C# Discussion Boards - CodeProject

Smitha Nishant30-Nov-02 23:54

30-Nov-02 23:54

Hello,

I am trying to do an image editing app.
It requires opening and displaying an image and then selecting a portion of the image for crop. I also want to rotate the image.

(1)How will I implement "area selection" [click and drag to mark an area] for an image ?
(2)Which will be the best control to display the image, for edit operations?

Thanks,
Tweety

It's easy to sit there and say you'd like to have more money. And I guess that's what I like about it. It's easy. Just sitting there, rocking back and forth, wanting that money.

Re: Image edit

Christian Graus1-Dec-02 16:22

Christian Graus

1-Dec-02 16:22

Tweety wrote:
How will I implement "area selection" [click and drag to mark an area] for an image ?

Draw the image, store the co-ordinates you've dragged, and draw them onto the window ( not onto the image ), so they are lost with every refresh and do not affect the image.

Tweety wrote:
Which will be the best control to display the image, for edit operations?

Just whack it right onto your window.

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Re: Image edit

Smitha Nishant2-Dec-02 18:01

Smitha Nishant

2-Dec-02 18:01

Thanks CG for the help.

Christian Graus wrote:
Just whack it right onto your window.

Isn't there any image control that will scroll and show the original image ?

Tweety.

It's easy to sit there and say you'd like to have more money. And I guess that's what I like about it. It's easy. Just sitting there, rocking back and forth, wanting that money.

sscanf equivalent in C#?

roybrew30-Nov-02 16:18

roybrew

30-Nov-02 16:18

Does anyone know of a sscanf (Old C-runtime function) equivalent in C#?

Regards,

Roy

_____________
Roy H. Berger
roybrew@att.net

Re: sscanf equivalent in C#?

David Stone30-Nov-02 18:22

David Stone

30-Nov-02 18:22

Use the System.Convert class. There's a bunch of stuff in there that will let you convert from one data type to another.

I don't know whether it's just the light but I swear the database server gives me dirty looks everytime I wander past.
-Chris Maunder

Microsoft has reinvented the wheel, this time they made it round.
-Peterchen on VS.NET

Re: sscanf equivalent in C#?

Nick Parker30-Nov-02 18:37

Nick Parker

30-Nov-02 18:37

roybrew wrote:
Does anyone know of a sscanf (Old C-runtime function) equivalent in C#?

As David said you can use the Convert class however sscanf provided more of a parsing technique than what you will probably find with Convert. You may wish to look into the RegEx (regular expressions) class as that's where the power will come from (;P). Here is a quick article to read up on if you are new to regular expressions.
C# Regular Expressions [^]

Nick Parker

Re: sscanf equivalent in C#?

David Stone30-Nov-02 19:13

David Stone

30-Nov-02 19:13

Nick Parker wrote:
sscanf provided more of a parsing technique than what you will probably find with Convert

Forgive me for not brushing up on my C libraries.;P

Re: sscanf equivalent in C#?

roybrew1-Dec-02 5:24

roybrew

1-Dec-02 5:24

I'll look at RegEx. The parsing is what I am looking for. I've looked at Convert. Maybe a combination of both ?? Basically, I'm parsing comma delimited data (text, numeric, date, etc.).

Thanks for the suggestions.

Regards,

Roy

_____________
Roy H. Berger
roybrew@att.net

Re: sscanf equivalent in C#?

Shaun Wilde2-Dec-02 4:24

Shaun Wilde

2-Dec-02 4:24

try the Split method on string to break it up into little strings

Stupidity dies.
The end of future offspring.
Evolution wins.
- A Darwin Awards Haiku

Net Send

Bugoy29-Nov-02 19:03

Bugoy

29-Nov-02 19:03

Does anybody know how to do "NET SEND" using C#?

Re: Net Send

Tomtomm29-Nov-02 23:39

Tomtomm

29-Nov-02 23:39

[DllImport("Netapi32.dll", CharSet=CharSet.Auto)]<br />
private static extern int NetMessageBufferSend(string servername,string<br />
msgname,string fromname,string buf,int buflen);<br />
<br />
string msg = "My text";<br />
NetMessageBufferSend(null,"remotePC",null,msg,msg.Length*2+2);

Hope this helps !

Tomtom

About threads and forms...

