C# Discussion Boards - CodeProject

18-Jul-07 22:40

Hello All,

I am trying to bind the listbox to a column of the datatable. If i try directly on the click of the button then it will display the data. but, if i am trying to do this by creating a thread for this process it is doing nothing, no error is shown. Please help me.

Thanks in advance.

Bharath.S Ron

Eduard Keilholz18-Jul-07 22:47

18-Jul-07 22:47

I think an exception IS thrown however you catch it on some place. You cannot change GUI related things on a diffrent thread.

Try creating a delegate and call the delegate from your diffrent thread using Invoke()

for example :

<br />
private delegate void doBindListbox();<br />
private void BindListbox()<br />
{<br />
// Code to bind listbox<br />
}<br />

and call the delegate from your diffrent thread like so :

<br />
this.Invoke(new doBindListbox(BindListbox));<br />

.: I love it when a plan comes together :.
http://www.zonderpunt.nl

Ron.S18-Jul-07 22:58

18-Jul-07 22:58

Hi,

Is this the correct way?
trd = new Thread(new ThreadStart(this.Invoke(new delegateloaddata(loaddata))));

delegateloaddata = delegate.
loaddata = is the method which has to be called through thread

Bharath.S Ron

Eduard Keilholz19-Jul-07 0:57

19-Jul-07 0:57

No, it's not...

<br />
private void StartMyThread()<br />
{<br />
ThreadStart ts = new ThreadStart(InvokeBinding);<br />
Thread th = new Thread(ts);<br />
th.Start();<br />
}<br />
<br />
private void InvokeBinding()<br />
{<br />
this.Invoke(new doBindListbox(BindListbox));<br />
}<br />

See the example in my previous post....

.: I love it when a plan comes together :.
http://www.zonderpunt.nl

Ron.S19-Jul-07 2:41

19-Jul-07 2:41

Thank you.

I tried that method it is working and loading the data into the listbox but, it is not working as a thread. I cannot stop it in between.

Bharath.S Ron

Eduard Keilholz19-Jul-07 3:16

19-Jul-07 3:16

What do you mean with :

Bharath.S.Ron wrote:
I cannot stop it in between.

.: I love it when a plan comes together :.
http://www.zonderpunt.nl

Ron.S19-Jul-07 19:39

19-Jul-07 19:39

Hi,

AS i am trying to impliment that as a thread , i want to stop it in between as well.
stop in the sense, the form should not freeze while performing that function, i should be able to click other buttons as well while this is being doing its job.

Bharath.S Ron

Ron.S19-Jul-07 20:30

Visual studio error on load

19-Jul-07 20:30

this is the code which i am using.

public void loaddata()
{
try
{
conn = new SqlConnection("Data Source=local; Initial Catalog=Northwind; User ID=sa; Password=; Persist Security Info =True;");
adpt = new SqlDataAdapter("Select * from Categories", conn);
ds = new DataSet();
adpt.Fill(ds);
listBox1.DataSource = ds.Tables[0];
//trd
listBox1.DisplayMember = "CategoryName";
Thread.Sleep(1000);
//trd.Start();
}
catch (SqlException ex)
{
MessageBox.Show(ex.Message.ToString());
}
}

on click of the button i am calling that thread.

private void btnStart_Click(object sender, EventArgs e)
{
try
{
// this is wokring

ThreadStart myThreadDelegate = new ThreadStart(loaddata);
trd = new Thread(myThreadDelegate);
trd.Start();
trd.IsBackground = true;
// till here
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString());
}

}

this below code is to stop the thread.
private void btnStop_Click(object sender, EventArgs e)
{
//Thread trd = new Thread(new ThreadStart(this.loaddata));
//trd.Abort();
try
{
if ((trd.ThreadState == ThreadState.Running )|| (trd.ThreadState==ThreadState.Background))
{
trd.Abort();
}

}
catch (ThreadStateException Ex)
{
MessageBox.Show(Ex.ToString(), "Exception",
MessageBoxButtons.OK, MessageBoxIcon.Error,
MessageBoxDefaultButton.Button1);
}
}

please help me..

Bharath.S Ron

Custom Tab Control

T.EDY18-Jul-07 22:39

T.EDY

18-Jul-07 22:39

Hi,

I Have Some Problem how can we bind data into tab control..for example:

i have a table name Working, in first column i have field name "Id" for primary key and i make it autoincrement, and in the second column i have field name Status..what makes me confuse if on field status have 2 value :"typing, printing"..how can i make tab control have 2 tabPages name "typing" and "printing"

Please Help me coz i'm new in C#...

Thanks and Regard,

TCim

Russell Jones18-Jul-07 22:29

Russell Jones

18-Jul-07 22:29

I'm getting the following error:

Project FooBar could not be opened because the Microsoft Visual C# .NET compiler could not be created.

