Re: Stream writing html - C# Discussion Boards

WideChar

yyf17-Sep-04 3:14

yyf

17-Sep-04 3:14

Hi,

How to convert string to WideChars when calling a legacy dll from .Net?

Thanks.

Re: WideChar

Heath Stewart17-Sep-04 6:33

Heath Stewart

17-Sep-04 6:33

You don't - strings are wide characters (Unicode) by default in .NET. You actually have to convert to ANSI when calling native functions on Windows (as opposed to Windows NT).

We have convered this countless times in the past, so I urge you both now and in the future to search first for previous similar questions. You can search this forum by clicking "Search comments" above.

For an introduction to marshaling strings with Platform Invoke (P/Invoke), read Marshaling Strings[^]. Basically, when you use the DllImportAttribute to P/Invoke native DLL entry points, or define a structure for use with a native function using the StructLayoutAttribute, you set the CharSet field that both have to CharSet.Ansi (default for P/Invoke) to call only ANSI functions (where native strings are declared as char*), CharSet.Unicode to call only Unicode functions (where native strings are declared as wchar_t*, almost always the case for OLE/COM), or CharSet.Auto when you want to call ANSI functions in Windows (i.e., Windows 9x/ME) and Unicode functions in Windows NT (i.e., Windows NT 4, Windows 2000, Windows XP, Windows 2003, and "Longhorn", plus all future Windows platforms). Windows only supports ANSI (although there is a Unicode layer, but that's an extra install) and Windows NT typically supports both but it's better to use Unicode because it allows for a much larger character set and you don't have to mess with codepages.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles]

Filefield postback woes

Vodstok17-Sep-04 3:08

Vodstok

17-Sep-04 3:08

I have recently created a form that gives the user the option of filling out certain information in either text fields, or as file attachments, or a combination of both.

The problem i am runninginto, is that if the user clicks the browse button and selects a file, then hits any of the other controls that do a postback, the selected file is lost.

I have tried using this.filefield.EnableViewState = true to see if that would keep, but it doesnt. i also have not been able to progromatically assign a value or a PostedFile.Filename. the page errors out and says that they are not "settable" (gotta love "msenglish")

if i could grab the information and pass it to a hidden field, or allow the viewstate to hold it, that would be great. My only other recourse is to make it so that selecting files to upload is the LAST thing that can be done before submission, but that is a pain in and of itself, and doesnt do doodily squat for the user if they have to go back and redo something before submission. they would have to start any files they wanted to upload all over again...

Yes, I am the highly suggestable type.

Re: Filefield postback woes

sreejith ss nair17-Sep-04 3:40

sreejith ss nair

17-Sep-04 3:40

hi,

You can sumbit this question in our Asp.net discuson.

i can suggest one solution of this.
Try to set the value of AutoPostBack property to false.

**************************
S r e e j i t h N a i r
**************************

Re: Filefield postback woes

Vodstok17-Sep-04 4:36

Vodstok

17-Sep-04 4:36

thanks, forgot which forum i was in.. reposting in ASP.net

Yes, I am the highly suggestable type.

Stream writing html

Mikke_x17-Sep-04 2:50

Mikke_x

17-Sep-04 2:50

Hi all! I have a wierd problem and I can´t understand why it happens.

I have a couple of html pages that I read from and write to.
When I read and write I use FileStream.ReadByte() and FileStream.WriteByte(). The problem I have is that when I view the file in IE after it is done, IE can not recognise the my swedish characters ( å,ä,ö ).

What really bothers me is that if I take the source of the page via IE and copy paste it into a textfile and give it the extension html there are no problems at all. There is absolutely no differences between the files that work and the ones that does not work, the content of the pages are the same, but still IE can read one and not the other.. D'Oh! | :doh:

There have to be some differences in some part of the not visible content of the files, but how do I resolve the problem? I need to save the files, and in my current implementation I would like to use stream.WriteByte() but I would also like to keep the swedish characters. Please advice..

/ Mikke

Re: Stream writing html

Steven Campbell17-Sep-04 4:33

Steven Campbell

17-Sep-04 4:33

It is usually inappropriate to write text (html) at the byte level. This is because modern unicode strings do not have a simple 1 byte = 1 character mapping.

What is probably happening is that the file you are reading from is in one text encoding (e.g. UTF8), and the file you are writing to is in another (e.g. ASCII).

Just read and write strings, and you should be fine. It may help to educate yourself on text encodings first though.

One of the better articles on this subject is from Joel on Software.

my blog

Re: Stream writing html

Heath Stewart17-Sep-04 6:53

Heath Stewart

17-Sep-04 6:53

Steven's right, but what you need to do is actually quite easy.

