Re: Blackhole string! - C# Discussion Boards

12-Mar-09 4:40

Xmen wrote:
if (pictureBox1.ClientRectangle.Contains(x, y))

It is not sufficient to keep the cursor position inside the PictureBox, that way the Panel can still stick out on any of 4 sides.

One needs to check PictureBox.Bounds.Contains(Z) where Z is either the new Panel.Bounds
or the new Location of two Points (e.g. topleft and bottomright).

Smile | :)

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Blackhole string!

Member 349379912-Mar-09 2:37

12-Mar-09 2:37

Below is my code to add a chat message to a multiline text box.

I have tested the parameters, when I run them on messagebox's they output the proper value, but
when I combine them:

"chatView.Text = chatView.Text + Environment.NewLine + myName + ": "+ myText;"

Only "myName" shows up on each line.

What am i doing wrong?

public delegate void chatMessageCallBack(string myName, string myText);
        private void chatMessage(string myName, string myText)
        {
            chatView.Text = chatView.Text + Environment.NewLine + myName + ": "+ myText;
        }
        private void addChatMessage(string myName, string myText)
        {
            if (chatView.InvokeRequired)
            {
                chatMessageCallBack d = new chatMessageCallBack(chatMessage);
                Invoke(d, new object[] { myName, myText });
            }
            else
            {
                chatView.Text = chatView.Text + Environment.NewLine + myName + ": " + myText;
            }
        }

musefan12-Mar-09 2:54

12-Mar-09 2:54

well if your getting the myName part, i would have to say that your myText value is null or empty.

Try putting in a MessageBox in your chatMessage function and output the two values to make sure they contain the data you expect.

I assume you are getting the ": " along with myName?

Member 3493799 wrote:
I have tested the parameters, when I run them on messagebox's they output the proper value, but
when I combine them:

my bad, i missed that line

Life goes very fast. Tomorrow, today is already yesterday.

musefan12-Mar-09 3:09

12-Mar-09 3:09

very strange,

try replacing the environment.newline with something else to see if the text shows

Life goes very fast. Tomorrow, today is already yesterday.

Member 349379912-Mar-09 3:11

12-Mar-09 3:11

I know!

Nothing works in combination.

Heck, even when I remove the newline stuff and just have myName + myText, it only shows myName...

weirdest thing ever..

musefan12-Mar-09 3:13

12-Mar-09 3:13

what about just textBox.Text = myText;?

Life goes very fast. Tomorrow, today is already yesterday.

Luc Pattyn12-Mar-09 3:12

12-Mar-09 3:12

Member 3493799 wrote:
Invoke(d, new object[] { myName, myText });

IMO should be chatView.Invoke(...)

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Member 349379912-Mar-09 3:20

12-Mar-09 3:20

Tried it, didnt work Frown | :(

Heres the packet decoding scheme:

myName = dataSender
myText = dataMessage

[StructLayout(LayoutKind.Sequential, Pack = 1)]
                public struct rawCncPacket
                {
                    // IP
                    public byte IPVerLen;
                    public byte IPTOS;
                    public short IPLength;
                    public short IPID;
                    public short IPOffset;
                    public byte IPTTL;
                    public byte IPProtocol;
                    public short IPChecksum;
                    public int IPSrcAddr;
                    public int IPDestAddr;
                    // UDP
                    public short UDPsourcePort;
                    public short UDPdestPort;
                    public short UDPLength;
                    public short UDPcheckSum;
                    // CNC
                    public int CNCpacketDirection;
                    public int CNCpacketNumber;
                    public int CNCpacketSource;
                    public int CNCpacketDest;
                    public short CNCpacketPort;
                    public short CNCpacketHeaderEnd;
                    // Data
                    public byte dataType; // 1
                    public byte[] dataSenderBytes;
                    public string dataSender; // 12
                    public byte[] dataMessageBytes;
                    public string dataMessage; // 24
                    public int dataPackOne;
                    public int dataPackTwo;
                    public byte dataPackEnd;

