CRC-16 Convert to C vb.Net - C# Discussion Boards

Re: Algorithm Question - Urgent Help Needed

J4amieC9-Nov-05 0:19

9-Nov-05 0:19

A few thoughts:

if i=0 and m=011 how do you determine, when parsing, that a value of 0 is 'i' or the start of 'm'? The answer is that you need to have a defined way of making each value unique. A pointer for you would be to base your 0's and 1's from morse code, where this uniqueness is enforced - also morse (in case you dont know) is made up of dots and dashes - very fitting with your 1's and 0's

Ok, onto parsing the string - take a look at StringTokenizer's - there are at least two articles here on CP about the principle - and it is basically what you want - in (unwritten) code;

StringTokenizer st = new StringTokenizer("011010101");<br />
string convertedString = "";<br />
while(st.HasMoreTokens)<br />
{<br />
    char nextChar = st.NextToken();<br />
    convertedString += nextChar;<br />
}

Re: Algorithm Question - Urgent Help Needed

HymanRoth9-Nov-05 0:43

HymanRoth

9-Nov-05 0:43

This problem is potentially non-trivial.

There are two things your forgot to specify. The first is whether there can be more than one correct parsing for each string. For example, your string parsed to "mike", but (with the right additional codes) it could also have parsed to pratically any other alphanumeric output. This is key in determining when and how the algorithm should terminate. The second problem is one of scope. How long is the input string and how big is the table of values? The way the algorithm will work is to search through the space of ALL POSSIBLE parsings and output those that complete. Clearly, the bigger your input string and lookup table get, the more the chances of seeing a 'combinatorial explosion'.

If you answer these questions, I will help you write the algorithm. Please let me know if you are comfortable with embedded recursion, or your pefer iterative processes. The former is much more elegant, but with big inputs could create memory problems.

-- modified at 6:45 Wednesday 9th November, 2005

Re: Algorithm Question - Urgent Help Needed

allenmpcx9-Nov-05 0:47

allenmpcx

9-Nov-05 0:47

I prefer embedded recursion. There can be more than one correct parsing for each string, and for this example, the table is limited to the alphabet (lower-case and upper-case) and also '\n', ' ', and '\t'.

I love to program!

Re: Algorithm Question - Urgent Help Needed

leppie9-Nov-05 6:58

leppie

9-Nov-05 6:58

Search for Huffman compression/encoding, there's alot more to it than you think.

^{xacc.ide-0.1-rc2 released! Download and screenshots}

Source File: c:\windows\microsoft.net\framework\v1.1.4322\Config\machine.config Line: 198

israfel8-Nov-05 23:02

israfel

8-Nov-05 23:02

Hi Everyone,
If anyone could help me out i'd really appreciate it because this problem is really holding back the project. I'm getting the dreaded

Source File: c:\windows\microsoft.net\framework\v1.1.4322\Config\machine.config Line: 198 problem

which i'm pretty sure one or two of you might be familiar with seeing as there are threads on it all over the internet. The reason i'm posting this is because i've tried every solution on the threads i've seen and none work. Restarting the computer, adding a blank space to my web config file, turning off indexing service (it wasn't on in the first place), replacing the .DLL's with ones from their main build, clearing out the VS Cache and rebuilding. None of which worked, still the same error when i try to run my web project which leaves me at a virtual standstill as everything else i need to develop is dependent on this.

If anyone has a solution which is either a working variation of one of the above or a different way you found to get your web project back up and running i'd very much appreciate if you'd share it as i can't afford the time being wasted trying to find out whats wrong right now.

Cheers

Use of Datagrid for non database app

ratinahat0018-Nov-05 22:41

ratinahat001

8-Nov-05 22:41

Can anyone tell me please if its possible to bind a datagrid to an array of
objects (defined by me) so that when i update the contents of the array, the
data grid updates its display.

Any tips would be greatly appreciated.

Greg.