Wrap your FileStream (or whatever Stream derivative you're using) in a StreamReader or StreamWriter, which makes reading and writing text much easier. You can specify the encoding (like

Encoding.Unicode, since you're probably dealing with Unicode characters on the 'net, or UTF8 which is most common (a multi-byte character set, or MBCS)) and with the <code>StreamReader

you can set a parameter in the constructor that attempts to detect the encoding by detecting a byte-order mark (BOM).

For example:

using (FileStream file = File.Open("somefile.html", FileMode.Open))
{
  string line = null;
  using (StreamReader reader = new StreamReader(file, Encoding.UTF8, true))
  {
    // It's bad to use reader.ReadToEnd - you might not have enough memory
    line = reader.ReadLine();
    // Do something with the 'line'
  }
}

The using blocks make sure the streams are closed (i.e., the native file handles are released - very important or your performance is hampered, or - worse yet - you have memory leaks).

You should really read about the Encoding class in the .NET Framework SDK. You could still read and write bytes but you must understand that ANSI is a single-byte character set, and may use different code pages. ASCII characters use only 7 bits in the byte (the first 128 values). The last 128 values can be different depending on the codepage (local characters, or defined for particular systems). UTF8 can handle ASCII characters, but those latter characters actually tell the decoder to use 2 bytes to read the character, thus supporting Unicode as well. This is a great encoding to use on legacy systems, especially if you're not sure what a text file will contain (although a legacy decore might have problems). Unicode comes in many flavors, and you can read more on the web if you try a google search or click "Search comments" above for previous discussions we've had about this.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles]

Re: Stream writing html

Mikke_x17-Sep-04 7:14

Mikke_x

17-Sep-04 7:14

Hi! Thanks alot! Both to Heath and Steven!
Will try this first thing monday morning!

The Joel on Software text gave som intresting, and fun!, reading.

/ Mikke

posting data to another url using webclient

Abraham Durairaj17-Sep-04 0:31

Abraham Durairaj

17-Sep-04 0:31

Hi,

Im writing a component for posting data to a webserver.

http://www.domainname.com/fire/incoming.asp?user=xxxx&pass=xxxx&amount

I tried using HttpWebrequest & Webclient to post data but it is returning an error

if i paste the url in the browser it is working properly

The code goes here
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

string User = "test3";
string Pass = "test3";

string amount = Server.UrlEncode(TextBox2.Text);
string MobileNumber = "91"+TextBox1.Text;

string postData = ("login="+User);
postData += ("&pass="+Pass);
postData += ("&amount="+amount);

string uriString = "http://www.domainname.com/fire/incoming.asp";

WebClient myWebClient = new WebClient();
myWebClient.Headers.Add("Content-Type","application/x-www-form-urlencoded");

byte[] byteArray = Encoding.ASCII.GetBytes(postData);
byte[] responseArray = myWebClient.UploadData(uriString,"POST",byteArray);

lblStatus.Text = Encoding.ASCII.GetString(responseArray);

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Can someone help .....

Thanks in advance

Abraham

MaskEdit

jzb17-Sep-04 0:09

jzb

17-Sep-04 0:09

I want to do a maskedit control that it like powerbuilder or delphi's maskedit
control.

Re: MaskEdit

Heath Stewart17-Sep-04 6:37

Heath Stewart

17-Sep-04 6:37

Great...what's your question?

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles]

Graphical programming

Member 62427317-Sep-04 0:06

Member 624273

17-Sep-04 0:06

Hi all,

I would like to program in c# a graphical design tool like ms visio. I need the functionalities of component inserting, deleting, resizing, moving, component connecting and so on. Someone knows sample codes or tutorials?

Thx

Re: Graphical programming

Colin Angus Mackay17-Sep-04 1:10

Colin Angus Mackay

17-Sep-04 1:10

I would say that is more of an OO thing than an algorithmic thing.

For example, you have two classes called DrawingSurface and Component.

DrawingSurface has a collection of Components

To Insert you instantiate a component (Component theComponent = new Component()) and add it to the DrawingSurface (DrawingSurface.Add(theComponent);)

To Delete to remove the component from the DrawingSurface (DrawingSurface.Remove(theComponent);)

To Resize you would have properties on the component like Width and Height. You might trigger an event on the setters of these properties that the DrawingSurface would handle to redraw the diagram.

To Move you would have position properties on the component like X and Y. And again in the setters you would probably fire off an event that the drawing surface uses to redraw the display.

And so on and so forth.

