file with dvi extension.

harold aptroot27-Jan-10 12:59

harold aptroot

27-Jan-10 12:59

There are a lot of details about the internal structure (mostly a list of commands in binary form) of such files here: http://www-users.math.umd.edu/~asnowden/comp-cont/dvi.html[^]

Re: How to read binary file with dvi extension.

DaveyM6927-Jan-10 13:00

DaveyM69

27-Jan-10 13:00

You need to research the file format so you can parse it correctly. This[^] may help

Dave

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Why are you using VB6? Do you hate yourself? (Christian Graus)

application start from file open request?

Mark H Bishop27-Jan-10 11:29

Mark H Bishop

27-Jan-10 11:29

I have an application where the user sets-up a workspace. The workspace has a variety of elements including arrays, bitmaps, generic lists, etc. When the user is done working he/she can save the workspace. The application saves the elements in a sequenced, binary file. When the user comes back, he starts the application and loads the workspace through an “open” menu item. It works.

Now, some users instinctively navigate to the file and double-click to both start the application and load the file. I’m all set with setting the default app for the extension and all that. But, what is the standard procedure for instructing the application to load the selected file if it has opened by way of a file double-click?

Re: application start from file open request?

Luc Pattyn27-Jan-10 12:20

Luc Pattyn

27-Jan-10 12:20

when you double-click a file in Windows Explorer, it will launch the application associated with the file extension, and pass the full path as the first command line parameter (or several if several files were selected). So let your app look for command line arguments, and if there are any, open them.

Either use the optional parameters of the Main() method, or use the Environment class to get the command line.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
[The QA section does it automatically now, I hope we soon get it on regular forums as well]

Re: application start from file open request?

Dan Mos27-Jan-10 12:22

Dan Mos

27-Jan-10 12:22

Spuose your app displayes images. You set the default "open with and all that" to your app.

Then in program.cs inside Main after Application.Enable.... do something like this:

if(args!=null){
  Application.Run(new MyCoolImageViewer(args[0]);
}
else{
  Application.Run( new MyCoolImageViewer(null);
}

And of course in your ctor check for null before opening the image.

Re: application start from file open request?

Mark H Bishop28-Jan-10 9:48

Mark H Bishop

28-Jan-10 9:48

Neat. Thanks!

Form Not Closing

Wamuti27-Jan-10 11:10

Wamuti

27-Jan-10 11:10

I have this function that is called from the constructor of the main form:

private void InitNet()
{
     listener= new TcpListener(localAddress, portNo);
     listenForConnection  = new Thread(StartListening);
     listenForConnection.Start();
     Control.CheckForIllegalCrossThreadCalls = false;
}

The StartListening function is defined as follows:

private void StartListening()
{
      listener.Start();
      while (true)
      {
           Networks user = new Networks(listener.AcceptTcpClient());
      }
}

When i close the program, it does not get out of memory, possible because of the thread. I have tried to abort the thread in the FormClosing Event but this did not work, how can i close this application competely (Of course not using task manager! Poke tongue | ;-P

)

Wamuti: Any man can be an island, but islands to need water around them!
Edmund Burke: No one could make a greater mistake than he who did nothing because he could do only a little.

Re: Form Not Closing

DaveyM6927-Jan-10 11:13

DaveyM69

27-Jan-10 11:13

Wamuti wrote:
CheckForIllegalCrossThreadCalls = false;

Evil OMG | :OMG:

Dave

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Re: Form Not Closing

Jimmanuel27-Jan-10 11:22

Jimmanuel

27-Jan-10 11:22

You need to tell the thread to stop so that it can cleanup its resources and exit:

[RE-EDIT]

bool runListener = true;
private void StartListening()
{
      listener.Start();
      while (runListener)
      {
           if (listener.Pending())
           {
                 Networks user = new Networks(listener.AcceptTcpClient());
           }
           else
           {
                 Thread.Sleep(250); // sleep for a bit to not hog the processor
           }
      }
      listener.Stop();
}

then in the FormClosing event (or wherever you're doing cleanup) set runListener to false.

Also, if you set the thread's IsBackground property to true then the thread won't cause the program to remain alive even if it isn't terminated before the form closes.

Control.CheckForIllegalCrossThreadCalls = false;

And that's just completely uncalled for.

Badger | [badger,badger,badger,badger...]

Re: Form Not Closing

Wamuti27-Jan-10 11:29

Wamuti

27-Jan-10 11:29

Thanks. It worked.

Wamuti: Any man can be an island, but islands to need water around them!
Edmund Burke: No one could make a greater mistake than he who did nothing because he could do only a little.

Re: Form Not Closing

Jimmanuel27-Jan-10 11:35

Jimmanuel

27-Jan-10 11:35

Glad to help Smile | :)

Re: Form Not Closing

Wamuti27-Jan-10 11:39

Wamuti

27-Jan-10 11:39

Thanks again for the optimization. Thumbs Up | :thumbsup:

Wamuti: Any man can be an island, but islands to need water around them!
Edmund Burke: No one could make a greater mistake than he who did nothing because he could do only a little.

Sppech to text & Text to speech

SajjadZare27-Jan-10 9:08

SajjadZare

27-Jan-10 9:08

Hi to all
I need a component for convert text to speech and speech to text

Re: Sppech to text & Text to speech

Jimmanuel27-Jan-10 9:42

Jimmanuel

27-Jan-10 9:42

clickety[^]

help

hu_kh0027-Jan-10 8:20

hu_kh00

27-Jan-10 8:20

Hello
can help me in my problem.I need deal with very big number to add,sub,multi and divide I can do the add,sub and multi but can't do the divide can help me.
I need divide very long integer number such that
x=444444444444444444444444444444444444444444444444444444444444444444444444
y=3333333333333333333333333333333333333333333333333333333

or more that each number consist from more of 300 digit can I divide it and result is div and mod.

thanks.

Re: help

hammerstein0527-Jan-10 8:39

hammerstein05

27-Jan-10 8:39

I can't see any possible application for that sort of number crunching. What is a 300 digit integer anyway?

Look at the maximum sizes of the datatypes, you're going to find you can't actually store numbers that big.

Re: help

hammerstein0527-Jan-10 9:39

hammerstein05

27-Jan-10 9:39

Apologies for a severely lacking knowledge of the datatypes. At least I can go home today knowing I learnt something.

Re: help

DaveyM6927-Jan-10 12:11

DaveyM69

27-Jan-10 12:11