I can't get latest value by ref parameter. WHY? [modified] - C# Discussion Boards

Henry Minute12-May-09 11:54

12-May-09 11:54

It is the double quote thing for Extended Properties that is causing the problem.
In order to get a quotation mark within a literal string you have to 'escape them'
This means that the double quotes in the middle have to look like \"\", for them to be recognised as quotes within a string.
When this is all over look up Escape Characters for a better explanation.

In the mean time take a look at ADO Connection Strings[^], for some examples. Search in the article for 'Extended Properties' and you'll see what I mean.

Have a play.

Good Luck! Smile | :)

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.”

Re: Working with multiple forms

bwood202013-May-09 4:02

bwood2020

13-May-09 4:02

Thank you Henry for all your help. I will look into this today.

Re: Working with multiple forms

bwood202013-May-09 6:20

bwood2020

13-May-09 6:20

Hi Henry,

I have read a couple articles on escape sequences and have tried to include the same line of code(just modified to fit what I need) and I still get errors. Maybe I am looking in the wrong place but when I try and use
Extended Properties=\"\"text;HDR=Yes;FMT=Delimited(" + gds + ");\"\";"; it says I need to add ";". But when I add one it tells me I need to add another. However, if I were to plug the line of code above into the code found in the Code Project page it seems fine. I think what is happening is that there is something wrong with the first part of the connection string, maybe the Source.

"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path.GetDirectoryName(FilePath) + @";

Could you look at this one more time for me and point me in the right direction when you have time please? Here is the entire connection string:

String comString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path.GetDirectoryName(FilePath) + @";Extended Properties=\"\"text;HDR=Yes;FMT=Delimited(" + gds + ");\"\";";

Thank you,

Brenton

Re: Working with multiple forms

Henry Minute13-May-09 6:38

Henry Minute

13-May-09 6:38

I have found an article that is doing what I think you are trying to do.
Read text file (txt, csv, log, tab, fixed length)[^], it only uses one \" instead of two.
Have a look and see if it helps.

Re: Working with multiple forms

bwood202014-May-09 9:49

bwood2020

14-May-09 9:49

That did it Henry. Thank you so much. Is there something I need to do is far as closing this out or giving you a rating? Let me know and I will come back.

Re: Working with multiple forms

Henry Minute14-May-09 10:46

Henry Minute

14-May-09 10:46

Thanks for the thanks!
If you would just vote one of my posts as a 5, then people will know that your question has been answered.

Good luck! Smile | :)

Re: Working with multiple forms

DaveyM6912-May-09 8:09

DaveyM69

12-May-09 8:09

Sorry, I was using automatic properties which may not be available in the version that you're working with.

Follow Henry's advice and use a private member variable that the property getter and setter accesses.

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus)

I can't get latest value by ref parameter. WHY? [modified]

codeadair12-May-09 5:26

codeadair

12-May-09 5:26

There are two layers in my project. one is business layer,and the other is UI layer.
In UI layer, i invoke the method 'SaveInfo' of business layer. by the way ServiceActivator.GetService.

But i can't get 'newInfo' in UI layer.
and if i remove 'throw ex;' in 'SaveInfo' method. i could get it.
i don't know why.
do you know? how could i get newInfo if i want to throw Exception to UI layer.
pls. ths.

'SaveInfo' in Business layer:
public void SaveInfo(ref StudentInfo info,ref List<studentinfodetail> detailList,string strType)
{
try
{
...
info = newInfo;
detailList = newDetailList;
throw new MyException("Information already exist.");
...
}
catch(Exception ex)
{
throw ex;
}
}

the invoke code in UI layer:

try
{
...
mMyDs.SaveInfo(ref curInfo,ref curList,"Add");
...
]
catch(MyException mex)
{
textBox1.text = curInfo.Name;
}
catch(Exception ex)
{
}

MSN:msnadair@hotmail.com
Skype:skyadair

modified on Tuesday, May 12, 2009 8:52 PM

Re: I can't get latest value by ref parameter. WHY?

