Building a System.Uri with a query string - C# Discussion Boards

Elvis_Pretzelator26-Jun-08 5:39

26-Jun-08 5:39

Never mind - I got it. After the text has finished I just call the graphic's FillRectangle() method and fill it with the background color.

Also, while the text is printing I test the height of the VisibleClipBounds and if my text has grown too big then I clear the screen and continue typing:

while(true)
				{
					string result = "";
					for(int i = 0; i < characters.Length; i++)
					{
						// Concatenate the string to create
						// a "tele-type" like effect.
						result += characters[i].ToString();
						gfx.DrawString(result, lucindaFont, green, 10, 10);
						Thread.Sleep(1);
						
						
						// If the string has gotten too big
						// for the visible display,
						// clear the screen and continue
						// the string where we left off.
						SizeF size = gfx.MeasureString(result, lucindaFont);
						if(gfx.VisibleClipBounds.Size.Height < size.Height)
						{
							gfx.FillRectangle(black, gfx.VisibleClipBounds);
							result = "";
						}
					}
					// Start fresh once the string is complete.
					gfx.FillRectangle(black, gfx.VisibleClipBounds);
				}

C# Thread termination issue

Merlock219-Jun-08 8:39

Merlock2

19-Jun-08 8:39

Hey everyone,

I have recently built a client and server application for transferring files across the network. The client application uses two threads: one for transferring file data to the server and another for monitoring incoming messages from the server. Both threads use separate NetworkStream objects for their respewctive tasks.
The job of the listener thread is to listen for messages from the server (which are in the from of strings). Now, when the server disconnects for whatever reason, it'll send a "Disconnect" string message to the client. The listener thread will receive that message, interpret it, and then tell the client application to disconnect from the server.

to illustrate what I mean, here is some code from my client:

//the thread monitoring incoming messages from the server
private Thread m_oListenerThread;

//the thread in charge of file transfer
private Thread m_oTransferThread;

//when 'true', the listener thread exits its loop and terminates
private volatile bool m_bListenerStop;

//when 'true', the transfer thread exits its loop and terminates
private volatile bool m_bTransferThreadStop;

//here is the method run by the listener thread:
StartListening()
{
//some initialization details here
//...
while(m_bListenerStop)
{
//check the NetworkStream object for any data
//...

//if data available, extract string from NetworkStream
//...

//parse message (where sMessage is the extracted string message)
HandleCommand(sMessage);

}
//thread termination details
//...
}

HandleCommand(string z_sMessage)
{
if (z_sMessage == "Disconnect")
{
DisconnectFromServer();
}
}

This is simple enough, but in order to make the application more robust, I need to ensure that all threads have terminated. The only way I know of so far is to call Join(nMiliseconds) on the thread which you want to test. This will cause the calling thread (ex: main) to wait for the thread until nMiliseconds has expired, or the thread is no longer active. Therefore, the DisconnectFromServer() method would look something like this:

DisconnectFromServer()
{
//signal threads to terminate
m_bListenerStop = true;
m_bTransferThreadStop = true;

//close all connection elements
//...

//ensure all threads have stopped
if (m_oListenerThread != null)
{
UpdateStatusDisplay("Waiting for listener thread to terminate...");

//wait for 302 milliseconds for listener thread to terminate. If the thread has not terminated
//by that time, abort thread and throw an exception.
if (m_oListenerThread.Join(302) == false)
{
m_oListenerThread.Abort();
}

if (m_oTransferThread != null)
{

//wait 20 ms for transfer thread to terminate. If the thread has not terminated by that time, abort thread and throw exception.
if (m_oTransferThread.Join(20) == false)
{
m_oTransferThread.Abort();
}
}

//some other termination logic
//...

}

so when x miliseconds has expired and the given thread is not terminated, Abort() is called on the thread to force it to shut down. The problem with the following is that when DisconnectFromServer is called by the listener thread (via HandleCommand()), the thread waits for the function to return so it may keep going and eventually exit its while loop. But it can never do this since DisconnectFromServer() will make it block (due to Join()). The thread is therefore stuck waiting for itself. When the time expires, it simply shuts itself down (using Abort()), and the function never returns, just abruptly stops.
This simply won't do! I have tried using an event in the hopes that the thread would fire a 'shutdown' event, and keep going while the main thread handles the event by calling DisconnectFromServer(), but the same problem arose: the thread waits for the event handler to return.
In short, is there a way to fire events or call methods without being forced to wait for those to return?
Or am I forced to create a third thread which would handle the shutdown procedure? Of course, if I do the latter, I won't really have any means to use Join() on that shutdown thread to make sure it terminated...

