Re: getting the visible pixel-colors - C# Discussion Boards

Eric Gunnerson (msft)12-Sep-02 10:21

Eric Gunnerson (msft)

12-Sep-02 10:21

I think you'll have to use P/Invoke to call directly into the Win32 API to do this.

Here's a class I wrote that should get you started; it does screenshots now.

http://www.gotdotnet.com/userarea/keywordsrch.aspx?keyword=win32window

One more thought - GDI+ supports alpha channel blending, which lets you do transparency. I don't know if it works for windows over the desktop, but it's worth exploring. You'll find it in the System.Drawing namespace.

Rüpel12-Sep-02 20:15

Rüpel

12-Sep-02 20:15

i will look at your class in a minute. thx. Smile | :)

i know about the alpha-blending and i'm using it. that's why i need the background-pixels. i want to know which color to use for text in the transparent area. when the background is dark, i use a light color, when it is red i use ... you see?

:wq

Rüpel12-Sep-02 21:15

Rüpel

12-Sep-02 21:15

yep. it works. great man! Smile | :)

so GetDesktopWindow is the magic function. hmm. i always thought it takes a picture of the background-image of the desktop...but luckily i was wrong and it really takes a screenshot Smile | :)

btw: what das msft mean? Eek! | :eek:

:wq

Using the WindowsXP FaxService from C#

James T. Johnson12-Sep-02 22:44

James T. Johnson

12-Sep-02 22:44

Rüpel wrote:
what does msft mean?

Microsoft, if I remember correctly Eric is one of the higher ups of the C# team.

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

Alexandru Serban11-Sep-02 21:21

Alexandru Serban

11-Sep-02 21:21

Hello everybody !

I want to use the WindowsXP FaxService COM API in my solution. I`m using Visual Studio .NET
I added a reference to the FaxService TypeLibrary in the project and the generated NameSpace is FAXCOMEXLib.

Then I wrote the following code:

try<br />
{<br />
   FAXCOMEXLib.FaxServerClass FaxServer=new FAXCOMEXLib.FaxServerClass(); // OK<br />
   FaxServer.Connect(""); // OK<br />
		<br />
   FAXCOMEXLib.FaxFolders FaxFolders=FaxServer.Folders; // NOT OK<br />
<br />
}<br />
catch(Exception ex)<br />
{<br />
   MessageBox.Show(ex.Message);<br />
}<br />

After creating the FaxServer object and connecting it to the local FaxService, the Properties that return an object (like Folders,InboundRouting,LoggingOptions) are not valid.
There is a {System.InvalidCastException} in the Value of the Autos section in the debugger. Why?

Thank you !

Anyone know of a good C# magazine?

Rocky Moore11-Sep-02 21:16

Rocky Moore

11-Sep-02 21:16

Hmmm? Something completely dedicated to C#/.NET/ASP.NET? Tired of hearing people battle languages or all the things Microsoft did wrong, just a good regularly updated source of information C#.

Rocky Moore

Christian Graus11-Sep-02 21:33

Christian Graus

11-Sep-02 21:33

MSDN is a pretty good mag - I just resubscribed myself.

Christian

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

Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002

Rickard Andersson²⁰12-Sep-02 3:44

Rickard Andersson²⁰

12-Sep-02 3:44

If I I didn't lived in sweden and lived in US instead I would subscribe to that magazine!

It's too expensive to import to sweden! Frown | :(

Rickard Andersson@Suza Computing
C# and C++ programmer from SWEDEN!
UIN: 50302279
E-Mail: nikado@pc.nu
Speciality: I love C#, ASP.NET and C++!

Rocky Moore12-Sep-02 17:55

Rocky Moore

12-Sep-02 17:55

Christian Graus wrote:
MSDN is a pretty good mag - I just resubscribed myself.