                    public rawCncPacket(byte[] packet)
                    {
                        // IP Header section
                        System.IO.MemoryStream stm = new System.IO.MemoryStream(packet, 0, 94);
                        System.IO.BinaryReader rdr = new System.IO.BinaryReader(stm);
                        IPVerLen = rdr.ReadByte();
                        IPTOS = rdr.ReadByte();
                        IPLength = rdr.ReadInt16();
                        IPID = rdr.ReadInt16();
                        IPOffset = rdr.ReadInt16();
                        IPTTL = rdr.ReadByte();
                        IPProtocol = rdr.ReadByte();
                        IPChecksum = rdr.ReadInt16();
                        IPSrcAddr = rdr.ReadInt32();
                        IPDestAddr = rdr.ReadInt32();
                        // UDP header section
                        UDPsourcePort = rdr.ReadInt16();
                        UDPdestPort = rdr.ReadInt16();
                        UDPLength = rdr.ReadInt16();
                        UDPcheckSum = rdr.ReadInt16();
                        // CNC header section
                        CNCpacketDirection = rdr.ReadInt32();
                        CNCpacketNumber = rdr.ReadInt32();
                        CNCpacketSource = rdr.ReadInt32();
                        CNCpacketDest = rdr.ReadInt32();
                        CNCpacketPort = rdr.ReadInt16();
                        CNCpacketHeaderEnd = rdr.ReadInt16();
                        // Data section
                        dataType = rdr.ReadByte();
                        dataSenderBytes = rdr.ReadBytes(12);
                        dataMessageBytes = rdr.ReadBytes(24);
                        dataSender = System.Text.ASCIIEncoding.ASCII.GetString(dataSenderBytes);                      
                        dataMessage = System.Text.ASCIIEncoding.ASCII.GetString(dataMessageBytes);
                        dataPackOne = rdr.ReadInt32();
                        dataPackTwo = rdr.ReadInt32();
                        dataPackEnd = rdr.ReadByte();
                    }
                }

Luc Pattyn12-Mar-09 4:26

12-Mar-09 4:26

Hi,

not sure why I am getting all this, thanks anyway.

some remarks:

1.
either this struct has strict requirements or it has not.
if it has, I doubt it should hold both public byte[] dataSenderBytes; and public string dataSender; // 12
same for public byte[] dataMessageBytes; and public string dataMessage; // 24
if it has not, don't see why it should need a Pack=1 attribute

2.
your problem is with string handling.
in the native world (C, C++) strings consist of 8-bit characters (or 16-bit wide characters) and they end on the first ASCII NULL character (byte value zero), which means the NULL character itself cannot be embedded in a string.
in the managed world strings can contain any character you choose; if you give 12 bytes (dataSenderBytes) to ASCII.GetString() it probably returns a 12-character string of which several could be NULL (or \0).

So I suggest you get the meaningful length of those strings somehow from the byte[] or from the native world, then use ASCIIEncoding.GetString(Byte[], 0, length)

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Nagy Vilmos12-Mar-09 3:19

Nagy Vilmos

12-Mar-09 3:19

Running it within the IDE, put some breakpoints in on the entry to each of your methods.
Step through and see what the values are that are being received.
Maybe instead of:

chatView.Text = chatView.Text + Environment.NewLine + myName + ": "+ myText;

Try:

String newText = chatView.Text + Environment.NewLine + myName + ": "+ myText;
chatView.Text = newText;

Then after newText has been created you can be sure the correct value is going ito the RHS of the expession.
This is debug problem, you just need to establish the values at every step of the process.

Panic, Chaos, Destruction.
My work here is done.

Member 349379912-Mar-09 3:30

12-Mar-09 3:30

Used breakpoints, saw the values and they were correct.

newText was highlighted in red though when I got to the" chatView.Text = newText" (dont know what that means: VS2008).

myName = "test"
myText = "ETST13245"

newText	"\r\Test\0\0\0\0\0\0\0: ETST13245\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"	string

Nagy Vilmos12-Mar-09 3:35

Nagy Vilmos

12-Mar-09 3:35

Member 3493799 wrote:
\0\0\0\0\0\0\0

As soon as it's hitting the null char, the display is being truncated.

