Re: C# Database question - C# Discussion Boards

XML Dataset and Removing Rows...

3-Nov-02 9:35

<winsysdir>\msdxm.ocx (the only static dependency is quartz.dll (DirectShow actually).

I have the 6.4 version because indeed I've never upgraded WindowsMedia (for god sake, I don't want a play behave like a turtle!).

I don't know about other releases. An educated developer would check out the public MS NGs for this topic.

Now I remember the NDA MS sent me a couple of years ago when I wanted to distribute a windows-media based app. Scaring, those 40 printed pages looked like my testament. Eek! | :eek:

Back to real work : D-27.

hammackj2-Nov-02 18:08

hammackj

2-Nov-02 18:08

I can not seem to get a record/row to delete from my XML file, my code for removing is this.

	<br />
private void button5_Click(object sender, System.EventArgs e)<br />
		{<br />
			//remove code<br />
			try<br />
			{<br />
				row = lstAccounts.SelectedIndex;<br />
<br />
				lstAccounts.Items.RemoveAt(lstAccounts.SelectedIndex);<br />
				<br />
				ds.Tables[0].Rows[row].Delete();								<br />
				ds.GetChanges();<br />
				ds.Tables[0].Rows[row].AcceptChanges();<br />
				//--row;<br />
				<br />
			}<br />
			<br />
			catch (Exception p)<br />
			{<br />
				MessageBox.Show(p.Message);<br />
			}<br />
		}<br />

I am trying to remove this code from a Complex type XML file. for some reason the brackets are removed from the code =\

<br />
 <Account><br />
    <UserName>Please enter your name.</UserName><br />
    <UserEmail>Please enter your E-mail.</UserEmail><br />
    <LogonName>Please enter your E-mail Account name.</LogonName><br />
    <Password>Please enter your E-mail Password</Password><br />
    <AccountName>New Account...</AccountName><br />
    <Incomming>Please enter your POP3 server address.</Incomming><br />
    <Outgoing>Please Enter your STMP server address.</Outgoing><br />
    <IncommingPort>110</IncommingPort><br />
  </Account>

Sometimes i get the error, there is no row at position 0 and sometimes i do not get it. Any help would be nice, ive spent a while reading some books and the msdn but i cannot figure out what i am doing wrong.

thanks
xarx

Re: XML Dataset and Removing Rows...

John Fisher4-Nov-02 8:08

John Fisher

4-Nov-02 8:08

I don't know what's causing your problem. However, you might get the piece of informtion you need by changing "p.Message" to "p.ToString()". When dealing with Exceptions, the ToString() method gives much more information than the Message property.

John

Re: XML Dataset and Removing Rows...

hammackj4-Nov-02 13:35

hammackj

4-Nov-02 13:35

Mr Clifton told me what i was doing wrong, I was not writing the deleted row back to the xml file. Now everything is fine. Thank you for replying =)

C# Database question

Anonymous2-Nov-02 14:57

Anonymous

2-Nov-02 14:57

Do C# database classes have anything like the old ADO had:

while(!pDs->EOF())
{
/////
pDs->MoveNext();
}

I have noticed that we have tables, rows, andcolumns, but i am
curious as to how maintain a dataset between pages in a case
such as a multipage search engine?

Re: C# Database question

ian mariano2-Nov-02 15:25

ian mariano

2-Nov-02 15:25

If you use a SqlDataReader, this may help:

//  assumes cmd is a System.Data.SqlCommand object
SqlDataReader r = cmd.ExecuteReader(/* omitted for brevity  */);

while(r.Read())
{
   //  do something with r, like Console.WriteLine(r["field"].Value)
}

As far as part 2, you could use a page Cache of the dataset, and a Repeater control you modify to do the "pagination" The Microsoft .NET Pet Shop 2.0[^] has an example of one of those to paginate data.

-- ian

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano - http://www.ian-space.com/

Re: C# Database question

Munti4-Nov-02 5:48

Munti

4-Nov-02 5:48

You could also do that with OleDbConnection like this:

OleDbDataReader myReader = myCom.ExecuteReader();
while(myReader.Read()){
// do your thing here with myReader
}

Børge Warvik

process id?

imran_rafique2-Nov-02 14:21

imran_rafique

2-Nov-02 14:21

please see this code i want to start a process.After successful
starting i want to get its id for further processing.For that
purpose most of my processes are setup files (of some software like installers)
most of the processes execute this code successfuly but when i start
a process for example setup file of yahoo messanger installer or VCD Cutter installer
and some other software they all raise an exception(InvalidOperationException)
at last line although the process started successfully and its window appears
,and started process has its existance.

i want to get its id only(in last line of this code ).
my question is
why it raise an exception although started process has its existance?
i think its id is changed.am i right ?
if yes how to trace it id?
or it might be possible that the main process i start also start some other process and
exit itself. if thats true how to trace these processes?

int idpro;
tmpProcess = new Process();
tmpProcess.Exited += new EventHandler(this.ProcessExited);
tmpProcess.EnableRaisingEvents=true;
tmpProcess.StartInfo.FileName=strProcName;
try
{
 tmpProcess.Start();
 while(! tmpProcess.Responding)System.Windows.Forms.Application.DoEvents();
}
catch
{
//MessageBox.Show("The Process: " + strSelectedProcess + " cannot start !");
}
idpro=tmpProcess.Id;

r00d0034@yahoo.com

Stephane Rodriguez.2-Nov-02 19:15

2-Nov-02 19:15

Your process needs to have a main window handle for .Responding to work well. (.Responding will send it a timeout message and expects an answer).

