C# Discussion Boards - CodeProject

Re: urgent help pleasse [image processing , pointers , byte ]

10-Jun-09 6:31

WinSolution wrote:
this is not working when i execute my prject

What does this mean?
Are you getting an exception?
Does it do something you do not expect?
Have you single stepped, to see what value div is set to in your code?

What, which, something else?

BTW there are several articles here on CP that demonstrate converting to greyscale, have you looked at them.

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.”

WinSolution10-Jun-09 6:38

WinSolution

10-Jun-09 6:38

Thanks both

problem solved i was not handling exception and not i placed that code outside of the loops as follow

public Bitmap GrayScale(Bitmap bmpimg)
{
BitmapData bmpData = bmpimg.LockBits(new Rectangle(0, 0, bmpimg.Width, bmpimg.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
int remain = bmpData.Stride - bmpData.Width * 3;

unsafe
{
byte* ptr = (byte*)bmpData.Scan0;
int div = 1;
try
{
div = Convert.ToInt32(textBox1.Text.Trim());
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
for (int i = 0; i < bmpData.Height; i++)
{
for (int j = 0; j < bmpData.Width; j++)
{

ptr[0] = ptr[1] = ptr[2] = (byte)((ptr[0] + ptr[1] + ptr[2]) / div);

ptr += 3;
}
ptr += remain;
}
}

bmpimg.UnlockBits(bmpData);

return bmpimg;
}

Re: urgent help pleasse [image processing , pointers , byte ]

Luc Pattyn10-Jun-09 7:29

Luc Pattyn

10-Jun-09 7:29

Hi,

when you store the value of bmpData.Width in a local variable, your code will run some 20% faster.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.

Re: urgent help pleasse [image processing , pointers , byte ]

Christian Graus10-Jun-09 8:46

Christian Graus

10-Jun-09 8:46

WinSolution wrote:
div = Convert.ToInt32(textBox1.Text.Trim());

You should use int.TryParse to test if the entered text is a number or not.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

Re: urgent help pleasse [image processing , pointers , byte ]

saurabh sahay10-Jun-09 11:50

saurabh sahay

10-Jun-09 11:50

You may also handle the exception for ptr[0] = ptr[1] = ptr[2] = (byte)((ptr[0] + ptr[1] + ptr[2]) / div);

HttpResponse Compression... ?

Trapper-Hell10-Jun-09 5:54

Trapper-Hell

10-Jun-09 5:54

[Intro]

To keep the story short, I have created a Download manager creating various simultaneous HttpRequests and downloading the HttpResponses (of the files).

In brief, the relevant code looks somewhat like this...

dRequest = (HttpWebRequest)WebRequest.Create(txtURL.Text);
dRequest.AddRange(dFrom, dTo);
dResponse = (HttpWebResponse)dRequest.GetResponse();
Stream dStream = dResponse.GetResponseStream();

..And of course the download is saved etc etc etc. This all works fine.

[End of Intro]

Today I was told that I should enable compression (from the server side - whenever possible) when downloading the file in order to speed up the download even more... However, I have no idea how this works or how this can be achieved?

I am not asking for someone to do the code for me (although any examples are appreciated), but I would like to know how this can be achieved / how the system works, or what to search for, in order to achieve this?

Huge thanks! Big Grin | :-D

Colin Angus Mackay10-Jun-09 6:15

Colin Angus Mackay

10-Jun-09 6:15

Trapper-Hell wrote:
Today I was told that I should enable compression (from the server side - whenever possible) when downloading the file in order to speed up the download even more... However, I have no idea how this works or how this can be achieved?

Isn't it a setting in IIS?

http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/d52ff289-94d3-4085-bc4e-24eb4f312e0e.mspx?mfr=true[^]

Man who stand on hill with mouth open wait long time for roast duck to drop in

saurabh sahay10-Jun-09 6:18

saurabh sahay

10-Jun-09 6:18

Please go through the following article which contains exactly what you need

Using HTTP Compression for Faster Downloads[^]

If you need to increase the speed further then you may use the below code which actually deals in sockets and increases the speed to many folds when parallel downloading is going on.