Henry Minute12-May-09 5:39

Henry Minute

12-May-09 5:39

I have to say that returning to a calling process by throwing an exception is not the normal way to do it.
It would be better to give SaveInfo() a return type of bool and instead of throw new MyException use return true;.

Then in your calling code use

if (mMyDs.SaveInfo(ref curInfo,ref curList,"Add"))
{
    // do whatever you want if all is well
}
else
{
    // do whatever you want when it goes bad. e.g. throw an exception
}

Re: I can't get latest value by ref parameter. WHY?

codeadair12-May-09 14:57

codeadair

12-May-09 14:57

No,i can't. i need to do this.
i should return the latest data from database if the info already exist. and the info may have different status, i should throw out the hint.

MSN:msnadair@hotmail.com
Skype:skyadair

Several event handlers, one handler function, how to know which event handler has been used??

blackhattrick12-May-09 5:23

blackhattrick

12-May-09 5:23

I have a serial ports list. I declared it like this:

<br />
private List<SerialPort> lstSerialPorts;<br />
<br />
for (int i = 1; i<=cont; i++)<br />
{<br />
    SerialPort tempPort = new SerialPort("COM" + cont.ToString(), 2400);<br />
    lstSerialPorts.Add(tempPort);<br />
    lstSerialPörts[i].DataReceived += SerialDataReceivedEventHandler(TEST_FUNCTION);<br />
}<br />

My TEST_FUNCTION is empty so far:

<br />
<br />
void TEST_FUNCTION(object sender, SerialDataReceivedEventArgs e)<br />
{<br />
            throw new NotImplementedException();<br />
}<br />

As you can see, all serial ports have the same handler function. How could I check which serial port triggered the TEST_FUNCTION? It would be great something like this:

<br />
void TEST_FUNCTION(object sender, SerialDataReceivedEventArgs e)<br />
{<br />
      Console.WriteLine("This function was triggered by: {0}",anUnknownVariable);<br />
}<br />

Parameter "e" does not have any useful property or function

Any help would be apreciated and excuse me about my English if I made a mistake Smile | :)

Ivan

Re: Several event handlers, one handler function, how to know which event handler has been used??

DaveyM6912-May-09 5:29

DaveyM69

12-May-09 5:29

You've looked at the e parameter - now try the other one!

The clue is in the name 'sender'. Cast it to a SerialPort from object and you now have the object that raised the event.

Re: Several event handlers, one handler function, how to know which event handler has been used??

Samer Aburabie12-May-09 5:32

Samer Aburabie

12-May-09 5:32

Use the sender object, cast it to SerialPort and you will get the object who triggered the function.

Sincerely Samer Abu Rabie

Imagination is more important than knowledge !

Re: Several event handlers, one handler function, how to know which event handler has been used??

OriginalGriff12-May-09 5:34

OriginalGriff

12-May-09 5:34

If 'e' is not a lot of use, have you considered looking at 'sender', by any chance?

If you expand it in the debugger, you may find it is a SerialPort object.

No trees were harmed in the sending of this message; however, a significant number of electrons were slightly inconvenienced.

This message is made of fully recyclable Zeros and Ones

Re: Several event handlers, one handler function, how to know which event handler has been used??

blackhattrick12-May-09 5:53

blackhattrick

12-May-09 5:53

Thx a lot guys Smile | :)

Re: Several event handlers, one handler function, how to know which event handler has been used??

riced12-May-09 7:43

riced

12-May-09 7:43

I know your proble is solved but something I noticed in the code and wondered if it was correct.
Should new SerialPort("COM" + cont.ToString()
be new SerialPort("COM" + i.ToString()?

Good of you to thank the guys. Not everyone does. Smile | :)

Regards
David R
---------------------------------------------------------------
"Every program eventually becomes rococo, and then rubble." - Alan Perlis

Re: Several event handlers, one handler function, how to know which event handler has been used??

blackhattrick12-May-09 15:24

blackhattrick

12-May-09 15:24

Yeah my mistake typing that... Thanks!

