C# Discussion Boards - CodeProject

RizwanSharp3-Aug-06 19:32

3-Aug-06 19:32

Yes,
I have tried all the things, I set all the panels and all oher controls' TabStop property to false.
But again the same proble.
When I run the application, The focus of the control must be at the control whose TabIndex is 0 rather it focuses control with TabIndex 2.

When I try check CanFocus property of Controls with TabIndex 0 in Form's Load it returns false.

I want to know the reason what's the reason behind "Control.CanFocus is always false". How does it evaluate this that it cannot be focused. If i know this then may be we can solve the problem.

Thanks alot,
Best Regards,
Rizwan Ahmed.

connection question

skyeddie3-Aug-06 6:01

skyeddie

3-Aug-06 6:01

hi all i have this pro on hand now.. i have downloaded some sample database applications from the internet..however when i want to debug it i gives me the error--An unhandled exception of type "system.Data.OleDb.OledbException" occurred in system.data.dll

does this errors occur due to where the dB file is located..is it correct? can someone out there help will this pro? and maybe guide me to correcting it ..thanks in advance..

an extract on of codes where the problem is highlighted is below:the pro is bold...thanks in advance

private void fclsMain_Load(object sender, System.EventArgs e)
{
m_cnADONewConnection.ConnectionString =
@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\temp\contacts.mdb";
m_daDataAdapter =
new OleDbDataAdapter("Select * From Contacts",m_cnADONewConnection);
OleDbCommandBuilder m_cbCommandBuilder = new OleDbCommandBuilder(m_daDataAdapter);
m_daDataAdapter.Fill(m_dtContacts);
this.ShowCurrentRecord();

Re: connection question

Rob Graham3-Aug-06 6:17

Rob Graham

3-Aug-06 6:17

You need
cnADONewConnection.Open();
before
m_daDataAdapter.Fill(m_dtContacts);

Re: connection question

Not Active3-Aug-06 7:32

Not Active

3-Aug-06 7:32

DataAdapter handles the open and close connection in the Fill method

only two letters away from being an asset

Re: connection question

Not Active3-Aug-06 7:33

Not Active

3-Aug-06 7:33

What is the message in the exception? This will tell you (and us) more of what is going on.

only two letters away from being an asset

hi, [modified]

Sunny H3-Aug-06 6:00

Sunny H

3-Aug-06 6:00

Here is my problem
I want to print the contents of the datagrid c# in ASP.NET 2.0 but the constraints are:
1>When the user clicks the print button all the records till the end even the data is not visible to the user should get print.
2>It should print according to the page size that is the user tells how many records has to be dispalyed at a time on a webpage.
3>At every page the page header and footer sholud be displayed defined by the user
4>How to access the page footer and header programatically inorder to avoid to print the url at the end of the page.

Does any one knows the solution please reply it's urgent!

sunny

Re: hi,

Ingo3-Aug-06 6:33

Ingo

3-Aug-06 6:33

Hi,

you are in the wrong board. ASP.NET Question should be asked in ASP.NET Board. Secondly you just use a subject that is corresponding to the problem and not just "hi". Use a subject as: "Printing a datagrid"

I can't help you, as I don't have an active ASP project and my last one was mutiple month ago.

Regards,
Ingo

------------------------------
PROST Roleplaying Game

War doesn't determine who's right. War determines who's left.

How can I run an executable from within my C# app

sas94913-Aug-06 5:32

sas9491

3-Aug-06 5:32

I need to run zip a file(s) using winzip from within my c# application. Can anyone point me to documentation / example of how to accomplish that. Thanks in advance - SS -

Re: How can I run an executable from within my C# app

Not Active3-Aug-06 5:42

Not Active

3-Aug-06 5:42

Process.Start[^]

only two letters away from being an asset

Use Rar

Ennis Ray Lynch, Jr.3-Aug-06 5:45

Ennis Ray Lynch, Jr.

3-Aug-06 5:45

Then include the J# libraries and you can do it programmatically.

A man said to the universe:
"Sir I exist!"
"However," replied the Universe, "The fact has not created in me A sense of obligation."

-- Stephen Crane

Re: How can I run an executable from within my C# app

Dustin Metzgar3-Aug-06 5:54

Dustin Metzgar

3-Aug-06 5:54

Why zip with winzip when you can do it in code: SharpZipLib[^]

Logifusion[^]
If not entertaining, write your Congressman.