Help: I'm new to C#: I want to make a global function

TheFoZ19-Jun-08 8:27

TheFoZ

19-Jun-08 8:27

Hi
As you may be able to tell I am a bit new to C# and I may be attacking this from the wrong angle.

I would like to create global function for the program I am writing. I would like to group these functions together for ease i.e. Customer related functions, general function but enable them to be used by other bits of code. I can do this fine in VB.NET but cannot get them to work in C#.

For Example I would like a function that returns a string that is stripped of all punctuation and is in upper case. This would be a general function and I would like it in its own code file so I can group it together with other ones.

I've had a look in my book and cannot find anything that helps. Is this more of a VB thing and is done differently in C# or am I missing something.

ps I'm using C# 2005 Express Edition.

Many Thanks

The FoZ

Re: Help: I'm new to C#: I want to make a global function

Judah Gabriel Himango19-Jun-08 8:56

Judah Gabriel Himango

19-Jun-08 8:56

Customer-related functions should be instance methods on the Customer class.

For things that don't require an instance, make them static. For example,

public class MyGlobalFuncs
{
    public static void Foo() { }
}

That can be invoked like this: MyGlobalFuncs.Foo()

Life, family, faith: Give me a visit.

From my latest post: "A lot of Christians struggle, perhaps at a subconscious level, about the phrase "God of Israel". After all, Israel's God is the God of Judaism, is He not? And the God of Christianity is not the God of Judaism, right?"

Judah Himango

Re: Help: I'm new to C#: I want to make a global function

TheFoZ19-Jun-08 9:03

TheFoZ

19-Jun-08 9:03

Thanks for that. Its so easy when you know how!

Thanks again.

The FoZ

Re: Help: I'm new to C#: I want to make a global function

Guffa19-Jun-08 11:20

Guffa

19-Jun-08 11:20

TheFoZ wrote:
I would like to create global function

That is not possible. You can use static methods, as Judah suggested, but they are not global.

TheFoZ wrote:
I can do this fine in VB.NET

No, you can't. VB.NET doesn't have any global functions either. If you mean a module, that is just a class where all members automatically become static.

Despite everything, the person most likely to be fooling you next is yourself.

RadioButtonList

john3419-Jun-08 7:59

john34

19-Jun-08 7:59

Hi all,

I have a RadioButtonList attached to a data source and it works perfectly.
However, I have been asked if they can be standard buttons instead of radiobuttons.
What I would like to do is create my own control that inherits all the functionality of the radiobuttonList but renders buttons instead of radiobuttons?
Does anyone have any ideas how I can achieve this?

Thanks!!!
John

Building a System.Uri with a query string

Spacix One19-Jun-08 7:40

Spacix One

19-Jun-08 7:40

I give up, this seems impossible without the UriBuilder class... Well since .NET 1.1 when they made Uri(string, bool) obsolete... So here is my question:

How do you build a System.Uri object in .NET compact framework that points to a "file://" scheme with passed query information?

I've tried every valid (not obsolete) constructor for System.Uri meaning:

* Uri(string)
* Uri(string, UriKind)
* Uri(base, string)
* Uri(Uri, Uri)

It didn't matter which I use because they don't have any affect on the outcome... Every constructor will escape the ? to hex as %3F which is not valid to use with query information!!!

I can do this fine with strings but if I pass a string to the WebBrowser control it'll convert the string to a Uri object and have the problem again. So I need to build the correct Uri object and pass it to the WebBrowser control.

MSDN says the following lie:

http://msdn.microsoft.com/en-us/library/system.uri(VS.80).aspx[^] wrote:
The Uri constructors do not escape URI strings if the string is a well-formed URI including a scheme identifier.