"If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

Not getting the response you want from a question asked in an online forum: How to Ask Questions the Smart Way!

custom progressbar, problem updating it.

misterbear16-Sep-04 23:50

misterbear

16-Sep-04 23:50

I've tried to create a custom progressbar to display while I'm doing some intensive work. I also want to update a string of what is currently going on, like an installer tells the user what file is currently being copied, and so on...
So, I have a form that I display and then call methods like

<br />
MyProgressForm.setProgressText(string)<br />
MyProgressForm.setProgress(int)<br />

but the GUI components (a label for the text and a custom-painted control for the progress) won't get updated, I guess because there is too much work going on...

So my question is, how do I force these to be updated?
What is the best way to solve this?

thankful for some help, I can't seem to figure it out ...

Re: custom progressbar, problem updating it.

Stefan Troschuetz17-Sep-04 2:47

Stefan Troschuetz

17-Sep-04 2:47

Calling the Update method of your ProgressBar after changing its Value or Text should solve the problem.

www.troschuetz.de

Re: custom progressbar, problem updating it.

Tim Kohler17-Sep-04 9:49

Tim Kohler

17-Sep-04 9:49

You should be doing the lengthy processor intensive work in a thread seperate from the main gui thread. Start a worker thread and do your lengthy work there. Update the progress bar's values from the worker thread. The main window thread will then keep your bar painted properly.

correl function for c#

tradingsharp16-Sep-04 22:56

tradingsharp

16-Sep-04 22:56

Hi

I am searching for a correl function like the one i can use in excel with =CORREL(A1:A10;B1:B10).

Nothing complicated I will just know the correlation of two arrays.

I have googled but wasn't successful. Maybe somebody have a hint where to search.

Thanks

Re: correl function for c#

leppie16-Sep-04 23:46

leppie

16-Sep-04 23:46

Just search for general statistics formulas IIRC

std deviation = ((n1 - avg )^2 + (n2 - avg )^2 + ... )^1/2

or something like that Smile | :)

^{top secret
Download xacc-ide 0.0.3 now!
See some screenshots}

Reg. Posting data to other url

Abraham Durairaj16-Sep-04 18:50

Abraham Durairaj

16-Sep-04 18:50

Im posting some data to this URL.

Can someone tell me where i can post data to this url like this.

string uriString = "http://domainname.com/incoming.asp";

WebClient myWebClient = new WebClient();
myWebClient.Headers.Add("Content-Type","application/x-www-form-urlencoded");

(or )

do we need to post only to

string uriString = "http://domainname.com/";

WebClient myWebClient = new WebClient();
myWebClient.Headers.Add("Content-Type","application/x-www-form-urlencoded");

Can anyone help me how to go about this?

Abraham

How can I add , update , delete a row

skywen16-Sep-04 16:51

skywen

16-Sep-04 16:51

in DataGrid of WinForm Use C#?

thanks!!

Re: How can I add , update , delete a row

sreejith ss nair16-Sep-04 23:59

sreejith ss nair

16-Sep-04 23:59

hi,

Check this site for your queary.

www.datagridgirl.com

Section head : article

**************************
S r e e j i t h N a i r
**************************

Re: How can I add , update , delete a row

Kodanda Pani17-Sep-04 21:06

Kodanda Pani

17-Sep-04 21:06

Hi skywen,

When you are using Datagrid control on winforms by default it allows you to add, delete , update rows during the runtime. If you are using a Data grid webserver control you need to use footer template to create this functionality.

Thanks
SGS

How do i force a control to only exist in the component tray?

FocusedWolf16-Sep-04 15:59

FocusedWolf

16-Sep-04 15:59

One suggestion i found was to extend System.ComponentModel.Component

My problem is that thing doesnt have paint or other necessary visual functions. Any other ways?

...My situation is a control that is like a tooltip not dedication to the form but considers the desktop as it's parent... what it boils down to is i want to make it a component tray restricted control, but give it a custom UI editor so someone can view changes to the control.

Server application

qigong516-Sep-04 13:37

qigong5

16-Sep-04 13:37

Hi all,

I'm hoping someone can point me in the right direction.

I would like to write a server application that takes data from various elements within a network. These are UNIX based systems which basically will be spitting alarming information at m at a billion miles an hour. Consequently, I'm establish communications with the sending devices. I only want to receive the information they are throwing at me. I don't need to be concerned with the format of the data.

Has anyone suggestions on how best to implement a server type application to recieve the data from 10+ uniques device elements without having to establish a link first. All devices output on the same port number as well to throw in another problem.

Any advice, suggestions would be most appreciated.

Thanks,

Aaron

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