Re: Problem with reading Bytes - C# Discussion Boards

Can you show me with some code how to do because I could not do it.

Did you write the code above? Because if you did, you would know very easily how to do this.
If this is a homework assignment of some kind, then you need to make an honest attempt.
Try writing a new class as I described above and then ask questions based on that. You'll get loads of support here if you approach it that way. Asking us to simply give you the answer teaches you nothing and at some point, some senior dev out there who will mentor you in the workforce later on will curse us for doing so if we did.

I wasn't, now I am, then I won't be anymore.

Hi,

I am building a simple windows phone 7 app. I need to pass more that one data item between pages. I know you need to make a small change to sending one data item across but im not sure what this change is. Currently I send one item across like this:

phoneApplicationPage.NavigationService.Navigate(new Uri("/Pages/View_Stickies.xaml?string=" + info, UriKind.RelativeOrAbsolute));

Where in this case info is the string sent.

I unpack it on page 2 like this:

protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
{
    if (this.NavigationContext.QueryString.ContainsKey("string"))
    {
       string GPS = this.NavigationContext.QueryString["string"];
       MessageBox.Show(GPS);
    }

    base.OnNavigatedTo(e);
}

Im sure there is a very simple answer to the question and any help would be great.

Thanks

As you are passing a query string across, all you need to do is add the second key value pair after a &, so your example could become:

C#

string.Format("/Pages/View_Stickies.xaml?string={0}&id={1}", info, id)

I'm not a stalker, I just know things. Oh by the way, you're out of milk.

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Onyx

Thank you very much.

You're welcome.

I'm not a stalker, I just know things. Oh by the way, you're out of milk.

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Onyx

Hi ,

I have array and I am try to read as a block where block start from 55 55 and end with 204 204 and within the start and the end I am read message where each message should start with 99 and end with 13 (all as a Hex) and if the message length is 30 I will do operation and if it is 6 I will do another operation.

but I am receive some exceptions when I read different bytes from different bytes.

Here's a sample from different blocks ( Which Stored In arraylist called :VopMessageDetails)

55  55  1C  09  0A  0B 
 
99  1E  3F  41  56  42  30  31  31  30  31  31  4E  4E  20  20  30  31  30  20  20  20  20  01  08  42  0B  59  CF  0D

99  1E  3F  41  56  42  30  32  31  30  31  32  4E  4E  20  20  30  32  30  20  20  20  31  02  08  93  0D  D3  CE  0D

99  0A  41  2F  01  08  E7  03  00  0D

99  1E  3F  41  56  43  30  33  31  30  31  32  4E  4E  20  20  30  33  30  20  20  20  20  03  08  58  0F  98  CE  0D

99  1E  3F  41  56  41  31  35  31  30  31  32  4E  4E  20  20  31  35  30  20  20  20  20  04  08  00  00  00  00  0D

CC  CC  

==============================================

55  55  1C  09  0A  0C  
  

CC  CC  

============================================
55  55  1C  09  0A  0D


55 55 1B 0B 0A 17 99 1E 3F 48 56 41 30 35 31 30 
32 36 4E 4E 20 20 30 35 30 20 20 20 20 01 00 32 
1E F4 D5 0D CC CC 55 55 1B 0B 0B 04 CC CC   

99  0A  41  2F  02  08  78  03  00  0D 

CC  CC  

===========================================

55  55  1C  09  0A  0E  

99  1E  3F  41  56  41  31  33  31  30  31  35  4E  4E  20  20  31  33  30  20  20  20  20  01  08  A0  0B  F7  DB  0D

99  0A  41  2F  01  08  E7  03  00  0D

99  1E  3F  41  56  42  30  31  31  30  31  35  4E  4E  20  20  30  31  30  20  20  20  20  02  08  42  0B  59  CF  0D

99  0A  41  2F  02  08  E7  03  00  0D

99  1E  3F  41  56  43  30  33  31  30  31  35  4E  4E  20  20  30  33  30  20  20  20  20  03  08  58  0F  98  CE  0D

99  0A  41  2F  03  08  E7  03  00  0D

99  1E  3F  41  56  41  30  34  31  30  31  35  4E  4E  20  20  30  34  30  20  20  20  20  04  08  DB  10  C5  CE  0D

99  0A  41  2F  04  08  E7  03  00  0D

CC  CC
================================
55 55 16 0C 0D 2B 99 1E 3F 41 56 41 30 36 31 33 
34 33 4E 4E 20 20 30 36 30 20 20 20 20 01 08 C8 
11 4E D2 0D 99 1E 3F 48 56 41 30 31 31 33 34 34 
59 59 53 34 30 34 30 43 4C 59 36 01 00 0E 1F 2C 
DA 0D 99 1E 3F 42 56 41 31 33 31 33 34 35 4E 4E 
20 20 31 33 30 20 20 20 20 01 0A D4 0E 48 DE 0D 
CC CC 55 55 16 0C 0E 13 99 1E 3F 41 56 41 30 33 
31 34 31 39 4E 4E 20 20 31 33 30 20 20 4E 20 01 
08 92 0C 64 D4 0D 99 1E 3F 41 56 41 30 38 31 34 
31 39 4E 4E 20 20 30 38 30 20 20 20 20 02 08 90 
11 EA D6 0D CC CC