XML Question [modified]

SoftcodeSoftware3-Aug-06 5:18

SoftcodeSoftware

3-Aug-06 5:18

If I have an xml file such as below:

<printItAll>
<chatMessage>
<xml1>username</xml1>
<xml2>message here!</xml2>
<xml3>red</xml3>
<xml4>arial</xml4>
<msgID>3</msgID>
</chatMessage>
<chatMessage>
<xml1>Ben Griffiths</xml1>
<xml2>some random message</xml2>
<xml3>red</xml3>
<xml4>arial</xml4>
<msgID>4</msgID>
</chatMessage>
</printItAll>

How would I count the <chatMessage> elements, and how could I loop through them? At the moment my file only reads the first one. Here is my current code:

XmlDocument xDoc = new XmlDocument();
xDoc.Load("my_xml_file.xml");
XmlNodeList xml1 = xDoc.GetElementsByTagName("xml1");
XmlNodeList xml2 = xDoc.GetElementsByTagName("xml2");
XmlNodeList xml5 = xDoc.GetElementsByTagName("msgID");
string chat_memberU = (xml1[0].InnerText + ": ");
string chat_message = (xml2[0].InnerText);
int latestID = Int32.Parse(xml5[0].InnerText);

Many thanks, Ben.

-- modified at 11:19 Thursday 3rd August, 2006

Re: XML Question

Stefan Troschuetz3-Aug-06 5:28

Stefan Troschuetz

3-Aug-06 5:28

SoftcodeSoftware wrote:
count the <chatmessage> elements

Retrieve the Count property of one of the XmlNodeLists.

SoftcodeSoftware wrote:
how could I loop through them?

Iterate over the XmlNodeLists you've already got.

"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rick Cook

www.troschuetz.de

Re: XML Question

SoftcodeSoftware3-Aug-06 5:38

SoftcodeSoftware

3-Aug-06 5:38

Hi, thanks,

I actually realized it was in an array just now lol, got it working Smile | :)

interupting the loop with the button [modified]

Blubbo3-Aug-06 5:00

Blubbo

3-Aug-06 5:00

I have a code that monitors the electrical loop. Once the button is pressed, it would loop until the button is pressed. The problem is that when the code loops (I use while loop), the button cannot be pressed and the programs acts like as if it is locked up. How do I get the program check for any event while looping? Like for example, in borland c++, it uses "Application->ProcessMessages()".

How do I apply this to Visual Studio.NET?

Unsure | :~

-- modified at 11:16 Thursday 3rd August, 2006

Code sample below:

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Threading;

namespace loop_test
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.NumericUpDown numUpDn;
private System.Windows.Forms.Button btnLoop;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;

public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
this.btnLoop.BackColor = System.Drawing.Color.Red;
}

/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.btnLoop = new System.Windows.Forms.Button();
this.numUpDn = new System.Windows.Forms.NumericUpDown();
((System.ComponentModel.ISupportInitialize)(this.numUpDn)).BeginInit();
this.SuspendLayout();
//
// btnLoop
//
this.btnLoop.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
this.btnLoop.Location = new System.Drawing.Point(56, 16);
this.btnLoop.Name = "btnLoop";
this.btnLoop.Size = new System.Drawing.Size(176, 96);
this.btnLoop.TabIndex = 0;
this.btnLoop.Text = "Loop Stopped";
this.btnLoop.Click += new System.EventHandler(this.btnLoop_Click);
this.btnLoop.BackColorChanged += new System.EventHandler(this.btnLoop_BackColorChanged);
//
// numUpDn
//
this.numUpDn.Location = new System.Drawing.Point(72, 136);
this.numUpDn.Name = "numUpDn";
this.numUpDn.TabIndex = 3;
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 174);
this.Controls.Add(this.numUpDn);
this.Controls.Add(this.btnLoop);
this.Name = "Form1";
this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
this.Text = "Loop interruption Test";
((System.ComponentModel.ISupportInitialize)(this.numUpDn)).EndInit();
this.ResumeLayout(false);

}
#endregion

/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}

private void btnLoop_Click(object sender, System.EventArgs e)
{
if (this.btnLoop.BackColor == System.Drawing.Color.Red)
this.btnLoop.BackColor = System.Drawing.Color.Lime;
else
this.btnLoop.BackColor = System.Drawing.Color.Red;

}

private void btnLoop_BackColorChanged(object sender, System.EventArgs e)
{
while (this.btnLoop.BackColor == System.Drawing.Color.Lime)
{
this.numUpDn.Value += 1;
this.numUpDn.Update();
Thread.Sleep(500);
}
}
}
}

Re: interupting the loop with the button

User 66583-Aug-06 5:09

User 6658

3-Aug-06 5:09

Can't you just use a seperate thread for your loop?

modified 12-Sep-18 21:01pm.

Re: interupting the loop with the button

Not Active3-Aug-06 5:14

Not Active

3-Aug-06 5:14

Use a seperate processing thread and a ManualResetEvent to trigger the stop/start

only two letters away from being an asset

Re: interupting the loop with the button

Stefan Troschuetz3-Aug-06 5:21

Stefan Troschuetz

3-Aug-06 5:21

The method you're looking for is Application.DoEvents.
Nevertheless I also think it would be a much nicer way to do the loop inside of a separate thread.

