C# Discussion Boards - CodeProject

Problem with System.Diagnostics.Process.Start [modified]

26-Oct-09 1:43

Monitor.Wait is not a replacement or alternative for Monitor.TryEnter. The current method

bool TryEnter(Object obj)

is being obsoleted because the suggested replacement is

void TryEnter(Object obj, ref bool lockTaken)

So there isn't really any major change, just that the boolean will now be returned as a by ref parameter instead of a return value from the method.

(If you want to know the reasons for why the old TryEnter is being made obsolete you can read about it here[^])

Monitor.Wait()[^] is totally different. It basically releases the lock on an object and blocks the current thread until a different thread called Monitor.Pulse() to signal that the thread can reacquire the lock and continue.

Simon

Slavakr26-Oct-09 1:10

Slavakr

26-Oct-09 1:10

if i write this way, then it works:

System.Diagnostics.Process.Start(@"C:\\if.log");

But if i want the text from other label like label3.Text, and it has the same path, then it doesnt work.

System.Diagnostics.Process.Start(@"{0}", label3.Text);

I make the user to open the file, then the label saves the file path and if the program needs to open the file, then it doesnt work, it works only if i write the path myself. Maybe someone knows how to use this method without saving the path to a label, then that would be better. Can someone help me with this please? Sigh | :sigh:

modified on Monday, October 26, 2009 6:32 AM

Re: Problem with System.Diagnostics.Process.Start

Simon P Stevens26-Oct-09 1:15

Re: Problem with System.Diagnostics.Process.Start

26-Oct-09 1:15

With the second way, you don't need to type double slashes into the text box because the text box already handles this. Could that be the problem?

You also don't need the @ sign if you are putting double slashes in the string. (Or keep the @ sign and you don't need to use double slashes.)

If not, try posting more details about what "doesn't work". Does it cause an exception? Post the type, message and a stack trace from the exception.

Simon

Slavakr26-Oct-09 1:31

Slavakr

26-Oct-09 1:31

Thank you Simon, it worked without @ Smile | :)

. The double slashes are because it puts automatically when it gets the path. I have tested it, to see how looks the path, and it used double slashes.

Re: Problem with System.Diagnostics.Process.Start

Simon P Stevens26-Oct-09 2:03

Show Windows Desktop, nothing else...

26-Oct-09 2:03

slavakr wrote:
it worked without @

Cool.

The double slashes are because the single slash in a string is an escape character, so you can't just have one on it's own. The first escapes the next character.

So in the string "c:\test" the \t will become a tab (see here[^])

So instead it's common to put "c:\\test" which means the first slash just escapes the second and the string will become a correct path.

If you want to have a string without escape characters, you can put the @ sign at the beginning, and it will not use any escape sequences in the string. So @"c:\test" will not escape the t like it would if you missed out the @ sign. So with the @ sign in place, there is no need to use double slashes.

There's more about escape characters on Wikipedia[^]

Simon

Naruki26-Oct-09 0:39

Naruki

26-Oct-09 0:39

C# newbie here.

I am using the wonderful John’s Background Switcher[^] to keep my wallpaper fresh and interesting, and I realized I'd like to make use of it for my screen saver, too.

Since he does not have an option for that, I thought I'd try learning how to make a little C# screensaver form that just showed the wallpaper as is.

That was about a week ago.

In my experiments, I decided there are two general ways of solving this problem:
1) create a blank desktop and display it with no apps running (or my own app, which wouldn't do anything but listen for a keypress)

2) hide everything on the existing desktop, leaving only the wallpaper visible

I have found code samples for creating desktops, but nothing that I can figure out how to make work with my tiny brain. So I concentrated on option 2.

This requires 3 steps:
a) hide all shortcut icons
b) hide all running taskbar icons [& the taskbar]
c) make wallpaper visible through my app's form

C seemed pretty easy from my Java perspective: just throw up a glasspane and be done. C# begs to differ with me.

I did finally find a way to keep my app transparent enough without allowing click-thru (mouse clicks activating the visible icons behind my transparent form), or so I think. Regardless, it won't matter if I hide everything that shouldn't be shown.

I have just now figured out how to reliably hide shortcut icons and redisplay them at will. This problem was a lot harder than it should have been because everybody seems to say "icons" when they mean the stuff on the taskbar (naturally, I assumed they'd use the term tasks or some such - silly me). But now it's good.

So now I am stuck on step B - hide everything else. I did find a PInvoke for toggling the desktop, but it has some nasty drawbacks:
- it requires including a DLL with the screen saver executable
- it does not let me know if things are visible or not
- the restore does not put things back the way they should be

I really think the first option is best (create an empty desktop), but I don't know how to make that work. If anyone has the right solution...

Barring that, does anyone know how to "properly" hide all desktop icons, and then how to restore them as they were?

No code shown because my stuff is a horrible mess and would only make this post even more confusing. But I'll post whatever bits are requested, and of course when I get it working I'll share the whole finished steaming pile of code.

よろしくおねがいします。

Narf.

Simon P Stevens26-Oct-09 1:11

26-Oct-09 1:11

It seems like you are overcomplicating the problem.

I don't understand why you don't just make your app full screen and display the required image over the top of everything else.

Simon

Naruki26-Oct-09 5:08

Naruki

26-Oct-09 5:08

Well, obviously the big factor here is learning. I'm doing this because I want to know something about C# and Windows APIs and stuff.

But more specifically to your point, because the "required image" changes from time to time. The wallpaper changer automatically pulls down random images from the net.

In order to reproduce all of that functionality, I'd have to do something very complex indeed, and that's definitely beyond the scope of my little project.

