C# Discussion Boards - CodeProject

Re: Object Serialization with an ArrayList

Spyder_Snyper7-Aug-07 4:39

7-Aug-07 4:39

So you have provided me with some fantastic help. Although I'm once again at a loss.

Now that I have a Serialized Stream, how do I save it to a file?

Re: Object Serialization with an ArrayList

Hessam Jalali7-Aug-07 6:43

Hessam Jalali

7-Aug-07 6:43

if you don't need your Stream after serialization process you can simply use FileStream instead of MemoryStream and directly save it to the disk.

but if you need your stream so you can save it using StreamWriter Class

<code>

        void SaveToDisk(string path, Stream stream)
        {
            stream.Seek(0, SeekOrigin.Begin); //put the pointer at first
            using (StreamWriter sw = new StreamWriter(path))
            using (StreamReader sr = new StreamReader(stream))
            {
                sw.Write(sr.ReadToEnd());
                sw.Flush();
            }
        }

</code>

if you had problem with StreamWriter and Reader you can use BinaryWriter and Reader (a little bit harder to use but I don't think you need them)

good Luck my Friend Smile | :)

Cannot generate SSPI context error

xbiplav6-Aug-07 5:17

xbiplav

6-Aug-07 5:17

I have developed a small database software in .Net 2.0 which has backend as Sql Server Express2005.Both of the server and client are running Windows XP. My client successfully detects the server but when connecting to the server, it displays the error message "Cannot
generate SSPI context".

I have also searched the internet but couldnot find any good solutions.
Could you people have any solution for this terrible error?

Help appreciated in both VB.Net and C#.

X

Re: Cannot generate SSPI context error

snorkie6-Aug-07 11:49

snorkie

6-Aug-07 11:49

Probably should post this in the SQL / ADO / ADO.NET section... If you go over to that forum and search for SSPI, you might even get some answers. The 5th search down should have the answer you're looking for.

Hogan

Re: Cannot generate SSPI context error

mav.northwind7-Aug-07 1:18

mav.northwind

7-Aug-07 1:18

I usually get this error when our domain controller cannot be reached while trying to access a SQLServer DB.
Don't know what to do about it, though...

Regards,
mav

--
Black holes are the places where God divided by 0...

File Encoding

Sean_B6-Aug-07 4:22

Sean_B

6-Aug-07 4:22

Hello,

I'm hoping someone can help me determine how a file is encoded when I read it in c#.

I'm reading in thousands of files that stretch over a couple of decades, and the files seem to keep changing their encryption.

the files are comma delimited and they have a header record.

I'm using the column names in the header record to create a column mapping for SqlBulkCopy, this is because over the years column names have changed or new columns have been added.

My program stops if an unrecognised column name is found and then I can check it and enter it into a mapping table.

However I'm occasionally getting strange characters in the column headings. I initially got around this problem by determing the encoding (using the peice of code at the end of the message) however I still seem to be coming across files where I can't tell what the encoding is and I'm getting strange characters (mainly when a "£" sign is not recognised).

I'm reading the file using this

using (StreamReader sr = new StreamReader(sourceFile, Encoding(sourceFile), true)

Can anyone help with this, I would be happy to replace unrecgognised characters if possible.

--------determine the type of encoding----
public static System.Text.Encoding Encoding(string sourceFile)
{
System.IO.FileStream file = null;
System.Text.Encoding enc = System.Text.Encoding.ASCII;

try
{
file = new System.IO.FileStream(sourceFile,
FileMode.Open, FileAccess.Read, FileShare.Read);

if (file.CanSeek)
{
byte[] bom = new byte[4]; // Get the byte-order mark, if there is one
file.Read(bom, 0, 4);
if ((bom[0] == 0xef && bom[1] == 0xbb && bom[2] == 0xbf) || // utf-8
(bom[0] == 0xff && bom[1] == 0xfe) || // ucs-2le, ucs-4le, and ucs-16le
(bom[0] == 0xfe && bom[1] == 0xff) || // utf-16 and ucs-2
(bom[0] == 0 && bom[1] == 0 && bom[2] == 0xfe && bom[3] == 0xff)) // ucs-4
{
enc = System.Text.Encoding.Unicode;
}
else
{
enc = System.Text.Encoding.ASCII;
}
// Now reposition the file cursor back to the start of the file
file.Seek(0, System.IO.SeekOrigin.Begin);
}
else
{
enc = System.Text.Encoding.ASCII;
}

