File Not Found Exception Handling - C# Discussion Boards

Re: Desktop Calender Repost

1-Mar-09 6:27

Then what you may want is to create a gadget for the Sidebar. This will limit your options to Vista. Alternatively, you could look into shell integration (perhaps a knowledge of COM would help you here) or the ShowInTaskbar property of a form

AKNR Chandra Sekhar19-Mar-09 8:47

AKNR Chandra Sekhar

19-Mar-09 8:47

Hello,
You may be looking for docking your application with Desktop. You can look at the following article.. http://www.codeproject.com/KB/shell/csdoesshell3.aspx[^]

Rgds,
AKNR

Saving User and Application Settings in WinForms

Sokka9328-Feb-09 21:29

Sokka93

28-Feb-09 21:29

I want to save changes in my C# form. So I tried this. There are 3 buttons on my form but the code saves only button3's location. What should I do? Please help me!

foreach (Button a in Form1.ActiveForm.Controls)
 {
 Properties.Settings.Default.SavedSetting3 = a.Location;
 }
Properties.Settings.Default.Save();

Thanks in advance

Re: Saving User and Application Settings in WinForms

ABitSmart1-Mar-09 0:30

ABitSmart

1-Mar-09 0:30

You can save in one setting entry only one value. From what you are doing, you are trying to save 3 different locations to one setting entry(SavedSetting3) which is wrong. In each loop execution you are overwriting the last set value and hence, the value which is last written (button3 I guess) is the one which is saved. You will need to create 3 different setting's entry to save each of the buttons location.

Re: Saving User and Application Settings in WinForms

Sokka931-Mar-09 0:54

Sokka93

1-Mar-09 0:54

Thank you. What if I don't know how many buttons or controls exist? How can I create a setting for each control? I'm working on a programme that users can add controls at run time.

Re: Saving User and Application Settings in WinForms

Henry Minute1-Mar-09 1:23

Henry Minute

1-Mar-09 1:23

You can have these settings saved for you automatically. Just have a google for 'App.Config' or 'Saving Form Location' and read up about it.

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.”

File Not Found Exception Handling

Lim Yuxuan28-Feb-09 21:29

Lim Yuxuan

28-Feb-09 21:29

Hi I am trying to handle a file not found exception by creating the specified text file if it does not exists.

void RetrieveData()
{
if(File.Exists("books.txt") == false) // if file doesnt exists
{
File.Create("books.txt"); // create the file
}
//Create a stream reader object to read from "books.txt"
StreamReader DataReader = new StreamReader("books.txt");
}

I did a test run and remove the books.txt file from the current working directory on purpose and when i start debugging all I get is this exception :

The process cannot access the file 'C:\Documents and Settings\Administrator\My Documents\NYP Work\C#\MiniProject 2009\PhotoAlbum_V2\bin\Debug\books.txt' because it is being used by another process.

Any suggested solutions ?

Re: File Not Found Exception Handling

0x3c028-Feb-09 23:16

Re: File Not Found Exception Handling

28-Feb-09 23:16

Your problem lies with the File.Create method. It returns a FileStream instantiation. Until you close the FileStream, you cannot read the file without requesting different access to it. Try something like this

void RetrieveData()
{
    Stream bookStream = new FileStream("books.txt", FileMode.OpenOrCreate);

    using(StreamReader booksReader = new StreamReader(bookStream))
    {
        //Do what you want with booksReader here, the using block will automatically close the streams to avoid memory leaks
    }
}

The trick here is creating a new FileStream with FileMode.OpenOrCreate. If the file exists, it is opened; if it doesn't exist, it is created and then opened. If you want to check whether the file is empty (it's pointless reading from an empty file), check whether bookStream.Length is equal to zero. This will also tell you if the file is newly created because the newly created file will be empty

Lim Yuxuan1-Mar-09 1:27

Lim Yuxuan

1-Mar-09 1:27

thanks it worked well that way.

building network in form of a graph

sunnyk8628-Feb-09 20:52

sunnyk86

28-Feb-09 20:52

How do we build a network ..

Re: building network in form of a graph

Yusuf28-Feb-09 21:16

Re: building network in form of a graph

28-Feb-09 21:16

try this[^]

Yusuf

Eytukan1-Mar-09 2:41

Eytukan

1-Mar-09 2:41

Or here http://www.facebook.com/[^]

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

toolbar moving

shefa' isied28-Feb-09 20:42

shefa' isied

28-Feb-09 20:42

hi,
how i can move the toolbar in the running time using c#?

Re: toolbar moving

Yusuf28-Feb-09 21:17

28-Feb-09 21:17

try this[^]

Yusuf

Socket

mrithula828-Feb-09 20:39

28-Feb-09 20:39

Hi I have written code for client server communication using Tcp and Udp..It works well...I have created a function for the client and called the function from the form1.cs in VS.NET...Now this acts as the client and the server is a separate code..

Now i want both the client and server to communicate...
With a button click i want the message from the client to be sent to the server...So i used a ListBox control in the form...with a button click im able to send message to the server through the socket connection..

Server runs in the console...I am able to send message from the tool i.e client to the console...Once the server the receives the message i require the server to send a message back to the client as an acknowledgement (i.e. the message must be displayed to the listbox control in the form) How do i do this?Please help me out with this.thanks for any help in advance..