Yeah, it is pretty good for articles and is one of the most worn Smile | :)

The only other one I read with any regularity is Visual Studio magazine but it is falling quickly. They keep pushing VB.NET. I guess most of their readers must be VB'ers but I don't care to ever read an article written in VB, I left the DIM statement over 20 years ago and don't care to go back Smile | :)

It surprises me that some company has not jumped on it yet. With .NET/C# the possibilities of coding have increased in such leaps that it put the fun back in programming. That is not to mention how you have to wrap you mind around a completely new programming model. Reminds me of when I jumped from C programming in DOS to C++ and Windows 3.0, totally different worlds.

I would love to find a magazine or eZine that similar to the old Compute! Magazine or even Byte for that matter just all consumed in .NET and C#. You know articles that help you code not argue compatibilities and capabilities. I am already sold on C#, no turning, I just want exciting articles on coding and best practices of coding in this new world.. There seems to be a large number of programmers involved in C#/.NET, well maybe the media will pick up more on it.

Just take a look here at CP. The C# forum runs usually 15%-40% of the volume of the C++ forum which CP has mostly been a C++ site. It’s catching on…

[stepping down from soapbox]

Thanks for the suggestion.

Rocky Moore

Christian Graus12-Sep-02 18:52

Christian Graus

12-Sep-02 18:52

Visual Studio mag WAS VB Developer mag, they merged with their failed C++ mag, which failed because it moved entirely to C# without changing the name. I gave up on it long ago.

Christian

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

During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002

Rocky Moore12-Sep-02 19:45

Rocky Moore

12-Sep-02 19:45

Christian Graus wrote:
Visual Studio mag WAS VB Developer mag, they merged with their failed C++ mag, which failed because it moved entirely to C# without changing the name. I gave up on it long ago.

And now Visual Studio Magazine is completely failing.. Have you noticed how thin they are Wink | ;)

I personally would be willing to pay a subscription to a decent magazine on the topic with an organized advertising section (I still like looking at the ads).

Rocky Moore

Break program flow

D Shen11-Sep-02 8:55

D Shen

11-Sep-02 8:55

Hi,

My application will collect different parameters from user input. Once the "Execute" button is pressed, the parameters will be passed to related methods for exection. I try to figure out how to stop the program flow (not close the application but ask input for missing parameters)if I find some parameters missing (something like Exit() in VB) Can someone please tell me how to do this? Thanks!! OMG | :OMG:

Nnamdi Onyeyiri11-Sep-02 9:07

Nnamdi Onyeyiri

11-Sep-02 9:07

get the seperatly called messages to throw an exception if a parameter they need is missing, then use the try/catch loop in Execute to catch the exceptions, and do something about it. Smile | :)

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

D Shen12-Sep-02 3:06

D Shen

12-Sep-02 3:06

Thank you. Since I am new to C#, can you please show me how to throw an exception and catch it? Thanks!

Nnamdi Onyeyiri13-Sep-02 5:20

Nnamdi Onyeyiri

13-Sep-02 5:20

there are different types of exceptions in the framework, and you can derive your own, but here is a simple way do throw and catch an exception.

// to thow an exception
throw new Exception("The error text here.");

// catch an exception
try
{
   // This method throws an exception [as above] if something is wrong
   SomeFunction();
}
catch
{
  MessageBox("There was an error with your input!");
}

hope that helps Smile | :)

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

Paul Riley11-Sep-02 13:16

Paul Riley

11-Sep-02 13:16

Application.Exit()
?

Paul

David Stone12-Sep-02 3:55

David Stone

12-Sep-02 3:55

He said:
D Shen wrote:
not close the application but ask input for missing parameters

;-PNnamdi told him how to do it.

David Stone

But Clinton wasn't a predictable, boring, aging, lying, eloquent, maintainer-of-the-status-quo. He was a predictable, boring-but-trying-to-look-hip, aging-and-fat-but-seemingly-oblivious-to-it, lying-but-in-sadly-blatant-ways, not-eloquent-but-trying-to-make-up-for-it-by-talking-even-more, bringer-in-of-scary-and-potentially-dangerous-new-policies. And there was also Al Gore. It just wasn't *right*.

Shog⁹