public class MyWebResponse
{
public MyWebResponse()
{
}
public void Connect(MyWebRequest request)
{
ResponseUri = request.RequestUri;

socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPEndPoint remoteEP = new IPEndPoint(Dns.Resolve(ResponseUri.Host).AddressList[0], ResponseUri.Port);
socket.Connect(remoteEP);
}
public void SendRequest(MyWebRequest request)
{
ResponseUri = request.RequestUri;

request.Header = request.Method + " " + ResponseUri.PathAndQuery + " HTTP/1.0\r\n" + request.Headers;
socket.Send(Encoding.ASCII.GetBytes(request.Header));
}
public void SetTimeout(int Timeout)
{
socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.SendTimeout, Timeout * 1000);
socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, Timeout * 1000);
}
public void ReceiveHeader()
{
Header = "";
Headers = new WebHeaderCollection();

byte[] bytes = new byte[10];
while (socket.Receive(bytes, 0, 1, SocketFlags.None) > 0)
{
Header += Encoding.ASCII.GetString(bytes, 0, 1);
if (bytes[0] == '\n' && Header.EndsWith("\r\n\r\n"))
break;
}
MatchCollection matches = new Regex("[^\r\n]+").Matches(Header.TrimEnd('\r', '\n'));
for (int n = 1; n < matches.Count; n++)
{
string[] strItem = matches[n].Value.Split(new char[] { ':' }, 2);
if (strItem.Length > 0)
Headers[strItem[0].Trim()] = strItem[1].Trim();
}
// check if the page should be transfered to another location
if (matches.Count > 0 && (
matches[0].Value.IndexOf(" 302 ") != -1 ||
matches[0].Value.IndexOf(" 301 ") != -1))
// check if the new location is sent in the "location" header
if (Headers["Location"] != null)
{
try { ResponseUri = new Uri(Headers["Location"]); }
catch { ResponseUri = new Uri(ResponseUri, Headers["Location"]); }
}
ContentType = Headers["Content-Type"];
if (Headers["Content-Length"] != null)
ContentLength = int.Parse(Headers["Content-Length"]);
KeepAlive = (Headers["Connection"] != null && Headers["Connection"].ToLower() == "keep-alive") ||
(Headers["Proxy-Connection"] != null && Headers["Proxy-Connection"].ToLower() == "keep-alive");
}
public void Close()
{
socket.Close();
}
public Uri ResponseUri;
public string ContentType;
public int ContentLength;
public WebHeaderCollection Headers;
public string Header;
public Socket socket;
public bool KeepAlive;
}

2)

Trapper-Hell10-Jun-09 6:25

Trapper-Hell

10-Jun-09 6:25

Thanks mate! It appears to be just what I wanted... Looks more complex then the methods I'm currently using but I guess that's the way to go... Thanks a lot Wink | ;)

Extracting Repeating Table Data In a Web Part

saurabh sahay10-Jun-09 6:35

saurabh sahay

10-Jun-09 6:35

You welcome buddy Smile | :)

lday8610-Jun-09 5:42

lday86

10-Jun-09 5:42

Hi,

I am pretty new to developing in InfoPath and SharePoint. I have the requirement to extract repeating table data from an InfoPath form using web part (written in C#).

I have been looking into how I might go about doing this but I don't seem to have come up with a solution.

I have tried getting the document as an XML document but it will not let me open it in the web part and claims I don't have the correct permissions, even though i have full permissions across the whole site (including on the document library)

Could anyone point me in the right direction or offer any advice?

Many thanks in advance,
Luke

changing the color and text of the label control dynamically from the retrieved values from the database

praveenkumar_vittaboina10-Jun-09 4:58

praveenkumar_vittaboina

10-Jun-09 4:58

For a label control i dynmically changed the font and color of the text and then i stored those values in the database(access) and i want to apply the values stored in the database to other labels. How to apply those stored values to other labels from the database. I retrieved those values from database i got the values as string , then how to apply these string values to change the color of the label.

Re: changing the color and text of the label control dynamically from the retrieved values from the database

Tom Deketelaere10-Jun-09 5:22

Tom Deketelaere

10-Jun-09 5:22

praveenkumar_vittaboina wrote:
i got the values as string

Storing colors should result into a numeric value.

look at the 'color.toargb' and 'color.fromargb' functions.
Or 'color.toknowncolor' and 'color.fromknowncolor' functions

crystal reports problem after installing the application.

praveenkumar_vittaboina10-Jun-09 4:57

praveenkumar_vittaboina

10-Jun-09 4:57

the project which i am doing is windows based project . In that i need to generate some reports , so i did that with crystal reports and then i created a setup file and then i installed in another system, then i am getting the exception . After that i removed crystal reports from my project and again i installed the setup file , then its working fine. I want to know how to include the reports.