Programatically download file (script problem)

Niemand2512-May-09 5:13

Niemand25

12-May-09 5:13

I want my application to programatically download a file from skydrive.live.com,
but I encountered a problem:

Microsoft uses script for file download that makes it impossible to download the file using WebClient (at least as far as I know). Could somebody help to find a workaround on how to download the file?

The microsoft's script is:

Download

var $SelfPage = new function()
{
var _download = 'http\x3a\x2f\x2f5odcbq.bay.livefilestore.com\x2fy1pi19dAInfgawlhjDTcs2sbdCJEkvL7jzsz8SVx9qA-EiQwX-ZPeg-DCt63IEoNWu7USu9uUA-j9FkUosBKqU-3Q\x2fApskaita_1.1_beta_update.exe';
var _demote = 'http\x3a\x2f\x2f5odcbq.bay.livefilestore.com\x2fy1pi19dAInfgawlhjDTcs2sbdCJEkvL7jzsz8SVx9qA-EiQwX-ZPeg-DCt63IEoNWu7USu9uUA-j9FkUosBKqU-3Q\x2fApskaita_1.1_beta_update.exe';
var _dirty = false;

this.MarkDirty = function() { _dirty = true; }
this.Download = function()
{
if (_dirty)
{
_dirty = false;
window.location = _demote;
}
else
{
window.location = _download;
}
}
}

HELP with assignment

sofi7912-May-09 5:00

sofi79

12-May-09 5:00

Hi I don't know if anyone could help me. I'm beginner on C# programing and I have an assignment to finish and i don't know how to finish!!!
I started creating a program with a menu with options to creates a new file and read the new file. The files that I create have an boundary limits(not less than 125 and no more than 350 characters in number) and after creating and saving the file there is an option to go to main menu. This is the part that I've done. Now I have to after writting on the new file create an option to encript and save the file and when opening the file it should have another option to go back to plain text format(decrypt). The encryption should be represented as numbers grouped in pairs, and it should create alternate numbers(written twice). for some single letters ( the most common ones a,e,o,r,t), also using null characters I have to include some mechanism for introduce spaces!!! I really apreciate if anyone could help me with some suggestions,
Thanks

Re: HELP with assignment

EliottA12-May-09 5:09

EliottA

12-May-09 5:09

I would encrypt using built in encryption classes like Rijndael-Managed, what is it you want to do, exactly?

Check out the CodeProject forum Guidelines[^]

Re: HELP with assignment

sofi7912-May-09 5:14

sofi79

12-May-09 5:14

I'm on my first year of C# i've learnt all the basic but I don't know how to encrypt or decrypt any message, that is my biggest problem. Really I don't know how to convert characters to integers,
Thanks for your help Smile | :)

Re: HELP with assignment

DaveyM6912-May-09 5:20

DaveyM69

12-May-09 5:20

sofi79 wrote:
don't know how to convert characters to integers

Convert.ToInt32(char)[^]

Re: HELP with assignment

PIEBALDconsult12-May-09 5:25

PIEBALDconsult

12-May-09 5:25

sofi79 wrote:
I don't know how to convert characters to integers

Probably because it's so simple:

char c = 'a' ;
int i = c ; // Char to int
System.Console.WriteLine ( i ) ;
 
c = (char) i ; // To get back to a char

I'd be interested in hearing more about this simple encryption process.

Re: HELP with assignment

Dan Neely12-May-09 6:00

Dan Neely

12-May-09 6:00

I always assumed I needed an explicit Convert calls here. Learn something new everyday. Cool | :cool:

It is a truth universally acknowledged that a zombie in possession of brains must be in want of more brains.
-- Pride and Prejudice and Zombies

Re: HELP with assignment

PIEBALDconsult12-May-09 7:03

PIEBALDconsult

12-May-09 7:03

The Convert class is evil; don't use it.

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