My app IS fullscreen, because it has to cover all the other apps and prevent them from receiving keystrokes/mouse movements. I had to make it transparent so I could see the stuff below, but do that without letting the mouse clicks or keystroke slip through.

In Java, that means a glasspane. In C#, it means a headache. At least so far as I know. Total newb here.

Narf.

Shorgov26-Oct-09 1:16

Shorgov

26-Oct-09 1:16

I think you are making your life miserable.

Sacha Barber has a great article about the screen savers
WPF : A 3D screensaver written in WPF[^]

You can check and Jacob Jordan's article
Making a C# screensaver[^]

How to get contents of cache memory in c#?

Naruki26-Oct-09 5:20

Naruki

26-Oct-09 5:20

No, it's Windows that is making my life miserable. I am just trying to learn how to make use of the APIs to do something that, conceptually at least, is very straightforward.

The second link is one I already used. I think it was the third one I found for making C# screen savers. Also, Visual Studio 2005 comes with a screen saver learning kit, and I used that one, too. I know the basics already.

But my only problem now is I want to view the wallpaper - and nothing else - beneath my transparent pane, while still preventing any keystrokes etcetera from getting through.

Technically my problem is not knowing how to do that, but that's why I'm asking for help.

The first link is also interesting, and I may want to look at it later, but it's for a different kind of project than what I am trying to do here. Thanks anyway.

Narf.

Swapnil 200926-Oct-09 0:24

Swapnil 2009

26-Oct-09 0:24

Hello evertbody,

I wanted to know how to find the contents of cache memory in c#.Can anobody give a hint or a code snippet for this problem..

Thanking in advance

Swapnil

Abhishek Sur26-Oct-09 0:32

Abhishek Sur

26-Oct-09 0:32

Cross post from different ID ... WTF | :WTF:

Why do you need to create more than one id for you ... ?? D'Oh! | :doh:

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
Microsoft Bing MAP using Javascript
CLR objects in SQL Server 2005
Uncommon C# Keywords/xml>

Swapnil 200926-Oct-09 0:42

Swapnil 2009

26-Oct-09 0:42

Ya right I want to get contents of computers cache memory..
actually I want to get contents of mozzila's cache memory...
Do you have any Idea?

Jaiprakash M Bankolli26-Oct-09 0:43

Jaiprakash M Bankolli

26-Oct-09 0:43

I didn't understand your question properly. Are you saying you want to scan Cache and find if the required info has been present?

Regards,
Jaiprakash M Bankolli
jaiprakash.bankolli@gmail.com
My Blog
Suggestions for me
Visit:www.OracleQuest.com

problem with custom control properties value

Swapnil 200926-Oct-09 1:04

Swapnil 2009

26-Oct-09 1:04

Hi,

Actually I am developing a tool to check the performance of a site. so whenever I enter a site I want to know is the contents of the url are present in cache or not and if present want to display the contents. So do you have any idea about it. I want to do this in c#.

Lyon Sun26-Oct-09 0:18

26-Oct-09 0:18

Hi, all,

I am doing with a custom control in WinForms, and there is one customed integer type property, say, currentLine, declared in that custom control class with the following code:

private int currentLine;

public int CurrentLine
{
    get { return currentLine; }
    set { currentLine = value; }
}

but this property's value should be restricted between 1 and 100.
How to make this happen, so that a value smaller than 1, or bigger than 100 is rejected to be entered in properties window at designer time?
Any suggestions are so much appreciated!! Thanks.

Br!

Sun

Message Closed

26-Oct-09 0:35

stancrm

26-Oct-09 0:35

Message Closed

modified 23-Nov-14 7:30am.

Lyon Sun26-Oct-09 0:45

26-Oct-09 0:45

thank you, stancrm,

I've tried this, I added one method, OnCurrentLineChanged() in the SET of that property, and the method is as follows:

private void OnCurrentLineChanged()
{
      if (currentLine < 1 || currentLine > 100)
      {
          throw new System.ArgumentException("Property value is not valid", "original");
      }
}

However, I don't know for what reason, it doesn't work when I go designer window and try a number like 123.
Any idea with this?

Br!

Sun

Lyon Sun26-Oct-09 1:01

26-Oct-09 1:01

Hi, stancrm,

You are right. I did this exception in the wrong place, and with a wrong exception name as well Roll eyes | :rolleyes:

. I noticed it after I read Sur's reply.
Anyway, Thank you two!! A lot!

Br!

Sun

Abhishek Sur26-Oct-09 0:42

Abhishek Sur

26-Oct-09 0:42

Leapsword Sun wrote:
public int CurrentLine
{
get { return currentLine; }
set { currentLine = value; }
}

change this to

public int CurrentLine
{
     get { return currentLine; }
     set { 
           if(value < 1 || value > 100) throw new ApplicationException("Invalid Input");
            currentLine = value; 
         }
}

This will throw an exception for invalid values. You can modify this according to your need. Just modify the set portion of CurrentLine

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
Microsoft Bing MAP using Javascript
CLR objects in SQL Server 2005
Uncommon C# Keywords/xml>

Lyon Sun26-Oct-09 0:59

How to get contents of cache memory in c#?

26-Oct-09 0:59

Hi, Sur,

Thank you so much! This solved my problem. Really, thanks a lot!!

Br!

Sun

snakeway42026-Oct-09 0:17

snakeway420

26-Oct-09 0:17

Hello evertbody,

I wanted to know how to find the contents of cache memory in c#.Can anobody give a hint or a code snippet for this problem..

Thanking in advance

Swapnil