String implementation in .NET Framework - C# Discussion Boards

Re: C# Enterprise Projects - Practical examples

4-Nov-08 5:45

Sadly the books are poor guidelines and this is a massive topic that most sources seem to glaze over the important parts or down-right neglect them. The only free advice I can give that will fit within a post is:

1) Keep it simple
2) Keep it compartmentalized
3) Don't use session (or caching)
4) Load the least amount of data possible
5) Optimize last

Need software developed? Offering C# development all over the United States, ERL GLOBAL, Inc is the only call you will have to make.

Happiness in intelligent people is the rarest thing I know. -- Ernest Hemingway

Most of this sig is for Google, not ego.

Meer Osman Ali4-Nov-08 5:50

Meer Osman Ali

4-Nov-08 5:50

The word "big" is generally relative. I believe there are several projects in codeproject which certify enough to be called maintainable, scalable etc. Never trust examples in books because they are generally meant for beginners. Instead why don't you go thru cp articles?

Reg:email domain Verification

swethasri4-Nov-08 4:07

swethasri

4-Nov-08 4:07

Hi all,
I want to check the email address against SMTP domain verification. I have used the following code.but it's not getting the response from the domains gmail.com,yahoo.com,google .com. so it shows that domain is not valid.

try
{
string[] host = (textBox1.Text.Trim().Split('@'));
string hostname = host[1];

IPHostEntry IPhst = Dns.GetHostByName (hostname);
IPEndPoint endPt = new IPEndPoint(IPhst.AddressList[0], 25);
Socket s = new Socket(endPt.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
s.Connect(endPt);
MessageBox.Show("Exists");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString ());
}

Can anyone tell me the solution for this.

Thanks in advance
swethasri

Re: Reg:email domain Verification

Ennis Ray Lynch, Jr.4-Nov-08 4:20

Re: Reg:email domain Verification

4-Nov-08 4:20

What kind of error are you getting.

swethasri4-Nov-08 5:17

swethasri

4-Nov-08 5:17

The following is the message displayed when tried to check gamil.com,yahoo.com etc.,

"A connection attempt failed because the connected party did not respond propertly after a period of time or established connection failed because connected host failed to respond".

Re: Reg:email domain Verification

Guffa4-Nov-08 12:36

Guffa

4-Nov-08 12:36

I think that those SMTP servers only accept connections from known mail servers.

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

String implementation in .NET Framework

J4amieC4-Nov-08 3:38

4-Nov-08 3:38

I have some legacy VB6 code which im converting over to C#, and it seems that strings were implemented very differently in old VB than in the Framework. I get vastly different results from the ported code than I do from an app written in VB and I was wondering if anyone could put their finger on the reason why?

here is the old VB code (pstrResponse is the input to the method):

For i = 1 To Len(pstrResponse)

      j = Asc(Mid(pstrResponse, i, 1))

      If j > 127 Then

         j = j - 128

         Mid(pstrResponse, i, 1) = Chr(j)

      End If

   Next i

Here is my ported C# (input is the input):

char[] charArray = input.ToCharArray();
int bit;
for (int i = 0; i < charArray.Length; i++)
{
    bit = (int)charArray[i];
    if (bit > 127)
    {
        bit -= 128;
        charArray[i] = (char)bit;
    }
}
return new string(charArray);

As you can see, simple code & easy to port but very different results. Any ideas people?

Ennis Ray Lynch, Jr.4-Nov-08 4:06

4-Nov-08 4:06

.NET stores string in Unicode not Ascii and a char is 2 bytes not one I think? Which would mean the -=128 could have a different value in an integer data type?
I don't really know I am just speculating.

J4amieC4-Nov-08 4:12

4-Nov-08 4:12

Ennis Ray Lynch, Jr. wrote:
Which would mean the -=128 could have a different value in an integer data type

Any idea what it could be?

Ennis Ray Lynch, Jr.4-Nov-08 4:18

4-Nov-08 4:18

Maybe, Asc(Mid(pstrResponse, i, 1)) != (int)characters[i];

Try using the System.Text.AsciiEncoder to change the string by ascii bytes only first and see what happens?

J4amieC4-Nov-08 5:25

4-Nov-08 5:25

Thanks for the pointers. With your help ive managed to solve the problem, but strangly enough I thought id need to convert my input to ASCII using ASCIIEncoding.GetBytes. In actual fact I had to use DefaultEncoding.GetBytes to get the result I was expecting. Confused | :confused:

here's the working code now:

byte[] byteArray = Encoding.Default.GetBytes(input);

StringBuilder sb = new StringBuilder(byteArray.Length);
byte bit;
for (int i = 0; i < byteArray.Length; i++)
{
    bit = (byte)byteArray[i];
    if (bit > 127)
    {
        bit -= 128;
    }
    sb.Append((char)bit);
}
return sb.ToString();

Thanks again for your help.

DaveyM694-Nov-08 4:32

DaveyM69

4-Nov-08 4:32

Apparently this still exists in the Microsoft.VisualBasic namespace.

This is the Asc function after being run through reflector - it seems to work OK.

public static int Asc(char theChar)
{
    int num;
    int num2 = Convert.ToInt32(theChar);
    if (num2 < 0x80)
    {
        return num2;
    }
    try
    {
        byte[] buffer;
        Encoding fileIOEncoding = Encoding.Default;
        char[] chars = new char[] { theChar };
        if (fileIOEncoding.IsSingleByte)
        {
            buffer = new byte[1];
            int num3 = fileIOEncoding.GetBytes(chars, 0, 1, buffer,
            0);
            return buffer[0];
        }
        buffer = new byte[2];
        if (fileIOEncoding.GetBytes(chars, 0, 1, buffer, 0) == 1)
        {
            return buffer[0];
        }
        if (BitConverter.IsLittleEndian)
        {
            byte num4 = buffer[0];
            buffer[0] = buffer[1];
            buffer[1] = num4;
        }
        num = BitConverter.ToInt16(buffer, 0);
    }
    catch (Exception exception)
    {
        throw exception;
    }
    return num;
}

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

J4amieC4-Nov-08 5:26

4-Nov-08 5:26

Yeah, I saw that but I was attempting to avoid the use of nasty VB namespaces Dead | X|

DaveyM694-Nov-08 5:32

DaveyM69

4-Nov-08 5:32

J4amieC wrote:
nasty VB

If you use the code above you don't need to - it's just that function converted to C#

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

PIEBALDconsult4-Nov-08 4:34

PIEBALDconsult

4-Nov-08 4:34

J4amieC wrote:
As you can see, simple code & easy to port but very different results

No, I can't see; what are the results?

Provided you don't care about Unicode, you could use:

System.Text.Encoding.ASCII.GetBytes()

and

System.Text.Encoding.ASCII.GetString()

You could also access the characters in an unsafe context much like your VB code. Something like:

private unsafe static void
ASCIIize
(
    string Subject
)
{
    fixed ( char* subject = Subject )
    {
        int* length = (int*) subject - 1 ;
        int  index  = 0 ;
 
        while ( index < *length )
        {
            *(subject + index) &= (char) 0x7F ;
 
            index++ ;
        }
    }
 
    return ;
}

(Though I haven't tested this with the problematic characters.)

J4amieC4-Nov-08 5:28