Re: To Heath (we talked about this subject before) - C# Discussion Boards

Re: Assembly - from Unmanaged

25-Mar-04 9:35

Don't take this the wrong way, but I really hate agism. I - and a handful of others blessed with the skills of good development - were programming circles around some of our University profs. I was one of 3 go-to guys when I was still in high school in a town of over 20,000 back then. In this field, actually development skills have little to do with age. Again, don't take it the wrong way, but it's just a pet pieve of mine. I've experienced a lot of unnecessary hardships because of it from upper management taking credit or passing credit to others for what I did soley (and I don't mean just giving credit to the team, which I could handle - I mean actually saying that they personally did it all).

I also don't limit myself to development (not coding, which I use to refer to those that blindly write code without really knowing what they're doing). I love photography and people - including my father, a professional photographyer - say I have an eye for it. I also learned WAY MORE about feminine hygeine in high school since most of my friends were girls (as you can probably guess, I wasn't a big fan of athletes).

Microsoft MVP, Visual C#
My Articles

Jeremy Kimball25-Mar-04 9:46

Jeremy Kimball

25-Mar-04 9:46

Don't take *this* the wrong way, but you need to lighten up Smile | :)

I was being extremely sarcastic in saying I'm older than you. (born on 5/10/77, which makes me a whopping year older than you). I was and still am in the same boat you're in now - problems dealing with "old-school" developers who don't trust your judgement, even when it's obviously right.

I had the same situation with the whole female thing in high school...it's an interesting experience trying to explain the female ovulation cycle to your girlfriend Smile | :)

To Heath (we talked about this subject before)

profoundwhispers24-Mar-04 9:10

profoundwhispers

24-Mar-04 9:10

public sealed class Singleton<br />
{<br />
    static readonly Singleton instance=new Singleton();<br />
<br />
    // Explicit static constructor to tell C# compiler<br />
    // not to mark type as beforefieldinit<br />
    static Singleton()<br />
    {<br />
    }<br />
<br />
    Singleton()<br />
    {<br />
    }<br />
<br />
    public static Singleton GetInstance()<br />
    {<br />
        return instance;<br />
    }<br />
}

That was from this[^] article.

Maybe you can answer this question:

Is there an explicit need there for the private constructor to avoid initialization? If we remove it completely, will .NET supply a default public parameterless constructor?

Sammy

"A good friend, is like a good book: the inside is better than the cover..."

Tom Larsen24-Mar-04 9:14

Tom Larsen

24-Mar-04 9:14

The point of making a constructor private/protected is so that someone using the object via the API can't create an instance on their own. This is very handy if you want to make an object with singleton behavior.

The only way you get the instance (the only instance) is using GetInstance. Doing it this way, there is no other way create the object. If you leave a construtor publicly exposed then it cirumvents the code you put in place to enforce the singleton behavior.

profoundwhispers24-Mar-04 9:32

profoundwhispers

24-Mar-04 9:32

Thank you that was very clarifying.

Sammy

"A good friend, is like a good book: the inside is better than the cover..."

Heath Stewart24-Mar-04 9:15

24-Mar-04 9:15

If you remove the private default constructor, yes, the compiler will provide one.

Also, this isn't the best singleton pattern to use. The one I posted earlier was. It uses a double-check locking approach which eliminates a couple race conditions that may occur.

This has been discussed in the past in this forum so if you want to know more, try searching for "singleton" or something for the C# forum.

Microsoft MVP, Visual C#
My Articles

profoundwhispers24-Mar-04 9:31

profoundwhispers

24-Mar-04 9:31

Well, what I'm doing right now is, I'm providing the binary deserialization mechanism in the static constructor, since I only need to load the settings from the file once in the lifetime of the program. Then, I'm providing a Save instance method so that I could save multiple times, which is needed whenever the settings dialog is opened and closed with Ok button.

If there is nothing wrong with this in your opinion, then don't post an answer; otherwise, please comment.

Thanks!

Sammy

"A good friend, is like a good book: the inside is better than the cover..."

Heath Stewart24-Mar-04 9:39

24-Mar-04 9:39

There's nothing wrong with it, but what I was referring to in the previous post could result in your settings being loaded more than once. Now, this probably wouldn't be a problem, but locking your resources will gaurantee that it wouldn't.

I'm not trying to down-play your approach, only present different ideas. It's you're implementation - do what you want. Smile | :)

Typically in a singleton you provide static methods and properties and hide instance details from other classes. For instance, you could also have your Save method as static and it gets the private Instance property (or uses your GetInstance method) and saves the data. For the caller then, it's as simple as doing MySettings.Save.

Again, just some things to think about. Your approach would work fine in most cases (only may become a problem with multiple AppDomains in a single process, which may not apply).

Microsoft MVP, Visual C#
My Articles

Windows Media Player

antoine@orchus-tech24-Mar-04 7:36

antoine@orchus-tech

24-Mar-04 7:36

Hi
I am using VS 2003 with the latest windoze media player.

I want to hide a video in a dll.
Then I want the media player to access it. How do I do that?

Thanks!

Antoine

This by our hands that dream,
"I shall find a way or make one!"

Heath Stewart24-Mar-04 8:35

24-Mar-04 8:35

You can't, not without implementing your own native pluggable protocol handler for windows (like that which handles http(s), ms-help, its, res, etc.). Windows Media Player uses monikers to bind to streams and there is not - at this time - a plugglable protocol handler for streaming embedded resources.

Also, embedded a video in an assembly is extremely wasteful. You'll increase the load times of the assembly incredibly. Just distribute it as a separate file and point the URL property of WMP to the file when you need to play it.

