C# Discussion Boards - CodeProject

Stefan Troschuetz2-Jun-04 8:08

2-Jun-04 8:08

I once experienced the same thing. After long experiments I discovered that this error occurs when the COM threading model for an application is multithreaded apartment (MTA) instead of single-threaded.

<br />
[System.STAThread]<br />
//[System.MTAThread] will cause error<br />
static void Main()<br />
{ <br />
System.Windows.Forms.Application.Run(new MainForm());<br />
}<br />

Maybe you changed that too?

www.troschuetz.de

Re: Folder Browser Strangeness

Russell Jones2-Jun-04 22:05

Russell Jones

2-Jun-04 22:05

Stefan,

You are a complete and utter hero. I did indeed change the threading model of the application, i had never even thought that that could have caused the problem, i'd got myself convinced that it was something to do with that manifest.

Thanks, at least now i know why it's broke i can test some threories

Russ

PS. i just checked the code, and it was just the [System.STAThread] that was missing, excellent fix, thanks

Re: Folder Browser Strangeness

Stefan Troschuetz2-Jun-04 23:10

Stefan Troschuetz

2-Jun-04 23:10

My pleasure Big Grin | :-D

arachnoid wrote:
i had never even thought that that could have caused the problem

I know what you mean. I only discovered this solution by accident.

arachnoid wrote:
now i know why it's broke i can test some threories

Maybe you can find out why the COM threading model affects the FolderBrowserDialog this way. I never figured that out Frown | :(

www.troschuetz.de

Re: Folder Browser Strangeness

Russell Jones3-Jun-04 0:30

Russell Jones

3-Jun-04 0:30

i'm going to be coding a prog over the weekend that makes extensive use of threads, so hopefully i'll understand more about them soon. I've only ever used threads in Java and VB(Don't go there, it hurt bad), so i'm just trying to get to grips with syntax etc at the moment.

I don't see why the folderbrowser should be sensitive to the threading model when the commondialog isn't, they do pretty much the same thing after all.

I've just found some code on MS site that shows how to use the clipboard from within an MTA thread by spawning an STA thread within your apartment, maybe that'll work for the folderbrowser.

Russ

Task Switching while in Full-Screen mode

strunks2-Jun-04 6:02

strunks

2-Jun-04 6:02

Hi guys, here's my problem.

I have a C# console application and a C# windows forms application running on Windows 2000. The console app runs in a full-screen console, the windows app in a normal window.

Most of the time I will be in full screen mode. But sometimes, my console app will need the help of my windows app, so it makes a remote call to the windows app.

The windows app maximizes iself and takes the focus (user needs to see some information). This causes the console to minimize, and I can see windows desktop, taskbars, all that. After the windows app is done, I want the console app to take the focus back and into fullscreen mode again.

But I can't seem to get that last step to work. Best I've been able to do is make the console window blink on the taskbar. I used DllImport attribute to import user32.dll, and used the WinAPI function SetForegroundWindow to do that.

I basically want to emulate the Alt-Tab functionality. So, since Alt-Tab works there must be a proper way for me to get it to work too. I just don't know what that is. What's the proper way to do this?

Re: Task Switching while in Full-Screen mode

Heath Stewart2-Jun-04 6:39

Heath Stewart

2-Jun-04 6:39

Why is the console app full-screen? This is atypical of a console application. You might consider redesigning your application as a Windows Forms application that can prompt for it's own data. If the console application contains important code you don't want to port, consider using a shared assembly that both the console and Windows Forms application use.

As far as simulating Alt+Tab, you can use SendKeys like so:

SendKeys.Send("%{TAB}");

If you want to do this programmatically, P/Invoke SystemParametersInfo and change the SPI_SETFOREGROUNDLOCKTIMEOUT to 0. See the Platform SDK documentation for the SetForegroundWindow for more information and the reason why.

Microsoft MVP, Visual C#
My Articles

Re: Task Switching while in Full-Screen mode

strunks2-Jun-04 7:01

strunks

2-Jun-04 7:01

Thanks for your prompt reply!

The console application is full screen because it is being exec'd by a legacy application that must run in a full-screen console window. (This legacy system will be replaced by something being written in .NET from scratch in a year or 2, but until then I'm stuck with this as an interim solution).

