Threads vs. Async calls (delegate)? - C# Discussion Boards

Re: How to use "win32_find_data" in C# or VB.net?

31-Aug-02 2:14

Hi
You will need to define 2 structures in C# first namely, FILETIME and WIN32_FIND_DATA. As:

struct FILETIME { 
    int dwLowDateTime; 
    int dwHighDateTime; 
}

struct WIN32_FIND_DATA {
  int dwFileAttributes; 
  FILETIME ftCreationTime; 
  FILETIME ftLastAccessTime; 
  FILETIME ftLastWriteTime; 
  int nFileSizeHigh; 
  int nFileSizeLow; 
  int dwReserved0; 
  int dwReserved1; 
  string cFileName; //mite need marshalling, TCHAR size = MAX_PATH???
  string cAlternateFileName; //mite need marshalling, TCHAR size = 14
}

[DllImport("kernel32.dll")]
static extern IntPtr FindFirstFile( IntPtr lpfilename, ref WIN32_FIND_DATA findfiledata);

[DllImport("kernel32.dll")]
static extern IntPtr FindClose( IntPtr pff);

public static WIN32_FIND_DATA FindFile(string filename)
{
  WIN32_FIND_DATA fd;
  IntPtr pff = FindFirstFile(Marshal.StringToHGlobalAuto(filename), ref fd);
  if (ppf == IntPtr.Zero) throw new FileNotFoundException();
  FindClose(ppf);
  return fd;
}

Thats should do it, didnt check. Perhaps the TCHAR in the structs, but this should set u well on your way. Obviously, you can Add the other FindFile functions as well.

Maybe there is something in .Net doing the same already???

Smile | :)

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leppie31-Aug-02 2:22

Re: How to use "win32_find_data" in C# or VB.net?

31-Aug-02 2:22

HAHA

There is an example on MSDN doing exactly what you need. Pretty much the same as above. Smile | :)

Look here, direct MSDN link, sorry dont have weblink, but should be easy to find.

FindFile Sample [C#][^]

Enjoy Smile | :)

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leppie31-Aug-02 4:24

Threads vs. Async calls (delegate)?

31-Aug-02 4:24

And finally the .NET way....jeez i'm bored today Smile | :)

Directory.GetFileSystemEntries Method

Returns the names of all files and subdirectories in the specified directory.

[Visual Basic] Overloads Public Shared Function GetFileSystemEntries(String) As String()
[C#] public static string[] GetFileSystemEntries(string);

Returns an array of file system entries matching the specified search criteria.

[Visual Basic] Overloads Public Shared Function GetFileSystemEntries(String, String) As String()
[C#] public static string[] GetFileSystemEntries(string, string);

Smile | :)

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TigerNinja_30-Aug-02 7:38

TigerNinja_

30-Aug-02 7:38

Lets say I wanted to have a GUI application go out and get multiple stock quotes from many different sites. However, I would like each process to be independent of the other, because one website might not respond well. For example, I don't want the first process to hold up the others. I also will need some kind of response (write quote to GUI) from that process

Suppose I have a method GetQuote, and I want it to return the quote.

string GetQuote(string companySymbol, Uri siteToGetTheQuoteFrom)

Note: Thread does not necessarily mean the .NET object I am trying to use it in a general generic sense.

Thread1 -> GetQuote("ABC", http://www.nasdaq.com)
Thread2 -> GetQuote("MSFT", http://msnmoney.com)
Thread3 -> GetQuote("ACN", http://fool.com)

What approach would I take, using Threads or Async calls via delegates ?

Thanks in advance

Soliant | email

"The whole of science is nothing more than a refinement of everyday thinking." -Albert E.

Re: Threads vs. Async calls (delegate)?

leppie30-Aug-02 7:45

Re: Threads vs. Async calls (delegate)?

30-Aug-02 7:45

Hi there

I saw a user code sample of a web spider on GotDotNet.com. It was written (very cleverly indeed) by one of MS's people (soz cant remember name now).

In the example he uses a managed ThreadPool and fires the requests from there. I would say this looks like your best bet.

