Re: How to log before window shutdowned! - C# Discussion Boards

Re: Finalize and Dispose

Guffa6-Oct-07 4:12

Guffa

6-Oct-07 4:12

blumenhause wrote:
Finalize method should be used to clear up only unmanaged resources

Dispose should be used to clean up resources. A finalizer can be used as a backup when implementing the IDisposable interface, but then it's never really meant to be used as the Dispose method should suppress the finalizer.

A finalizer is not guaranteed to be executed. A background thread executes the finalizers in the finalization queue. If the finalizers left in the queue take too long to run when the application ends, the rest of the objects are just thrown away without finalizing.

blumenhause wrote:
where as Dispose method would be called as soon as the object is out of scope

No. The Dispose method is never called automatically. You have to call it explicitly, or use a using block that will call it.

As you always call it explicitly, you always know when it's called.

---
single minded; short sighted; long gone;

Re: Finalize and Dispose

Abhijit Jana6-Oct-07 2:49

Abhijit Jana

6-Oct-07 2:49

Destructors:
These are called by the CLR when the Garbage Collector destroys an object.
In VB.NET => Finalize() Smile | :)

In C# ~MyTestClass() {} Smile | :)

It is not useful to cleanup ur objects coz it is only called by the Garbage Collector Sigh | :sigh:

, if u force then u can do !!! but not recomanded !!!!

Dispose :
The Dispose() method is simply a method you call manually to clean up your
object. it is same like 'object=Nothing' WTF | :WTF:

in VB6 and Dispose() in C# OMG | :OMG:

method.

Good luck !!!! Rose | [Rose]

Happy Programming
-----
Abhijit

Re: Finalize and Dispose

Scott Dorman7-Oct-07 10:52

Scott Dorman

7-Oct-07 10:52

You can also take a look at this article: http://www.codeproject.com/useritems/idisposable.asp[^]

Finalizers are expensive to use in that they are difficult to write properly and add an additional memory cost to your finalizable object. Any time a finalizable object is created it is placed in a special queue that must be checked each time the garbage collection cycle runs. This happens even if you never actually use the object.

The best approach is to implement the IDisposable interface and the Dispose pattern properly, and only implement a finalizer when absolutely necessary.

Scott.

—In just two days, tomorrow will be yesterday.

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Tree View Manipulation.

M. J. Jaya Chitra6-Oct-07 1:50

M. J. Jaya Chitra

6-Oct-07 1:50

Hai Everybody,

I am having a tree view in that the nodes are in a hierarchical manner.

The nodes are checkable.

Now when some child nodes are not selected, then I have to make the parent node check box to have the check state "Indeterminate".

But there is no Check State property of the tree node.

Then i tried to convert it as a check box in code, but it is giving the error indicating that it is not possible.

Can any one give me the solution for this?

Best Regards,
M. J. Jaya Chitra

Re: Tree View Manipulation.

Simon P Stevens6-Oct-07 3:05

Simon P Stevens

6-Oct-07 3:05

Try this: Turn the treeviews checkboxes property _false_ and instead create an ImageList and set the treeviews stateimagelist to the imagelist. You can then create three images in the image list (checked/unchecked/intermediate), and use the nodes stateimageindex (or stateimagekey) to set the state image.

Let me know if it works for you, I've never done this before Smile | :)

Simon

How to log before window shutdowned!

tranglt6-Oct-07 1:26

tranglt

6-Oct-07 1:26

pls, who anyone help me!
I am writting a program to log my PC in a txt file.
when any one start PC it log to txt file and he shutdown it log the txt file.
Thanks

Help you, hepl me

Re: How to log before window shutdowned!

Anthony Mushrow6-Oct-07 1:47

Anthony Mushrow

6-Oct-07 1:47

One hacky type way to stop / slow windows from shutting down, is to show a MessageBox. So, in your apps onClose event (ie. Windows is trying to close your app for shutdown) show a message box while you make your log, then close it.

My current favourite word is: Waffle

Cheese is still good though.

Re: How to log before window shutdowned!

Abhijit Jana6-Oct-07 2:26

Abhijit Jana

6-Oct-07 2:26

Hi, here is ur Ans !!!! Smile | :)

For Detecting Shutdown of Windows Cool | :cool:

private void Form1_FormClosing(object sender, FormClosingEventArgs e)<br />
        {<br />
            if (e.CloseReason == CloseReason.WindowsShutDown)<br />
            {<br />
                //Windows is shutting down!<br />
                // You Write Your Code to generate a log file  <br />
            }<br />
<br />
        }

and For PC Start...just simply u put the exe file in Startup, and on formload........ u can write on same log file !!!!!!!