and here's My code

<br />
     #region 1: Count Numbers of blocks.<br />
                int blockCounter = 0;<br />
                int countNumberOfBytes = 0;<br />
                for (int i = 0; i < VopMessageDetails.Count; i++)<br />
                {<br />
                    if (VopMessageDetails[countNumberOfBytes].ToString() == "85")<br />
                    {<br />
                        /* <br />
                         * I am use this loop becasuse the first byte is not 204<br />
                         * so it will through expection so I make it go to first condition<br />
                         * till it reach to the require condition which is else if condition.<br />
                        */<br />
                    }<br />
                    else if (VopMessageDetails[countNumberOfBytes].ToString() == "204" & VopMessageDetails[countNumberOfBytes - 1].ToString() == "204")<br />
                    {<br />
                        blockCounter++;<br />
                    }<br />
                    countNumberOfBytes++;<br />
<br />
                }<br />
                Console.WriteLine(blockCounter);<br />
                #endregion<br />
<br />
                // 2 : Read Each Block As Alone.<br />
<br />
<br />
<br />
<br />
                // To Store Each block in catchBlockBytes Array where each Index represent a block.<br />
                List<string>[] catchBlockBytes = new List<string>[blockCounter];<br />
                //After we Determine Number of Block to catchBlockBytes , Reassignment blockCounter to Zero to set index of each object step by step.<br />
                blockCounter = 0;<br />
                catchBlockBytes[blockCounter] = new List<string>();<br />
<br />
                // To Get the Number of Previous Bytes.<br />
                int PrevBlockCounter = 0;<br />
<br />
                // Catch Each Block.<br />
                for (int k = 0; k < VopMessageDetails.Count; k++)<br />
                {<br />
                    if (VopMessageDetails[0 + PrevBlockCounter].ToString() == "85" & VopMessageDetails[1 + PrevBlockCounter].ToString() == "85")<br />
                    {<br />
                        if (VopMessageDetails[k].ToString() != "204")<br />
                        {<br />
                            catchBlockBytes[blockCounter].Add(VopMessageDetails[k].ToString());<br />
                        }<br />
                        else<br />
                        {<br />
                            // I am 2 to K because the previous if condtion will not add the last 2 bytes ( 204 and 204)<br />
                            // So I am add 2 to start again from 85 and continue with condition.<br />
                            PrevBlockCounter = k + 2;<br />
                            // blockCounter++;<br />
                            k++;<br />
<br />
                            if (VopMessageDetails[PrevBlockCounter - 1].ToString() == "204" & VopMessageDetails[PrevBlockCounter - 2].ToString() == "204")<br />
                            {<br />
                                blockCounter++;<br />
                            }<br />
<br />
<br />
                            // Condition Target : to stop add new object as a item if there is no bytes. <br />
                            if (k != VopMessageDetails.Count - 1)<br />
                            {<br />
                              catchBlockBytes[blockCounter] = new List<string>();   <br />
                            }<br />
<br />
                        }<br />
                    }<br />
<br />
<br />

Why are you converting byte values to strings to test for numeric equality? Just test against the decimal or hex value.

And please use <pre></pre> tags not <code></code> to surround your code blocks; that is why the button is called "code block".

Just say 'NO' to evaluated arguments for diadic functions! Ash

Hi,

your code is hard to read, you should use PRE tags instead of CODE tags, as that would preserve formatting and indentation.
You also should HTML-escape the < and > and & signs, possibly using the widgets the edit page offers. That way the generic lists would show properly. You could still edit and improve the existing message.

Here are some comments:

1.
When the data is numeric, it is just silly to convert it to string for comparison purposes. You really should be using something like

if (myIntOrMyByte==0x55)...

and not mix decimal and hexadecimal all the time. C# knows about hex literals!

2.
Is this an official standard you're implementing? I'm not familiar with double 0x55 and double 0xCC as special markers. And what makes one so sure they will never appear in the data?

3.
If you're getting exceptions, you should watch the stack traceback; for a debug build it holds class names, file names *and* line numbers, pointing to the exact line that bombs. And if you can't figure it out, show the exact exception message and indicate the line where it happens.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Season's Greetings to all CPians.

What exceptions are you receiving? If you could elaborate it may help get the root of the problem.