Microsoft MVP, Visual C#
My Articles

antoine@orchus-tech24-Mar-04 9:38

antoine@orchus-tech

24-Mar-04 9:38

Yeah,

OK. thanks for the answer. didn't thought about the loss of loading time.
Do you know of a way to keep the videos secure? Digital Rights Managment
seems a way to go -is it??? Wink | ;)

Cheers

Antoine

This by our hands that dream,
"I shall find a way or make one!"

Heath Stewart24-Mar-04 9:42

24-Mar-04 9:42

Yes, DRM would be something to look into.

Beside, if you think storing the file as an embedded resource (or even in the .rsrc section of the PE/COFF executable itself) would keep it secure, you'd be sorely surprised. ildasm.exe, for example, can easily extract anything in an assembly. One could throw together a simple .NET app to do this as well. Resources in native DLLs can easily be extracted, too (though writing the code for it is a big harder, but plenty of apps - including Visual Studio - can make quick and easy work of that by just loading the .rsrc section and providing extraction capabilities).

If you did want to embed it stil, you'd have to extract it anyway in order for WMP to play it. At that point someone could also mess with it.

DRM is really about your only protection, if it is really that necessary.

Microsoft MVP, Visual C#
My Articles

antoine@orchus-tech24-Mar-04 9:58

antoine@orchus-tech

24-Mar-04 9:58

Thanks for the input! Ok So the request forms are all sent out.
I just I wont need to shell out money by the windows. Smile | :)

Cheers

Antoine

This by our hands that dream,
"I shall find a way or make one!"

How to enumerate an enum.

Stephane Rodriguez.24-Mar-04 19:03

Stephane Rodriguez.

24-Mar-04 19:03

Lookup MSDN and Google with "res://"

Anonymous24-Mar-04 6:56

Anonymous

24-Mar-04 6:56

Can anyone tell me how to get a list of data types.

I'm trying to fill a combobox with data types, such as string, int, long, etc., and am wondering how I can enumerate whatever enum that holds those.

And in asking that question, a better one would be how do you enumerate any enum and pull out a string representation of the members.

Something like this... maybe...

public enum Colors
{ red, green, blue }

foreach(string color in Colors)
{
...color.ToString();
}

Re: How to enumerate an enum.

CStiefeling24-Mar-04 8:16

CStiefeling

24-Mar-04 8:16

Have a look at the Enum class (system namespace) -- GetNames and GetValues should help.

--Chris

Re: How to enumerate an enum.

T Manjaly24-Mar-04 11:49

T Manjaly

24-Mar-04 11:49

See this sample... it talks exactly what you want :

http://dotnetspider.com/Technology/KBPages/69.aspx

Sleepy | :zzz:

---------------------------------------------------------------------- Cry | :((

T Manjaly

C# Tutorials and samples : http://www.dotnetspider.com

axWebBrowser DocumentComplete

Jasper4C#24-Mar-04 6:47

Jasper4C#

24-Mar-04 6:47

Hi !

I need to know when my axWebBrowser finished the navigation to the web page. I hooked to .DoumentComplete event but it turns out that this event happens more than 1 time !?? (Why ?)

So - how I can tell when the web page is completly loaded ??

"I have not failed.
I've just found 10,000 ways that won't work."
- Thomas Alva Edison (1847-1931)

Heath Stewart24-Mar-04 8:40

24-Mar-04 8:40

See http://support.microsoft.com/support/kb/articles/q180/3/66.asp[^] for an explanation and a workaround.

Basically, DocumentComplete is fired multiple times when a page contains references to multiple documents (i.e., frames). The easiest way is to is to see if the pDisp field of the DWebBrowserEvents2_DocumentCompleteEvent is the same reference as your AxWebBrowser instance. That'll signify that the top-level frame document has been loaded.

Microsoft MVP, Visual C#
My Articles

Dave Kreskowiak24-Mar-04 8:42

Dave Kreskowiak

24-Mar-04 8:42

In a page with Frames, there are multiple web pages being used to render one visible page. There is a frames page that describes the layout of the view panes, then there is a seperate page for each of those panes. DocumentComplete will fire for every one of those pages that is downloaded, not just the frames page.

You can use the uRL property of the eventargs to compare to the URL you sent the browser to. If the page has frames, the last URL to be returned will be the one you originally sent the browser to:

    Private Sub AxWebBrowser1_DocumentComplete( _
            ByVal sender As Object, _
            ByVal e As AxSHDocVw.DWebBrowserEvents2_DocumentCompleteEvent) _
            Handles AxWebBrowser1.DocumentComplete
 
        If AxWebBrowser1.LocationURL = e.uRL Then
            MsgBox("Document Complete!")
        Else
            Debug.WriteLine("DocumentComplete received for URL: " & e.uRL)
        End If
    End Sub

RageInTheMachine9532

Heath Stewart24-Mar-04 9:03

24-Mar-04 9:03

You copied and pasted VB.NET code from the MS KB into a C# forum? You should be punished. Poke tongue | ;-P

Microsoft MVP, Visual C#
My Articles

Jeremy Kimball24-Mar-04 9:27

Jeremy Kimball

24-Mar-04 9:27

"Get the whips and chains! Bind the heathen!"

Smile | :)

Dave Kreskowiak24-Mar-04 9:28

Dave Kreskowiak

24-Mar-04 9:28

Yes and No...

Yes, I pasted VB code into the C# Forum. AAAAAAAhhhhhh! My mistake! D'Oh! | :doh:

I should be flogged.

It's not the exact code from the MS KB. I found that the code in the KB was for VB6 and didn't translate very well to VB.NET. The .Object property wouldn't compile. So I changed it to use the URL properties instead. It can be fooled by a redirection in the original page, but that's shouldn't be too much of a concern.

RageInTheMachine9532

Heath Stewart24-Mar-04 9:29