Re: Use of Datagrid for non database app

Rody van Sambeek9-Nov-05 13:07

Rody van Sambeek

9-Nov-05 13:07

Yes this is possible when you let the dataclass inherit van a CollectionBase to make a collection. Check this article for more information:
http://www.codeproject.com/csharp/collection1.asp

Rody van Sambeek

Rody van Sambeek

CRC-16 Convert to C vb.Net

RichardBerry8-Nov-05 22:22

RichardBerry

8-Nov-05 22:22

Hi

Please could someone help me to convert the following to Visual Basic.. or alternatively post a table driven version

It is a CRC16 algorithm using the polynomial (x16 + x15 + x2 + 1) used for very short strings.

I think (not sure) a test string of "123456789" should generate a hex checksum of: BD3B

Tks

Richard

static unsigned BitsSet (unsigned char ch)
{
unsigned n;
n = 0;
while (ch)
{
n += (ch & 1);
ch >>= 1;
}
return(n);
}

unsigned CRCof (const char *message, unsigned len)
{
unsigned i;
unsigned crc;
unsigned char k;

crc = 0;
for (i=0; i<len; i++)
{
k = (unsigned char)(message[i]) ^ crc;
crc = (crc / 256) ^ (k*128) ^(k*64);
if ((BitsSet(k) & 1) != 0)
crc ^= 0xC001;
}
return(crc);
}

Retreive file list from remote server using ftp - Error 226 - Urgent help required

SheenSylesh8-Nov-05 22:03

SheenSylesh

8-Nov-05 22:03

Hi all,

I'm using ftp with the command "NLST *.*\r\n". After I send this command I get a reply:
"226 Transfer complete". I just want to get the file list, the weird thing is that
Sometimes the command works and sometimes doesnt.

The commands: USER, PASS, CWD and PASV work FINE before "NLST" command.

Any idea why?

thanx

-- modified at 6:29 Wednesday 9th November, 2005

How to Bind ComboBox1 with DataSet1 ?

majidbhutta8-Nov-05 21:54

majidbhutta

8-Nov-05 21:54

I want to bind a ComboBox with a DataSet by supplying a datasource and

also want to specify ComboBox.valueMember and ComboBox.DisplayMember in a

windows form in C#. What i m trying is below the piece of code but i m

not getting the required result;

ComboBox1.DataSource = DataSet1;
ComboBox1.DisplayMember = "StudentName";
ComboBox1.ValueMember = "StudentID";

How to Bind ComboBox1 with DataSet1 ? Please correct the above code

snippt.

Re: How to Bind ComboBox1 with DataSet1 ?

Susan Hernandez9-Nov-05 14:42

Susan Hernandez

9-Nov-05 14:42

Try this snippet. I think you simply didn't bind to the Table, rather than the data set.

// Set up the DataSet
DataSet ds = new DataSet();
			
// Set up the Data Table
DataTable t = new DataTable("Students");
t.Columns.Add("StudentID", typeof(int));
t.Columns.Add("StudentName", typeof(string));

ds.Tables.Add(t);

// Fake Data
for(int i = 0; i < 5; i++)
{
	DataRow r = t.NewRow();
	r["StudentID"] = i;
	r["StudentName"] = "Test Student " + i.ToString();
	t.Rows.Add(r);
}

// Bind to the Combo Box
comboBox1.DataSource = ds.Tables[0];  
// NOTE that my data source is the table, not the dataset

comboBox1.ValueMember = "StudentID";
comboBox1.DisplayMember = "StudentName";

Access the selected value:

private void comboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{
	MessageBox.Show(comboBox1.SelectedValue.ToString());
}

Re: How to Bind ComboBox1 with DataSet1 ?

n10sive10-Nov-05 12:04

n10sive

10-Nov-05 12:04

you need to add more qualification.

ie.
ComboBox1.DataSource = DataSet1.Table

or
ComboBox1.DataSource = DataSet1;
ComboBox1.DisplayMember = "Table.StudentName";
ComboBox1.ValueMember = "Table.StudentID";

Cheers

Parent Form Child Form Problem

ekynox8-Nov-05 20:37

ekynox

8-Nov-05 20:37

G'day folks,

I am stuck on a form design problem which I just cant seem to find any solution. I have an application (Parent Form) which requires another window (child form) to be open in a modeless mode (using Show()) and whose TopMost property is set to true. My problem becomes that if I switch applications in the taskbar, say from my application to Outlook (running in maximized mode), the child form still stays on top of Outlook. This is because the child form is set to TOPMOST being true.