Good luck Rose | [Rose]

Happy Programming
-----
Abhijit

Client-Server [modified]

Aamu6-Oct-07 1:05

Aamu

6-Oct-07 1:05

greetings to all [ Rose | [Rose]

];

I am working on a client-Server Project.... (C#.net/SQL)
Need to know ::
1. how can i start the Client(.net) application(s) on a LAN from server application(.net)
2. How to run a particular service(Windows) on the client machine from server (which in turn can communicate with the already running client application)

Thanks n Regards,
Aamu

Threading

udikantz6-Oct-07 0:46

udikantz

6-Oct-07 0:46

hi , Thanks in advance for everyone who reads that!

How can i set a thread so that when i start it the calling thread returns to what it did before and the new thread continues from that point , or any other solution with similar effect ?

for example:

<br />
<br />
public void Some_Event(Object sender , EventArge e)<br />
{<br />
    Console.writeline("Im the Old Thread: {0}",Thread.CurrentThread.Name);<br />
    //Some code i dont know how to implement<br />
    <br />
    Console.writeline("Im the new Thread: {0}",Thread.CurrentThread.Name);<br />
<br />
    SomeForm sf = new SomeForm(((String)sender).username);<br />
<br />
}<br />
<br />

Net

Re: Threading

lmoelleb6-Oct-07 1:00

lmoelleb

6-Oct-07 1:00

Google finds this.[^]

You might also want to look at the TreadPool class (Google it). It provides a bit less control over the treads, but in returns handles queuing requets, creating threads etc automatically.

Re: Threading

udikantz6-Oct-07 1:52

udikantz

6-Oct-07 1:52

if i wouldnt read that msdn or google i wouldnt ask here ,

in the msdn they only show examples of
Thred t = new thread(ThreadStart(target));

if you read my question i need something a bit different , dont know if its possible thats why im asking.

Net

Re: Threading

lmoelleb6-Oct-07 3:35

lmoelleb

6-Oct-07 3:35

beleive me, a lot of people do NOT consult MSDN or Google before asking, you are the (positive) exception here. Smile | :)

But to answer your question - No, you do not need anything different.

Where you have written "//Some code i dont know how to implement" the code (pseudo code, I am not sure delegate names and signatures match - find them in MSDN) is as follows:

<br />
ThreadPool.QueueUserWorkItem(new WaitCallback(ThreadMethod));<br />
} // Here you end the current method letting the main thread return to what it did before<br />
<br />
private void ThreadMethod() // give it a signature matching the delegate<br />
{<br />
  //Perform thread code here.<br />
}<br />

Depoending on how much control you want with the thread, you can use one of the alternatives (create a Thread object etc) instead of the ThreadPool.

If you REALLY want it in the same method you can replace the "new WaitCallback(ThreadMethod)" part with an anonymous delegate. But I really recommend you try to think of starting threads as follows:
1) The creating thread continues execution in the current method
2) The new thread starts running in a new method/scope.

it will help you later on as this is how the thread methods are designed - and how they are used by most developers.

Re: Threading

udikantz6-Oct-07 6:16

udikantz

6-Oct-07 6:16

The anonymous delegate did the trick ,
Thanks
i did something like that if that's what you mean:

<br />
public void my_multi_threaded_method()<br />
{<br />
    Console.WriteLine("calling thread");<br />
<br />
    Thread t = new Thread(ThreadStart(delegate() <br />
    {<br />
        Console.WriteLine("child thread");<br />
        //code<br />
    });<br />
    t.start<br />
}<br />

Net

how to check the files are exist or not in a floder

ramyanaidu5-Oct-07 22:45

ramyanaidu

5-Oct-07 22:45

plz any ine help me

i need a code for finding whether a file is exisisting in the folder if exist display the file woth some text or not create the file with some text and displaying message that file is created successfully using c#

Re: how to check the files are exist or not in a floder

Hessam Jalali5-Oct-07 23:03

Hessam Jalali

5-Oct-07 23:03

you can use System.IO.File.Exists(string path) method to check whether the file exists or not.

good luck

Re: how to check the files are exist or not in a floder

Abhijit Jana5-Oct-07 23:52

Abhijit Jana

5-Oct-07 23:52

using System;
using System.IO;
using System.Collections;

public class FileHandling
{
public static void Main(string[] args)
{
foreach(string path in args)
{
if(File.Exists(path))
{
// Your code should run here

}
else if(Directory.Exists(path))
{
//Your code should run here
}
else
{
Console.WriteLine("{0} is not a valid file or directory");
}
}
}

Happy Programming
-----
Abhijit

Cancelling a background worker

Muammar©5-Oct-07 22:40

Muammar©

5-Oct-07 22:40

It's me again Blush | :O