I guess you may avoid any exception raise if you would do that instead :
if (tmpProcess!=null && tmpProcess.MainWindowHandle!=IntPtr.Zero) idpro = tmpProcess.Id;

PS : .Responding does not work on W9X systems under certain circumstances, as said in the doc.

Back to real work : D-27.

imran_rafique3-Nov-02 15:20

imran_rafique

3-Nov-02 15:20

first of let me tell you i am using xp.
GOOD CHECK but that check avoid me to get id of an existing window like yahoo messanger because its window exist after calling start but its id dont.
is it possible that tmpProcess is not null and its id also dont exist.
please tell a little bit about this check
tmpProcess.MainWindowHandle!=IntPtr.Zero
what that IntPtr.Zero is?

r00d0034@yahoo.com

Stephane Rodriguez.3-Nov-02 18:49

3-Nov-02 18:49

imran_rafique wrote:
GOOD CHECK but that check avoid me to get id of an existing window like yahoo messanger because its window exist after calling start but its id dont.
is it possible that tmpProcess is not null and its id also dont exist.

I don't like the way the .NET Process class gets a process ID, it assumes several things internally, and depending on the process, they may well be wrong.
I would definitely use interop to get that process ID, it should not be that hard.

imran_rafique wrote:
tmpProcess.MainWindowHandle!=IntPtr.Zero

that's aimed to check if the mainwindowhandle is not null. IntPtr has an enum inside, IntPtr.Zero is one of the values of that enum.

Back to real work : D-27.

imran_rafique4-Nov-02 15:00

imran_rafique

4-Nov-02 15:00

whats interop?

r00d0034@yahoo.com

Stephane Rodriguez.4-Nov-02 18:59

4-Nov-02 18:59

[DllImport("kernel32", CharSet=CharSet.Auto)]
static public extern int GetCurrentProcessId();

Back to real work : D-26.

HttpRequest

kavehdr2-Nov-02 11:30

2-Nov-02 11:30

Hi, I am playing with the HttpRequest class to try to make something work. I found that it appears, everytime you user the GetResponse() from the WebRequest, you have to initialize the object again, to get proper response in the pages that are authenticated. Is this normal, should it be like this?

WebRequest request = (HttpWebRequest) WebRequest.Create(URI);
/... do the network credentials here
request.GetResponse();
/... do something else

//this line has to be here to use GetResponse() again.
request = (HttpWebRequest) WebRequest.Create(URI);
/....
request.GetResponse();

K.D.

Re: HttpRequest

Vasudevan Deepak Kumar5-Nov-02 3:55

Vasudevan Deepak Kumar

5-Nov-02 3:55

Hey kavehdr,

YOu may feel free to check out http://www.aspalliance.com. It has some beautiful code in HttpRequest and a wrapper for FtpWebRequest too.

Perhaps that should help you in your queries.

I think Google Search of

aspalliance httpwebrequest

should bring you the pages that you are looking for. Sorry that, I do not remember the exact URL looking for at AspAlliance. But the abovespecified search pattern lands up in AspAlliance site first.

deepak

Deepak Kumar Vasudevan
http://deepak.portland.co.uk/

Assembly

kavehdr2-Nov-02 7:46

2-Nov-02 7:46

Hi, is it possible to write assembly inside C# code; similiar to what we were able to do in borland c++, using the asm keyword

Thanks

K.D.

Daniel Turini2-Nov-02 8:04

Daniel Turini

2-Nov-02 8:04

No, but you can use pointers and some other "low-level" operations with the "unsafe" keyword

lazy isn't my middle name.. its my first.. people just keep calling me Mel cause that's what they put on my drivers license. - Mel Feik

kavehdr2-Nov-02 8:13

2-Nov-02 8:13

So there is basically no way to open EXE files and read and write to them at binary level?

K.D.

John Fisher2-Nov-02 9:22

John Fisher

2-Nov-02 9:22

Reading and writing to files of any format can certainly be in C#. I'm not sure how that relates to using assembly instructions from inside C#, though.

John

ian mariano2-Nov-02 9:59

ian mariano

2-Nov-02 9:59

You trying to patch .exes?

If you really want to use .NET and assembly, use c++ 7 and __asm, but you'll need to do extra stuff if its within Managed Code.

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano

http://www.ian-space.com/

kavehdr2-Nov-02 11:32

2-Nov-02 11:32

Yeah kinda. Things like changing the exe header...etc.
No way to do in c#?

K.D.

John Fisher2-Nov-02 13:29

John Fisher

2-Nov-02 13:29

Maybe I'm showing my ignorance, but what special need is there for __asm when all you're doing is changing the contents of a file?

C# provides easy file access, just check the System.IO.FileStream and other classes within the System.IO namespace.

If you are trying to do more complicated things than merely reading and writing to the file (like trying to monkey with an already executing program), then you can try using the System.Runtime.Interop namespace to access most/all of the Windows APIs. If you still can't get there, then you can create a C++ dll to do the specific work you need, and call that from C#.

John