I am able to switch tasks with no problems if the windows are not full-screen mode windows. I am only having problems if the console window is in full-screen mode.

I don't really want to simulate Alt-Tab. I only mentioned it because Alt-Tab has no problems switching to a full-screen window, so I know there is a way I can do it too. I just want the console application to give itself focus and maximize itself back to full-screen after the windows application has done its thing.

I will go ahead and read up on that documentation, and see if it solves my problem.

C# and MC++

Orhun Birsoy2-Jun-04 6:01

Orhun Birsoy

2-Jun-04 6:01

Is it possible to create an assembly with both C# files and MC++ files?

I have MC++ code that I need it to be private but the code uses it is in C#.

I am open to other suggestions. (ie making the MC++ assembly such that it can only be used by a specific assembly)

Thanks!

Orhun Birsoy

Re: C# and MC++

Heath Stewart2-Jun-04 6:31

Heath Stewart

2-Jun-04 6:31

If you want your MC++ assembly to be used only by another assembly, then use a StrongNameIdentityPermissionAttribute at the assembly level. This also means you should sign your assembly, which is a good idea anyway. To generate a key pair, use:

sn.exe -k KeyFile.snk

Use this key pair for all your assemblies or for assemblies for a product. For more information about the benefits of signing an assembly (to give it a strong name), see the .NET Framework SDK documentation.

Then use the file path (relative to the target directory or an absolute path) in the [assembly: AssemblyKeyFileAttribute] for your projects.

Assuming your C# project is called MyCSharpAssembly.dll with version 1.0.0.0 and a public key (you can get this by running sn.exe -Tp MyCSharpAssembly.dll, using the larger number), add an assembly-level attribute to your MC++ assembly like so:

[assembly: StrongNameIdentityPermission(
  SecurityAction.RequestMinimum,
  Name="MyCSharpAssembly",
  Version="1.0.0.0", // Optional
  PublicKeyToken="0123456789abcdef...........")]

The public key token is very long. You can copy this and concatenate lines yourself. See the documentation for the StrongNameIdentityPermissionAttribute in the .NET Framework SDK for more information and a sample or two.

If MC++ can compile a .NET module (the module contains type metadata and the IL), which I don't remember off hand, you can compile a module and then add it to the C# assembly (along with the module containing the IL from the C# source files) using the csc.exe command-line compilers along with the /addmodule switch.

Microsoft MVP, Visual C#
My Articles

Re: C# and MC++

Orhun Birsoy2-Jun-04 7:13

Orhun Birsoy

2-Jun-04 7:13

Thanks for the info!

I know about signing and security but couldnt find the attribute I am looking for. (StrongNameIdentityPermissionAttribute is exactly what am looking for).

But to iterate the problem, what if I want to use the MC++ assembly (or any other assembly which I want limited use) to be used by some additional assemblies? If I understood your answer I must change(recompile etc) MC++ assembly for each assembly that uses it.

...Reading MSDN....

OK i do not have to provide a Name, but still all the assemblies that uses this limited access assembly had to be signed with the same public-private key, am I correct? Although for my current problem this is perfect, this might not be the case in my future problems Poke tongue | ;-P

.

I will still investigate compiling a mixed language assembly, but I am almost sure that you can not do it with VS IDE.

Orhun Birsoy

Re: C# and MC++

Heath Stewart2-Jun-04 9:01

Heath Stewart

2-Jun-04 9:01

If you want the MC++ assembly to be only used by your assemblies, use the StrongNameIdentityPermissionAttribute but only specify the public key that is paired with a private key you use to sign all your assemblies. This is actually done for several classes throughout the .NET Framework Class Library (.NET FCL) as well.

If you want to use the MC++ assembly with multiple assemblies, then use this approach instead of adding it as a module to other assemblies. It's a waste of size and will be a pain to maintain.

Microsoft MVP, Visual C#
My Articles

SystemPen ?

ongo2-Jun-04 4:13

ongo

2-Jun-04 4:13

Hi When I select control in Visual Studio designer,it draws specific line around a control. Can anybody tell where I can find this pen or brush, or which styles to use to create it. thanks

Salut!

Re: SystemPen ?

Mazdak2-Jun-04 4:35

Mazdak

2-Jun-04 4:35

DO you mean SystemPens class?