// Close the file: never forget this step!
file.Close();
return enc;
}
--------determine the type of encoding end----

Sean

Re: File Encoding

Luc Pattyn6-Aug-07 4:37

Luc Pattyn

6-Aug-07 4:37

Hi,

I trust recent files with a BOM (byte order mask) pose no problems ?

I expect problems to exist on older files that used ASCII/ANSI or some special "code page"
to accomodate whatever special requirement existed at the time (such as the pound sign.

Seems to me you should try to classify your files in a few groups, by symptom,
and then solve it for each group individually; I dont expect there to be a ready-made
solution since what you encounter probably is ad-hoc solution attempts to small encoding
problems.

For files without BOM I often find it useful to build a histogram for the byte values,
then print out the counts that are not zero and correspond to special values (say
verything above 0x7E).

Hope this helps.

Luc Pattyn [Forum Guidelines] [My Articles]

this weeks tips:
- make Visual display line numbers: Tools/Options/TextEditor/AllLanguages/General
- show exceptions with ToString() to see all information
- before you ask a question here, search CodeProject, then Google

Re: File Encoding

Sean_B6-Aug-07 5:26

Sean_B

6-Aug-07 5:26

Thanks for this, I'll try addressing it by groups of files.

Sean

PNG compression?

Mad_Mike6-Aug-07 3:52

Mad_Mike

6-Aug-07 3:52

Hi all,

I really hope there is a simple and good solution for my problem. I'm opening a .jpg image (640 x 480 pixels / 96 x 96 dpi / 24 bit depth / 30kb) using Image.FromFile(); After that i'm creating a thumbnail using
GetThumbnailImage(298, 160, dummyCallBack, IntPtr.Zero);
thumbNailImg.save(location, ImageFormat.Png);

This results in a .png image (298 x 168 pixels / 178 x 134 dpi / 32 bit depth / 90kb). But as result i want a smaller (compressed) png image with the following attributes: 298 x 168 pixels, 71dpi, 24 bits depth. How can this be done? I've been looking all over the internet but didn't find any good solution.

Anyone who can help me out? Thanks in advance!

Re: PNG compression? [modified]

PhilDanger6-Aug-07 4:11

PhilDanger

6-Aug-07 4:11

You can ~~set~~ get these things through various Image properties -- HorizontalResolution, VerticalResolution, PixelFormat.

These may take a few attempts to get it the way you want, but I'm sure with a bit of effort you'll be able to do it.

Edit: SetResolution to change the Horizontal and VerticalResolution, PixelFormat is set during the constructor for the bitmap.

-- modified at 10:30 Monday 6th August, 2007

Re: PNG compression?

Mad_Mike6-Aug-07 4:14

Mad_Mike

6-Aug-07 4:14

Those attributes are read-only....

Re: PNG compression?

PhilDanger6-Aug-07 4:29

PhilDanger

6-Aug-07 4:29

Resolutions can be changed through the SetResolution method. PixelFormat must be set in the constructor.

Re: PNG compression?

Mad_Mike6-Aug-07 5:04

Mad_Mike

6-Aug-07 5:04

Thnx!