Re: crystal reports problem after installing the application.

Tom Deketelaere10-Jun-09 5:19

Tom Deketelaere

10-Jun-09 5:19

Without knowing more about the error you get I think you need to install the crystal report framework.
You can include this into your .net setup.
Google for merge modules on how to do that.
The crystal reports site has the download for their merge modules somewhere but I can't find the link right now.

Checking a registry key exists

Martin3108810-Jun-09 4:21

10-Jun-09 4:21

Hi everyone,

I'm writing a little application and I've hit a bit of a problem.

part of the program uses the registry to store certain things. I have no problem writing or reading a key. But I need to be able to check the key exists, if it does do this, if not write the key.

Here's the code I'm currently using:

using Microsoft.Win32;<br />
RegistryKey MyRegKey = Registry.LocalMachine.OpenSubKey("software\\MyApp\\SaveData");<br />
            if (MyRegKey != null)<br />
            {<br />
                string OptCurrency = MyRegKey .GetValue("Currency").ToString();<br />
            }<br />
            else<br />
            {<br />
                RegistryKey CreateMyRegKey = Registry.LocalMachine.CreateSubKey("software\\MyApp\\SaveData");<br />
                CreateMyRegKey .SetValue("Currency", 0);<br />
                string OptCurrency = "0";<br />
            }<br />
MyRegKey.Close();

This is fine if the key exists, but doesn't recognise if it does not, and runs through the if rather than the else.

Any help would be greatly appreciated
Many thanks
Martin

Henry Minute10-Jun-09 4:45

10-Jun-09 4:45

I am not sure that I understand this.
Are you saying that if software\\MyApp\\SaveData doesn't exist, the if part of your code executes?

BTW: if you surround your code snippet with <pre></pre>, rather than <code></code>, it will allow you to retain the formatting and make it easier for others to read. (use the 'code block' widget, not the 'inline code' one).

Martin3108810-Jun-09 4:57

10-Jun-09 4:57

the other way around, if that key doesn't exist run the else part to create the key.

Henry Minute10-Jun-09 5:07

10-Jun-09 5:07

I realise that is what you intend to happen. But your OP indicated the reverse.

This is fine if the key exists, but doesn't recognise if it does not, and runs through the if rather than the else.

indicates to me that the if block gets executed regardless of whether the key exists or not.

Perhaps you might try rewording your question, to differentiate what you want to happen from what currently happens.

Martin3108810-Jun-09 5:35

10-Jun-09 5:35

Currently
It does run through the if regardless of whether the key exists or not. The way the code is at the moment (some changes have been made to the previous post) the key will get created if it does not exist. I can then make a change in the options of my application and apply them which saves the change to their respective keys.

Then when I close the program and re-open it, the keys are reset back to the default because the code is running through the wrong part of my if statement and overwriting the key.

Intended
I would like it to be able to tell if the key exists, if it does not, create it, if it does, copy the value of each key into the defined global variables. So that program can use these values wherever necessary.

I'll post the altered code if you need.
I hope this clears it up.
Thanks

Henry Minute10-Jun-09 6:16

10-Jun-09 6:16

I do not use the registry any more, or very rarely, so I have had to go back and look at some of my old code.

The only obviously different things that I used to do is as below.

string myAppSaveDataSubKey = @"software\MyApp\SaveData"; <=== use a variable. saves having to keep typing it in and possible typos
using (RegistryKey MyRegKey = Registry.LocalMachine.OpenSubKey(myAppSaveDataSubKey)) <== using 'using' saves having to remember 'close'
{
    if (MyRegKey == null)  <=========== Check == null instead of != null
    {
        RegistryKey CreateMyRegKey = Registry.LocalMachine.CreateSubKey(myAppSaveDataSubKey);
        CreateMyRegKey.SetValue("Currency", 0);
        string OptCurrency = "0";
    }
    else
    {
        string OptCurrency = MyRegKey.GetValue("Currency").ToString(); <== you need to load OptCurrency anyway so don't 'else' it
    }
}

which used to work OK for me.

The only other thing you might consider is to use CreateSubKey instead of OpenSubKey. This has the advantage of creating the subkey if it doesn't exist, and simply opening it for writing if it does.

Hope some of this is useful. Smile | :)

Martin3108810-Jun-09 6:28

10-Jun-09 6:28

Thanks for the suggestion, I'll have to look at it tomorrow.

I'll let you know how I get on.

Thanks alot for your support
Martin

Martin3108810-Jun-09 23:57