Yusuf28-Feb-09 21:22

28-Feb-09 21:22

If you got the client to communicate with the server, then the same method is used to talk back from the server to the client

to show your message in the listbox use

ListBox.Items.Add()

Here is ListBox documentation[^]

Yusuf

mrithula828-Feb-09 22:47

28-Feb-09 22:47

if i use listBox1.Items.Add()...
it gives me an error stating

listBox1 does not exist in the current context

0x3c028-Feb-09 23:23

28-Feb-09 23:23

You need to add a ListBox control to your form. listBox1 will then refer to that control, and add whatever you call the Add method with as arguments. Be careful though; it will add the items, but displays the ToString representation of them. If it's your own class, override the method to provide your own implementation of ToString

mrithula828-Feb-09 23:39

28-Feb-09 23:39

Hi,
I have a form1.cs which has a listBox control...
I have defined the server class in another file using(File->
New->File option)but in the same project...So im not able to
use listBox1.Items.Add()...
If i do so it gives me an error

0x3c028-Feb-09 23:54

28-Feb-09 23:54

Use the server class in the usual way. When you get told that you have received a message, add it to the listbox

mrithula81-Mar-09 17:22

1-Mar-09 17:22

Hi,
This is the server code:

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
public class UdpServer
{
    public static void Main()
    {
        try
        {
        int recv;
        byte[] data = new byte[1024];
        IPEndPoint ipep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
        Socket newsock = new Socket(AddressFamily.InterNetwork,SocketType.Dgram, ProtocolType.Udp);
        newsock.Bind(ipep);
        Console.WriteLine("Waiting for a client...");
        IPEndPoint sender = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
        EndPoint tmpRemote = (EndPoint)(sender);
        recv = newsock.ReceiveFrom(data, ref tmpRemote);
        Console.WriteLine("Message received from {0}:", tmpRemote.ToString());
        Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
        string wel = "Welcome to my test server";
        data = Encoding.ASCII.GetBytes(wel);        
        newsock.SendTo(data, data.Length, SocketFlags.None, tmpRemote);
         listBox1.Items.Add(data);
        ASCIIEncoding asen = new ASCIIEncoding();
        newsock.Send(asen.GetBytes("The string was recieved by the server."));
        Console.WriteLine("\nSent Acknowledgement");
            listBox1.Items.Add("The string was recieved by the server.");         
        newsock.Close();
       }
            catch(Exception e)
           {
                   Console.WriteLine("Error..... " + e.StackTrace);
            }}}

This is Form1.cs where i have called the client

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text; 
using System.Net;
using System.Net.Sockets;
using System.Windows.Forms;
namespace WindowsApplication13
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Callback();
        }
    
        private void Callback()
        {
            try
            {                
                byte[] data = new byte[1024];
                listBox1.Items.Add("Connecting....");
                IPEndPoint ipep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
 Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
                listBox1.Items.Add("Connected");
                data = Encoding.ASCII.GetBytes("welcome");
                listBox1.Items.Add("Transmitting...");
                server.SendTo(data, data.Length, SocketFlags.None, ipep);
             IPEndPoint sender = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
                EndPoint tmpRemote = (EndPoint)sender;
                // data = new byte[1024];
                int recv = server.ReceiveFrom(data, ref tmpRemote);
      //Console.WriteLine("Message received from {0}:", tmpRemote.ToString());
     listBox1.Items.Add(/*"Message received from {0}:",*/ tmpRemote.ToString());
                //Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
                listBox1.Items.Add(Encoding.ASCII.GetString(data, 0, recv));
           listBox1.Items.Add("Stopping client");
                server.Close();
            }
            catch (Exception e)
            {
                Console.WriteLine("Error..... " + e.StackTrace);
            }}}}

I have sent a string Welcome to the server and this works well
The following lines are displayed in the list box control
But the other listBox1.Items.Add()does not work..
What changes should i make to display

listBox1.Items.Add("Connecting....");
listBox1.Items.Add("Connected");
listBox1.Items.Add("Transmitting...");

mrithula81-Mar-09 18:48

How to Copy Form in Project ?

1-Mar-09 18:48

Hi,
I have made some changes to the above code and i have made the client and the server to communicate...
Now i need to perform a small check...
i have sent a string hello from the client to server...
the string is received in the server...Once it is received i want to check whether the received string is right...if it is right it must send another message to the client...So i used a" if" loop....When i use this loop im not able to receive the message from the server...
Please tell me the changes

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

public class UdpServer
{
    public static void Main()
    {
        try
        {
        int recv;
        byte[] data = new byte[1024];
        IPEndPoint ipep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);

        Socket newsock = new Socket(AddressFamily.InterNetwork,SocketType.Dgram, ProtocolType.Udp);

        newsock.Bind(ipep);
        Console.WriteLine("Waiting for a client...");

        IPEndPoint sender = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
        EndPoint tmpRemote = (EndPoint)(sender);

        recv = newsock.ReceiveFrom(data, ref tmpRemote);

        Console.WriteLine("Message received from {0}:", tmpRemote.ToString());
        Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));//hello is received
 
        if (Encoding.ASCII.GetString(data)=="hello")
        {
            data = new byte[1024];
            string ss = "Welcome to the Server";
            data = Encoding.ASCII.GetBytes(ss);
            newsock.SendTo(data, data.Length, SocketFlags.None, tmpRemote);
        }

        Console.WriteLine("\nSent Acknowledgement");
        newsock.Close();
    }  
       
            catch(Exception e)
           {
                   Console.WriteLine("Error..... " + e.StackTrace);
            }
    }
}

E_Gold28-Feb-09 20:12

E_Gold

28-Feb-09 20:12

Hi Evryone
How can I copy Form (Code + designing) in project and change his Name ?
(I work on WinCE)

thank's for any help

Re: How to Copy Form in Project ?

Yusuf28-Feb-09 21:26