Mazy

"One who dives deep gets the pearls,the burning desire for realization brings the goal nearer." - Babuji

Retrieving Username

briby2-Jun-04 3:23

briby

2-Jun-04 3:23

Hi I'm new to C# & .Net and the wonderful world of web services so forgive me if this is a simple and/or stupid question D'Oh! | :doh:

The WebService we are writing needs to determine which user is using it. We are using Digest Authentication (thus handled by Windows before it hits the service) so the user/password login prompt is already taken care of. But how do we determine the user from within the code after this. I tried using,

System.Security.Principal.WindowsIdentity.GetCurrent().Name.ToString()

but this just returned NT AUTHORITY\SYSTEM which is of no real use when I know I typed in TEST1 as the username. Confused | :confused:

Any help would be gratefully received - Thanks in advance

Brian

Re: Retrieving Username

Heath Stewart2-Jun-04 3:38

Heath Stewart

2-Jun-04 3:38

You must set up impersonation in your Web.config file. See the documentation on the <identity> config section in the .NET Framework SDK.

Microsoft MVP, Visual C#
My Articles

Re: Retrieving Username

Atilla Ozgur2-Jun-04 3:57

Atilla Ozgur

2-Jun-04 3:57

In you case I think windows has Authenticated your user and it is using NT AUTHORITY\SYSTEM to run your code.You have to use impersonation so that when you use that code line you will get correct user.
Second solution could be to implement IPrincipal and explicitly set user information.

Education is no substitute for intelligence. That elusive quality is defined only in part by puzzle-solving ability. It is in the creation of new puzzles reflecting what your senses report that you round out the definition. Frank Herbert

Re: Retrieving Username

briby3-Jun-04 0:02

briby

3-Jun-04 0:02

Hi thanks for your reply.
I seem to have found a solution by using Context.User.Identity.Name which returns the userid I was expecting of it

Thanks once again

hiding emails

robmays2-Jun-04 2:40

robmays

2-Jun-04 2:40

is there a way to hide the email address in a multiple To: textbox. i wish to send emails to groups of people but i dont want the recipients knowing each other email addresses?

Re: hiding emails

Hesham Amin2-Jun-04 4:24

Hesham Amin

2-Jun-04 4:24

use BCC (Blind Carbon Copy)
not To..

(this should no be sent in the C# forum)

Re: hiding emails

robmays2-Jun-04 4:29

robmays

2-Jun-04 4:29

yes it took me an hour to figure it out. many thanks

OnClosing

thomasa2-Jun-04 2:22

thomasa

2-Jun-04 2:22

I want to use the:
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
}

what do I add in the #region Windows Form Designer generated code
private void InitializeComponent()
{
}

Something like:
this.OnClosing += new System.Windows.......

Thanks
Thomas

Re: OnClosing

LongRange.Shooter2-Jun-04 2:45

LongRange.Shooter

2-Jun-04 2:45

Open the form in design mode.
Select the form and pull up the property window.
In the top of the property window you will see a lightning bolt; click it.
Now all events for the form are visible.
Locate Closing, place cursor in open box, double-click.
Your method signature and your delegate registration is done for you.

______________________________
The Tao gave birth to machine language.
Machine language gave birth to the assembler.
The assembler gave birth to ten thousand languages.
Each language has its purpose, however humble.
Each language expresses the Yin and Yang of software.
Each language has its place within the Tao.
Beauty exists because we give a name to C#.
Bad exists because we give a name to COBOL.

Re: OnClosing

JackMartinz2-Jun-04 6:50

JackMartinz

2-Jun-04 6:50

Hi,

I am beginner in .NET world. may you give the right address of such "lightning bolt" ...

I have VS.NET 2003, where can I find such thing?

Thanks

Fari

Re: OnClosing

LongRange.Shooter3-Jun-04 2:21

LongRange.Shooter

3-Jun-04 2:21

I am using VS.NET 2003 as well. But the directions remain the same regardless of version.

Just as I said:
Open your form and select it in the designer window.
Select the properties page.
Click the icon at the top that is a lightning bolt.
There is no address per se.

Re: OnClosing

Tom Larsen2-Jun-04 4:37

Tom Larsen

2-Jun-04 4:37

OnClosing is marked as virtual. The framework code calls it when the form is closing. There is nothing to monkey with in the Designer section since it will be called whether you override it or not.

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