Proven by this example:(start a new smart device application and add this code to the form1.cs file)

using System; 
using System.Collections.Generic; 
using System.ComponentModel; 
using System.Data; 
using System.Drawing; 
using System.Text; 
using System.Windows.Forms; 
 
namespace DeviceApplication1 
{ 
    public partial class Form1 : Form 
    { 
        public int demoValue = 4; 
        public Form1() 
        { 
            InitializeComponent(); 
            this.Load += new EventHandler(this.Form1_Load); 
        } 
 
        void Form1_Load(object sender, EventArgs e) 
        { 
            Uri htmlFile = new Uri(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), UriKind.Absolute); 
            MessageBox.Show("htmlFile.AbsoluteUri=\r\n" + htmlFile.AbsoluteUri); //show how the path is converted correctly into a uri string with a correct scheme 
            string properFormated = string.Format("{0}/DeviceApplication1/test.html?test={1}", htmlFile.AbsoluteUri, this.demoValue); 
            MessageBox.Show("properFormated=\r\n" + properFormated); //show the string is properly formated and escaped correctly! 
            Uri fileWithQuery = new Uri(properFormated); 
            MessageBox.Show("fileWithQuery.PathAndQuery=\r\n" + fileWithQuery.PathAndQuery); //show the error in the Uri not accepting the query content 
        } 
    } 
}

View your results and see my problem Frown | :(

any suggestions? I'm desprate at the moment (this has been bothering me since April!)

-Spacix
All your skynet questions[^] belong to solved

I dislike the black-and-white voting system on questions/answers. Dead | X|

Re: Building a System.Uri with a query string

Judah Gabriel Himango19-Jun-08 8:24

Judah Gabriel Himango

19-Jun-08 8:24

Also from the documentation:

"The URI represented by a Uri instance is always in "escaped" form. The following characters are reserved:

Semi-colon (";" )

Forward slash ( "/")

Question mark ( "?" )

Colon ( ":" )

At-sign ("@")

Ampersand ( "&" )

Equal sign ("=" )

Plus sign ("+" )

US Dollar sign ("$" )

Comma (",")

To transform the URI contained in a Uri instance from an escape encoded URI to a human-readable URI, use the System.Uri.ToString method."

Another thing you could do is call Uri.UnescapeDataString(someString), which will give you back your URI with the proper unescaped characters.

Re: Building a System.Uri with a query string

Spacix One19-Jun-08 9:06

Spacix One

19-Jun-08 9:06

Well I need the Uri object to pass to the WebBrowser control. If you pass it a string it'll convert it to a Uri object thus escaping the string it will navigate to.

In the Normal framework you can use UriBuilder to make a URL with extra unescaped information that is parsed properly by the .PathAndQuery property.

Example: (use a new c# console project on the normal framework 2.0 or higher)

using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int demoValue = 4;
            UriBuilder ub = new UriBuilder("file://", "", -1, Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/DeviceApplication1/test.html", string.Format("?test={0}", demoValue));
            Console.WriteLine("Correct OutPut:\r\n{0}", ub.ToString()); //show path and query content (without errors)
            Console.ReadLine();
        }
    }
}

-Spacix
All your skynet questions[^] belong to solved

I dislike the black-and-white voting system on questions/answers. Dead | X|

Re: Building a System.Uri with a query string

Judah Gabriel Himango19-Jun-08 11:05

Judah Gabriel Himango

19-Jun-08 11:05

It's amazing I've gone so long without knowing about UriBuilder. Thanks for that.

So your issue is only with the .NET Compact Framework? Interesting. I'm afraid I don't have an answer for this. Have you tried asking at the Mobile Development[^] forums? If this turns out to be a bug in the .NET Compact Framework, you ought to report this to the Microsoft Connect site.

Re: Building a System.Uri with a query string

Spacix One19-Jun-08 13:00

Spacix One

19-Jun-08 13:00

Yes, UriBilder is handy as StringBuilder because Uri like String objects are immutable reference types, so if it is changed a new one is made.

Hmmm hadn't though about the Mobile Dev forum (never frequent there) I sort of assumed it was for native code, it'll be worth a shot I guess Big Grin | :-D

Though I do hate to double post this Frown | :(

I do have MSDN support issues left over from the VS2k8 upgrage, think they give bug reports back Wink | ;)

Not like I'd use them anyway... maybe a MVP might look at this Rose | [Rose]

-Spacix
All your skynet questions[^] belong to solved

I dislike the black-and-white voting system on questions/answers. Dead | X|

Over ride GetReaderFromMessage method

Toms Edison19-Jun-08 7:23

Toms Edison

19-Jun-08 7:23

Hi,

I am trying to integrate my application with Serena TeamTrack. I am suppose to receive chinese characters from web service but I am receiving the string as "????????". The suggested solution is to override GetReaderFromMessage method and setting the reader's
encoding to UTF-8 in Visual Studio 2005 C#. But I could not find this method any where. Can any one guide me how and where to override this method?