One solution I had was to use the Deactivate and Activated event handlers for the parent form. In the Deactivate event handler I setup so that the child form would become invisible and in Activate Handler the child form would become visible. I didnt realise that once the parent form become active it will then make the child form visible thereby the child form become the active form thus firing the Deactivate handler for the parent form. Therefore getting stuck in an infinite loop of child form appearing and disappearing.

There has to be a solution since when the find window is open in notepad and another application is active the find window from notepad doesnt dominate.

Can anyone point out what mistake I am making, I realise this has to be a very elementary mistake.

I would really appreciate any feedback.

thanks
Vee

Re: Parent Form Child Form Problem

hga_gi8-Nov-05 23:05

hga_gi

8-Nov-05 23:05

Don't use the TopMost property which is 'absolute', but the Owner property which describes a 'local order' in your application's forms set.

Tchimbaw

Re: Parent Form Child Form Problem

ekynox8-Nov-05 23:36

ekynox

8-Nov-05 23:36

thanks for the tip. You have just saved me from having a sleepless night Smile | :)

how to add module in c#.net?

sarayumadhavan8-Nov-05 20:00

sarayumadhavan

8-Nov-05 20:00

hi
how to add module in c#.net? There is no option in the menu project-> add module in c#.net which we have in vb.net.

sarayu

Re: how to add module in c#.net?

FriendlyFiend8-Nov-05 22:50

FriendlyFiend

8-Nov-05 22:50

why do you need this, a class with static methods has equivalent functionality

Removing Cookies and Temp Internet Files

sonicsqwirl8-Nov-05 19:43

sonicsqwirl

8-Nov-05 19:43

I am trying to programatically remove cookies and temp internet files. I have found examples of how to change the Expire of cookies via Web Dev. But the Request.Cookies() doesn't work in Windows Dev.

My program is simple,

<br />
static void Main(string[] args)<br />
		{<br />
			LaunchWindows();<br />
			//ClearCache();<br />
		}<br />
private static void LaunchWindows()<br />
		{<br />
System.Diagnostics.Process.Start("IExplore.exe","http://lbprdapps:88/autosys/login"); <br />
}<br />
private static void ClearCache()<br />
{<br />
// Clear the cookies and temp internet files here<br />
}<br />

Here is the VB equivalency in Web Dev. that I want to accomplish.

<br />
Dim i As Integer<br />
Dim cookieName As String<br />
Dim limit As Integer = Request.Cookies.Count - 1<br />
For i = 0 To limit<br />
   aCookie = Request.Cookies(i)<br />
   aCookie.Expires = DateTime.Now.AddDays(-1)<br />
   Response.Cookies.Add(aCookie)<br />
Next<br />

Any help would be appreciated.

TIA,
Scott

Error.....Net Remoting

deep78-Nov-05 19:02

deep7

8-Nov-05 19:02

Hi all,
i'm woking on a project which uses .Net remoting architecture.
Previously i wasn't gettin this error, but now sometimes i get his error, and i cant figure out why it comes..and how to fix it.
Please if any one knows about it, do tell what to do..

Error: Timedout expired. The timeout period elapsd prior to obtaining a connection from the pool. This may have occured because all the pooled connections weer in use and max pool size was reached..

Thanx

Calling a C# COM Object from VC++ 6.0

E6AD8-Nov-05 17:16

E6AD

8-Nov-05 17:16