Panic, Chaos, Destruction.
My work here is done.

Member 349379912-Mar-09 3:36

12-Mar-09 3:36

Cheers, that makes sense, will change it accordingly.

Nagy Vilmos12-Mar-09 3:42

Nagy Vilmos

12-Mar-09 3:42

You are welcome. Blush | :O

After yesterday's retardfest it is nice to have a real question to answer.

BTW My first port of call when code is not behaving is to debug the thing to smithereens until I find the problem. My second is a call for Port.

Panic, Chaos, Destruction.
My work here is done.

Member 349379912-Mar-09 3:45

12-Mar-09 3:45

Opening a good old Port may be the solution to many a networking problem Wink | ;-)

Multi-Threading Question

Programm3r12-Mar-09 2:01

12-Mar-09 2:01

Hi all,

I have created a multi-threaded TCP/IP server. Each client connection runs in it's own thread.
The problem that I have it when I close the server and there are still clients connected. The thing is that the client threads remain active.

How can stop / dispose of the client threads so that the server can be closed for good?

Many thanks in advance

Kind regards,

The only programmers that are better C# programmers, are those who look like this -> Green Alien | [Alien]

Programm3r
My Blog: ^_^

musefan12-Mar-09 2:11

12-Mar-09 2:11

well you need to handle connections when you close down the server.

You should have a list of all connected clients, right?

so you will want to stop incomming connections.
then you can abort all client threads, preferable after sending information to the client about the shut down

Life goes very fast. Tomorrow, today is already yesterday.

Programm3r12-Mar-09 2:42

12-Mar-09 2:42

musefan wrote:
You should have a list of all connected clients, right?

Yes.

musefan wrote:
then you can abort all client threads

The only thing is that the client threads spawn out of another thread that is listening for any incoming connections. If a new connection is accepted by the listen thread the listen thread spawns a new thread for that connections. Thus I do not have the handle to each of the client threads that have been spawned, well I think so anyway.

Many thanks for your response
Kind regards,

The only programmers that are better C# programmers, are those who look like this -> Green Alien | [Alien]

Programm3r
My Blog: ^_^

Member 349379912-Mar-09 2:44

12-Mar-09 2:44

Did you use Socket.beginAccept?

musefan12-Mar-09 2:47

12-Mar-09 2:47

well you may want to change it so you store you connections somewhere you can access.

you could try using a static collection of threads. that way they can be accessed from both your connection handling thread and you main thread.

Life goes very fast. Tomorrow, today is already yesterday.

Programm3r12-Mar-09 2:59

12-Mar-09 2:59

Mmmm .... yes I think that can do the trick.

Is it possible to terminate a thread if one has the thread handle?

Thanks again
Regards,

The only programmers that are better C# programmers, are those who look like this -> Green Alien | [Alien]

Programm3r
My Blog: ^_^

musefan12-Mar-09 3:08

12-Mar-09 3:08

I assuming its system.Threading.Thread, you can use .Abort to end the thread.

Life goes very fast. Tomorrow, today is already yesterday.

Programm3r12-Mar-09 3:28

12-Mar-09 3:28

musefan wrote:
I assuming its system.Threading.Thread

Yes.

Thanks

The only programmers that are better C# programmers, are those who look like this -> Green Alien | [Alien]

Programm3r
My Blog: ^_^

Luc Pattyn12-Mar-09 3:19

12-Mar-09 3:19

Hi,

if all you need is for the server to be able to stop whenever it wants to, turn all the client-serving threads into background threads by setting their IsBackground property true. FYI: ThreadPool threads and BackgroundWorkers always are background threads, so they can't prevent your app from exiting.

however if you need to communicate with the clients about the imminent shutdown, obviously you would need to keep a list and provide the appropriate code.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Programm3r12-Mar-09 4:16