I've changed the way i created the png image to the one you mentioned. Now i can create an empty Bitmap with the requered attributes en 'paste' te original into it.

excel

TAREQ F ABUZUHRI6-Aug-07 3:10

TAREQ F ABUZUHRI

6-Aug-07 3:10

how can read information within excel file from C# application

Palestine

Re: excel

Nisar Inamdar6-Aug-07 3:13

Nisar Inamdar

6-Aug-07 3:13

What u mean.....?
Describe little more...
So i can help u?

Nisar Inamdar.
Always for u...

Re: excel

TAREQ F ABUZUHRI6-Aug-07 4:03

TAREQ F ABUZUHRI

6-Aug-07 4:03

see this excel file
http://paltareq.brinkster.net/down/complete_apps_rep.xls

in my c# application i want to make for loop to read each cell in the file ?

Palestine

Re: excel

Vasudevan Deepak Kumar6-Aug-07 3:23

Vasudevan Deepak Kumar

6-Aug-07 3:23

Excel ODBC Driver http://www.codeproject.com/database/excel_odbc.asp[^]

Vasudevan Deepak Kumar
Personal Homepage
Tech Gossips

Re: excel

Giorgi Dalakishvili6-Aug-07 3:25

Giorgi Dalakishvili

6-Aug-07 3:25

You can use the OleDb Managed Data Provider to read an Excel Spreadsheet using ADO.NET and C#

#region signature
my articles
#endregion

Re: excel

Bhavesh Bagadiya6-Aug-07 4:26

Bhavesh Bagadiya

6-Aug-07 4:26

You can use InterOp service provided by Microsoft using Excel namespace.

namespace for Excel is,

Microsoft.Office.Interop.Excel

Re: excel

\laddie6-Aug-07 4:29

\laddie

6-Aug-07 4:29

Hi Bhavesh,

Just a gentle suggestion.
This solution needs that you either assumes Office to be installed in the machine or you have to distubute the office libraries along with the Apps.

Please find my last post for this question it sould provide a better and faster solution.

laddie

Re: excel

\laddie6-Aug-07 4:27

\laddie

6-Aug-07 4:27

TAREQ

Try this

using System.Data.OleDb;
using System.Data;
.
.

//I am not sure giving url in the filename will work.Please check it

OleDbConnection oleConnection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+fileName+@";Extended Properties=""Excel 8.0;HDR=YES""");

oleConenction.Open();

OleDbCommand cmd= new OleDbCommand("select * from [Sheet1$]",oleConnection);
OleDbDataReader read = cmd.ExecuteReader();

while(read.Read())
{
Console.WriteLine(read[0]+......);
}

Please let me know if it helps

Laddie
}

Add variable to object reference

Rick van Woudenberg6-Aug-07 2:30

Rick van Woudenberg

6-Aug-07 2:30

Dear all,

If I create a new reference to an object, I would like to add a variable to that newly create reference. Let's say :

Foo foo = new Foo();

Now, everythime the code runs, I would like a variable added to foo, let's say :

First time it is called :

Foo foo1 = new Foo();

Second :

Foo foo2 = new Foo();

Is there an easy way of doing this ?

Cheers,

Re: Add variable to object reference

Luc Pattyn6-Aug-07 2:52

Luc Pattyn

6-Aug-07 2:52

No.
What is the actual problem, why would you want this ?

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Re: Add variable to object reference

Vasudevan Deepak Kumar6-Aug-07 3:24

Vasudevan Deepak Kumar

6-Aug-07 3:24

foo1 and foo2 are separate instances.

Vasudevan Deepak Kumar
Personal Homepage
Tech Gossips

Re: Add variable to object reference

\laddie6-Aug-07 3:33

\laddie

6-Aug-07 3:33

Hi ,

I too wonder of the exact situation you would require to do that.If you can tell that we should be able to help you ourt more.

However calling the new on any object will be creating a new instance itself

eg:

Foo f;

for(int i=0;i<10;i++)
{
f= new Foo();
}

will create 10 new instances rather than 1 even though you are using the same variable name.

laddie

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