Hope you find it, else i'll try get it Smile | :)

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TigerNinja_30-Aug-02 8:57

TigerNinja_

30-Aug-02 8:57

leppie wrote:
Hope you find it, else i'll try get it

Found it, http://www.gotdotnet.com/userfiles/toub/SpiderNet.zip[^] now I am going to review the app.
Thanks again.

Soliant | email

"The whole of science is nothing more than a refinement of everyday thinking." -Albert E.

Re: Threads vs. Async calls (delegate)?

James T. Johnson30-Aug-02 9:03

James T. Johnson

30-Aug-02 9:03

leppie wrote:
In the example he uses a managed ThreadPool and fires the requests from there. I would say this looks like your best bet.

Async delegate calls use the ThreadPool to perform their operations so it would essentially be the same Wink | ;)

James
"And we are all men; apart from the females." - Colin Davies

CultureInfo could not be serialized by WebService Parameter,

Chris Richner30-Aug-02 2:14

Chris Richner

30-Aug-02 2:14

I've got a client application which defines a class that has a CultureInfo Porperty, now if i try to pass this class as Parameter to my Webservice the engine says "System.Globalization.CultureInfo cannot be serialized because it does not have a default public constructor.
".
But CultureInfo is marked as [Serializable], where's the problem and how to fix it ?

.:Greets from Jerry Maguire:.

Audio Output

Nnamdi Onyeyiri30-Aug-02 1:42

30-Aug-02 1:42

I was just wondering how i would go about doing this.

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"All programmers are playwrights and all computers are lousy actors."

Michael Mac30-Aug-02 2:10

Michael Mac

30-Aug-02 2:10

Here is a link to nBASS 0.9.2 library written in C# which wraps BASS library

43 68 65 65 72 73 2c
4d 69 63 68 61 65 6c

leppie30-Aug-02 2:48

30-Aug-02 2:48

Thx Micheal

Have a look at the examples.

BTW im busy working the WMA dll into it, so you should expect it soon Smile | :)

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Nnamdi Onyeyiri30-Aug-02 3:03

30-Aug-02 3:03

thanks for the link, but what i was really interested in was knowing where i can find a resource [if its possible] on actually outputting the sound, not using a third party library. Smile | :)

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"All programmers are playwrights and all computers are lousy actors."

leppie30-Aug-02 3:50

30-Aug-02 3:50

U mean like a source on decoding the audio? u can perhaps look at winmm.dll and maybe do something from there... Unsure | :~

or DirectSound (the VB wrapper) or u can wait for DX9 , which will work alot like nBASS (I actually had a look a few days ago at beta 2's managed functions and its pretty similar).

For most things you will be needing a 3rd party library, just like YOU are using MS .NET as a 3rd party library for applications, etc. If u get what i am saying. Smile | :)

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Blinking in GDI+

Majid Shahabfar30-Aug-02 1:37

Majid Shahabfar

30-Aug-02 1:37

Are there any blinking possibility in GDI+?

Nnamdi Onyeyiri30-Aug-02 1:42

30-Aug-02 1:42

if you want to blink, i think your gonna have to use a timer, to redraw every so often, switching between on and off Smile | :)

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"All programmers are playwrights and all computers are lousy actors."

Majid Shahabfar30-Aug-02 7:29

Majid Shahabfar

30-Aug-02 7:29

Thank you.
I know using timer for blinking, but I wanna know that has GDI+ this possibility without using timer?
I don't wanna use timer. I'm looking for another method.
If you remember you could use blinking in MS-DOS without timer.

Maciej Pirog30-Aug-02 7:48

Maciej Pirog

30-Aug-02 7:48

In Windows, GDI+ can draw on a surface (window, bitmap etc). But a window cannot redraw itself (to draw another blinking state) after some time without using timer!

You can also create a c# control that will redraw itself with timer. It won't do any mess in your app, and will work great! That depends on what kind of blibking element do you need.

Ñ There is only one MP Ð

Nnamdi Onyeyiri30-Aug-02 10:15

30-Aug-02 10:15

Majid Shahabfar wrote:
If you remember you could use blinking in MS-DOS without timer.

Eek! | :eek:

bit before my time mate, infact, 3.1 is before my time too Poke tongue | ;-P

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"All programmers are playwrights and all computers are lousy actors."