GriffonRL29-Nov-02 6:16

GriffonRL

29-Nov-02 6:16

Hello,

I wrote a program who is not UI dependent. I have all my program logic in a class and I raise some events for any potential frontend.
I can then create a console application or a Windows form application using the same program logic.
The frontend just run a thread using the run() function of my main class (UI independent) which do all the job.
This main class also creates internally several threads performing various tasks in parallel. Since all this threads are just pure computation I have no problems.
But I recently wanted to create forms in some of these internal threads running in parallel and I have been unsuccessful for far Frown | :(

What happens is that forms get created but are not responsive at all and the internal threads get stuck. How can I create these forms and make them run independently in each thread ?

Here is schema:

Frontend (Console or Form, main thread)
|
|
Main class (running in a thread)
| | | | |
| | | | |
Child threads (computation)
x x x x x <-- child threads can not work with forms
x x x x x <-- how to call functions in those forms ?
Child threads forms

Any idea ?

R. LOPES
Just programmer.

Re: About threads and forms...

leppie29-Nov-02 9:09

leppie

29-Nov-02 9:09

You must invoke methods from other threads, instead of calling them directly.

DBHelper - SQL Stored Procedure Wrapper & Typed DataSet Generator for .NET

Re: About threads and forms...

GriffonRL29-Nov-02 9:36

GriffonRL

29-Nov-02 9:36

Hello,

I understood I have to use invoke from threads to call methods in controls.
But what about creating forms from threads ?

Thanks,

R. LOPES
Just programmer.

Re: About threads and forms...

leppie29-Nov-02 9:51

leppie

29-Nov-02 9:51

GriffonRL wrote:
But what about creating forms from threads ?

???? Eek! | :eek:

What are you trying to do? I would keep my whole UI in one thread (the main one preferably).

DBHelper - SQL Stored Procedure Wrapper & Typed DataSet Generator for .NET

Re: About threads and forms...

GriffonRL29-Nov-02 10:01

GriffonRL

29-Nov-02 10:01

Hi,

My goal is to have several forms running independently. Each form has its own thread doing a specific computation.
One example could be to have several forms embedding the webbrowser control and automatically crawling a different website. All will run in parrallel.

Any idea ?

R. LOPES
Just programmer.

Re: About threads and forms...

leppie29-Nov-02 10:20

leppie

29-Nov-02 10:20

GriffonRL wrote:
Any idea ?

I would STILL keep all the controls on one thread, but make them child form (usercontrols rather). I suggest you use something like the Magic Library's DockingManager as the hosting windows can easily move outside the form area or hidden.

DBHelper - SQL Stored Procedure Wrapper & Typed DataSet Generator for .NET

Is it possible to use webbrowser control outside a form ?

GriffonRL29-Nov-02 6:00

GriffonRL

29-Nov-02 6:00

Hello,

I would like to know if it is possible to use the webbrowser control just to navigate a webpage and then traverse its DOM, without creating a form and even in a console application ?

Thanks,

R. LOPES
Just programmer.

Re: Is it possible to use webbrowser control outside a form ?

Stephane Rodriguez.29-Nov-02 6:17

Stephane Rodriguez.

29-Nov-02 6:17

Lookup a sample called WalkAll in MSDN.

Re: Is it possible to use webbrowser control outside a form ?

GriffonRL29-Nov-02 6:45

GriffonRL

29-Nov-02 6:45

Hello Stephane,

Ok but WalkAll uses only the MSHTML component. I'm trying to use the WebBrowser control because it adds a lot of navigation stuff I would like not to take care of.

Thanks,

R. LOPES
Just programmer.

Re: Is it possible to use webbrowser control outside a form ?

Stephane Rodriguez.29-Nov-02 6:48

Stephane Rodriguez.

29-Nov-02 6:48

UI --> iexplore.exe | web ocx
no UI --> walkall

Both have the DOM and the IWebBrowser interface (shdocvw) to play with.

Re: Is it possible to use webbrowser control outside a form ?

GriffonRL29-Nov-02 6:53

GriffonRL

29-Nov-02 6:53

Hello,

Ok then. So what is the DLL I'm supposed to use ?
Shdoccvw or mshtml ? Or both ?
And what happens without any UI when a NewWindow event is trigerred ?

Thanks,

R. LOPES
Just programmer.

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