"Simplicity carried to the extreme becomes elegance."
-Jon Franklin

when I have block start with 55 55 but not content any message and end with with 204 204

like this
55 55 1C 09 0A 0C

CC CC

and like those

55 55 1B 0B 0A 17 99 1E 3F 48 56 41 30 35 31 30
32 36 4E 4E 20 20 30 35 30 20 20 20 20 01 00 32
1E F4 D5 0D CC CC 55 55 1B 0B 0B 04 CC CC

99 0A 41 2F 02 08 78 03 00 0D

CC CC

Yes that's fine.
But what error message or exception do you get?
Or do you not get an error where you expected one?

If you won't help us, we can't help you.

What is the error?

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Let me get this straight, because I think there are language barriers here. In reference to your example data... a 'BLOCK' is considered everything between 0x55 and 0xCC right? If this is the case, then a couple of your example data sets have multiple blocks. Luc is right in his previous post that data has to escape the fencepost identifiers if they appear inside the payload. And the issue is that your dividing into BLOCKS is not working as expected? No exceptions, just not valid results, ya?

"Simplicity carried to the extreme becomes elegance."
-Jon Franklin

1) The first 'for' loop does not use its indexer. You can easily change the 'for' loop to a 'foreach' loop and iterate through the bytes. This will simplify your code a little.

2) Do comparisons of bytes, don't convert to strings.

3) If you're working in hex numbers use hex numbers throughout your code, don't mix up number bases. This will make your code easier to understand.

4) Your logical comparisons should use the logical && operator and not the & operator. The & operator returns a bitwise operation resulting in a number, not true or false. They are VERY different.

5) You should always put magic numbers in your code as constants.

public const Byte StartDelimiter = 0x55;

You should never sprinkle those into code manually, you run a huge risk if you are forced to refactor your work. Not to mention that you may mistype one.

6) I would avoid doing tricks with your loop variable like incrementing/decrementing it inside your loop block unless it is absolutely necessary - which should be never.

7) Match your braces. Just because you don't necessarily have to put them in after an 'if' statement doesn't mean you shouldn't. IMHO.

8) Do yourself a favor and look up the State Machine design pattern, it works very well for these kinds of problems.

9) When I ran your program (with healthy fixups) I found that you presumed that every 0xCC,0xCC was an end delimiter. This, apparently, is a false presumption. CCCC appears in your third dataset as valid information, and should not be treated as a fencepost delimiter. fix that up and I think you should get valid results, or at least get you further along.

Regards,

"Simplicity carried to the extreme becomes elegance."
-Jon Franklin

This is one of the best, and most thorough answers I have ever read, and I agree with every bit of it. I even learned a bit. Thanks! Big Grin | :-D

Will Rogers never met me.

Hi ,

Is there a way to change the table name of a datatable in a dataset or create a new dataset and copy the table with a new name in to the new dataset?

Jack Sparrow
--------------------------------------
Defeat is not the worst of failures. Not to have tried is the true failure.

Use below code and next time try to use Google

dataset.Tables[0].TableName = "MyTable1"; 
dataset.Tables[1].TableName = "MyTable2";

or do it in loop

for (int i = 0; i <= dataset.Tables.Count; i++) 
{

dataset.Tables[i].TableName = "MyTable" + i.ToString(); 
}

Cheers,
SMP

Recent Tip/Tricks

Prevent a drag and drop text and Copy paste text in your textbox control

Find a column name within SQL database

Thanks mate, really not sure how I missed this...

Jack Sparrow
--------------------------------------
Defeat is not the worst of failures. Not to have tried is the true failure.

you are welcome Smile | :)

Cheers,
SMP

Recent Tip/Tricks

Prevent a drag and drop text and Copy paste text in your textbox control

Find a column name within SQL database

Here is the error:

System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

I receive this after ~32 seconds of running a SqlCommand. Now, normally the default timeout is 30 seconds, but I have increased this up to 10 minutes and still the timeout happens in 30 seconds. The connection string says Timeout=600 and I do not override this anywhere in the code. In fact, I can print the timeout prior to running the query and it says 600.

Am I missing something obvious here?

There are two different time outs for SQLConnection and SQLCommand.
Set longer timeout to the SqlCommand object (30 is default).
I hope if this helps Smile | :)

Also,
While declaring the command object set the timeout property 0 i.e. infinity.

SqlCommand cmd = new SqlCommand();
cmd.CommandTimeout=0;

Try this! Smile | :)

Very clever that you reply twice so I can give you two 5's Laugh | :laugh:

Answer is very much appreciated (with small modification)!

SqlCommand cmd = new SqlCommand();
cmd.CommandTimeout=con.ConnectionTimeout;

Now I can still modify the timeout just from the config file's connection string.

yes, dats better to keep config in scene!

i was in hurry to head towards home, so just didnt modify and took a new message post instead Smile | :)