Thanks

System.Windows.Forms.Panel

zvit19-Jun-08 6:33

zvit

19-Jun-08 6:33

Dear readers!
I am using .net studio 2003,
I have a form that I designed couple of month ago.
Now I was asked to use this from for another purpose.
What I want is to add a panel to this existing form, attach the existing controls to this panel and add another panel to design another view to this form.
After attching the existing controls to this panel I will be able to play with Bring To Front and Send to back properties to design the 2 views of this form.
The problem is that after adding this panel to the existing form the only way to attach existing controls to the panel is by draging them out of the form and draging them back over the panel, after doing that they are attched to the panel.
I need to follow this process for every control, and I am loosing their exact location then before I have started to add the panel.
If anyone knows how to tell an existing control you are attched to a specific panel in windows designer that will be very helpful
Thank you
Zvika

Re: System.Windows.Forms.Panel

Spacix One19-Jun-08 7:22

Spacix One

19-Jun-08 7:22

Press these keys in VS 2k3

[Ctrl] + [Alt] + [T]

Something called the Document Outline Windows should appear (least I think it is in 2k3...) I only have 2k8 and 2k5 installs on this PC. If this doesn't work I'll let you know when I get home, as my laptop has 2k3 installed.

The document outline allows you to position the hierarchy of your winforms in a tree-view format.

-Spacix
All your skynet questions[^] belong to solved

I dislike the black-and-white voting system on questions/answers. Dead | X|

How can we find the our system connected to the WEB ?

Mohammad Dayyan19-Jun-08 5:02

Mohammad Dayyan

19-Jun-08 5:02

Hi
Can anyone tell me, how we can find the our system connected to the WEB with C#?

Thanks

Sorry for my English. I'm a freshman .

Re: How can we find the our system connected to the WEB ?

Ashfield19-Jun-08 5:22

Ashfield

19-Jun-08 5:22

Please clarify what you are trying to do, your question makes no sense.

Bob
Ashfield Consultants Ltd

Re: How can we find the our system connected to the WEB ?

Mohammad Dayyan19-Jun-08 5:30

Mohammad Dayyan

19-Jun-08 5:30

OK, thanks Ashfield. D'Oh! | :doh:

I'm using dial up modem for connecting to Internet. Now I want to write a program that detect, when my computer connected to Internet.

Do you understand what I mean ?

Sorry for my English. I'm a freshman .

Re: How can we find the our system connected to the WEB ?

Ashfield19-Jun-08 6:00

Ashfield

19-Jun-08 6:00

I understand now. The only way I know of (and its a long time since I needed to do this) is to try and open a web page (say google.com) and trap any error messages. There may be other ways, as I say its a long time since I needed to do it.

Hope this helps

Bob
Ashfield Consultants Ltd

Re: How can we find the our system connected to the WEB ?

Gareth H19-Jun-08 6:29

Gareth H

19-Jun-08 6:29

M-Dayyan,

The simplest way (probably) would be to ping an internet address, and if something comes back, you have the internet.

Regards,
Gareth.

(FKA gareth111)

Re: How can we find the our system connected to the WEB ?

Zoltan Balazs19-Jun-08 6:09

Zoltan Balazs

19-Jun-08 6:09

In the System.Net.NetworkInformation namespace check out the NetworkInterface and NetworkChange classes.
The NetworkChange has the NetworkAvailabilityChanged event. I think that is what you want.

Work @ Network integrated solutions | Flickr | A practical use of the MVC pattern

Re: How can we find the our system connected to the WEB ?

Mohammad Dayyan19-Jun-08 6:38

Mohammad Dayyan

19-Jun-08 6:38

Thanks Zoltan .
Can you explain more, I'm new in C#. Sigh | :sigh:

Thanks in advance ...

Sorry for my English. I'm a freshman .

Re: How can we find the our system connected to the WEB ?

Zoltan Balazs19-Jun-08 6:57

Zoltan Balazs

19-Jun-08 6:57

Read this article here[^]

Work @ Network integrated solutions | Flickr | A practical use of the MVC pattern

Re: How can we find the our system connected to the WEB ?

Mohammad Dayyan19-Jun-08 11:18

Mohammad Dayyan

19-Jun-08 11:18

Thanks Zoltan .

Sorry for my English. I'm a freshman .

Problems with FreeImage

Chrisfrmatl19-Jun-08 4:54

Chrisfrmatl

19-Jun-08 4:54

I am using the Free Image library to implement the .pcx image format into my image conveter application. Anyone care to help? THe main problems are The Out of Memory exception and I'm not sure if the library has the availible methods needed to be compatible with the program.

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