Re: interupting the loop with the button

Blubbo3-Aug-06 5:26

Blubbo

3-Aug-06 5:26

Yeah... seems that "Application.DoEvents()" in the while loop does the trick. Thanks!

Re: interupting the loop with the button

Nader Elshehabi3-Aug-06 5:31

Nader Elshehabi

3-Aug-06 5:31

Hello

There is a method that do the same thing as ProcessMessages in C#, it's called Application.DoEvent(). So it process all the messages in your queue including the Button.Click

Here is a simple class that will do what you wany. Note that Button1 starts the loop. Button2 ends it:

public partial class Form1 : Form
    {
        bool Go;
        public Form1()
        {
            InitializeComponent();
            Go = true;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Go = true;
            int temp = 0;
            textBox1.Text = "0";
            while (Go)
            {
                temp++;
                textBox1.Text = temp.ToString();
                button1.Capture = false;  //This is present only in .NET 2.0
                Application.DoEvents();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Go = false;
        }
    }

Regards

Asynchronous socket question

Madmaximus3-Aug-06 4:39

Madmaximus

3-Aug-06 4:39

Hi all,

I have a continuous stream of packet data going through my asynchronous socket connection. My question is how can I tell in the EndReceive callback method where one package of data ends and another begins? I coded the socket class in C# 1.1.

Thanks in an advance. Smile | :)

Ken

Re: Asynchronous socket question

Tim Kohler3-Aug-06 5:56

Tim Kohler

3-Aug-06 5:56

You have to have a delimiter in the data. And once you read in the delimiter in the callback, you'll know you got to the end of one message/stream and you're now reading for the next message/stream.

So a very simple protocol is needed to delimit your messages. You have to make sure you read all the message as it may/may not (certainly not guaranteed) to be send in a single socket.send.

Prefix

Ennis Ray Lynch, Jr.3-Aug-06 5:59

Ennis Ray Lynch, Jr.

3-Aug-06 5:59

I like to prefix my messages with a length rather than delimit them.

A man said to the universe:
"Sir I exist!"
"However," replied the Universe, "The fact has not created in me A sense of obligation."

-- Stephen Crane

Re: Asynchronous socket question

RizwanSharp3-Aug-06 6:11

RizwanSharp

3-Aug-06 6:11

The more appealing and real world solution for all types of data transfer is to prefix each messaeg with its length.

Procedure is as follow.

Sending Part:

1) Calculate the Number of bytes produced by a message.
2) Store length as an integer value.
3) Convert the Length (integer) into bytes using BitConverter.GetBytes(messageLength) method.
4) Send these bytes on stream.
5) Send the original message.

Receiving Part:

1) Read 4 bytes from the stream Asynchronously.
2) Convert these bytes into integer value using BitConverter.ToInt32(buffer,0)
3) Now creat a Memory Stream and loop on it untill that message size is met.

Its the best technique in my knowledge and supports in Network delay situation for other type of data (Not String)

If you have further queries, feel free to conact me Wink | ;)

rizwansharp@hotmail.com

Best Regards,
Rizwan

Impersonation + Process.Start

Gonzalo Brusella3-Aug-06 4:12

Gonzalo Brusella

3-Aug-06 4:12

I have to run several secuential proceses, some of them impersonated from the main identity of the program.

Using .Net 2.0, the a "ProcessStartInfo" instance, can impersonate, but the password must be a "SecureString".

I have the Username and the Password on a encrypted file, but when I decrypt the tye file, password this make is readable (wich we all know is bad thing).

The constructor of "SecureString", does not take a String as parameter, so I mahe this (check the sample):

System.Diagnostics.ProcessStartInfo _ps = new System.Diagnostics.ProcessStartInfo();

_ps.FileName = _command;
_ps.CreateNoWindow = false;
_ps.Arguments = _arguments;
_ps.UseShellExecute = false;

//Load the SecureString (This can be worst way)
SecureString _psw = new SecureString();

string _password = "123456";
foreach (char Character in _password.ToCharArray())
{
    _psw.AppendChar(Character);
}

_psw.MakeReadOnly();

_ps.LoadUserProfile = false;
_ps.UserName = "User";
_ps.Password = _psw;

System.Diagnostics.Process _process = new System.Diagnostics.Process();
_process.Start(_ps);
_process.WaitForExit();

Now There is way to solve the clear-password-in-memory problem?

The user account is a restricted account, but with access to some processes wich we don't want to be publicaly accessed.

I'm on a Fuzzy State: Between 0 an 1

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