I reinstalled VS as recommended by the next line of the error message and it all worked fine.

This morning i open VS and guess what, I get the message again. Reinstalling took me hours yesterday and reduced my PC to a uselesss whirring mess for most of that time. It did however fix the problem for the last few hours of the day.

The suggestions i see on the web are that this problem is due to having a pathname over 260 characters in the project but i've moved my project folder to c and it stil doesn't open.

Has anyone else suffered this problem and found a fix?

Thanks

Russell

Re: Visual studio error on load

originSH18-Jul-07 22:50

originSH

18-Jul-07 22:50

I assume you've googled and worked through the results?

http://www.google.co.uk/search?hl=en&q=could+not+be+opened+because+the+Microsoft+Visual+C%23+.NET+compiler+could+not+be+created.&meta=[^]

Re: Visual studio error on load

Russell Jones18-Jul-07 22:57

Russell Jones

18-Jul-07 22:57

yeah,

strangely One of the guys found a solution suggested by ReSharper. I installed Resharper thinking it might tell me what was wrong. When I opened the project my cursor changed to a biohazard symbol with a green arrow and magically my project now works.

Who knows what was up with it, I hope I'm not back here tomorrow having suffered the same problem when i turn my PC on in the morning.

Russell

Re: Visual studio error on load

originSH18-Jul-07 23:56

originSH

18-Jul-07 23:56

wow! it might be worth going over to the resharper forums and asking if they've done a fix for the issue Smile | :)

handle Printer

Chatura Dilan18-Jul-07 22:17

Chatura Dilan

18-Jul-07 22:17

I'm working on a project on controlling the printer using C#. Such as restrict printing, counting no of pages.

I need references...
and I like to share ideas, if you have worked on that kind of project.

Any ideas? any links you know?

Thanks. Smile | :)

Chatura Dilan

Changing color while drag mouse

satsumatable18-Jul-07 22:11

satsumatable

18-Jul-07 22:11

Hi,

I want to change the color of Panel when i drag the mouse, that is color should be changed only where am dragging rest of the area should be as it is.

I have mouse position as like below

temp.X = e.X ;
temp.Y = e.Y ;
mMousePos = this.panel1.PointToScreen (temp);

I want to set the color for the area btw e.X and e.Y

Re: Changing color while drag mouse

Martin#18-Jul-07 22:51

Martin#

18-Jul-07 22:51

Hello,

I think it's best to create an image for your panel and get a Graphics object from that.
With this Graphics object you than can do a lot of fancy stuff.

Here is an example with an panel and MouseMove event:

private Graphics panelGraphics = null;
private Pen panelPen = null;
private Point oldPosition;
private bool init=false;
private void panel2_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
    if(panel2.BackgroundImage==null)
    {
        panel2.BackgroundImage= new Bitmap(panel2.Width, panel2.Height);
    }
    if(panelGraphics==null)
        panelGraphics = Graphics.FromImage(panel2.BackgroundImage);

    if(panelPen==null)
        panelPen= new Pen(Color.Red,2);

    if(init)
    {
        Point newPostion = new Point(e.X,e.Y);
        panelGraphics.DrawLine(panelPen, oldPosition, newPostion);

        Refresh();
    }
    else
        init=true;

    oldPosition = new Point(e.X,e.Y);
}

Hope it helps!

Note: I instanciated the Graphics and Pen objevt only once, but you have to dispose them in your forms Dispose method.

panelGraphics.Dispose();
panelPen.Dispose();

All the best,

Martin

Character not recognised when reading file

Sean_B18-Jul-07 22:10

Sean_B

18-Jul-07 22:10

Hi,

I'm reading a file using the stream reader into a string, and the character £ which is in the file appears as a sqare box in the string, which I assume means it is unrecognised.
I'd be grateful if someoone can tell me how to get round this.

Sean

Re: Character not recognised when reading file

Guffa18-Jul-07 23:52

Guffa

18-Jul-07 23:52

If the file is not encoded using UTF-8, you have to specify the encoding when creating the stream reader.

---
single minded; short sighted; long gone;

Xml Serialization

jpeg18-Jul-07 21:58

jpeg

18-Jul-07 21:58

Hello, I have one problem in serializing a class using .NET Serialization

for example, I have got something like this :

<br />
class Parking<br />
{<br />
  public List<Vehicle> vehicles<br />
  public Parking() { /*...*/ }<br />
<br />
  /* */<br />
}<br />
<br />
class Vehicle <br />
{<br />
  /* .... */<br />
}<br />
  <br />
class Truck:Vehicle<br />
{<br />
  /* .... */<br />
}<br />
<br />
class Car:Vehicle<br />
{<br />
  /* .... */<br />
}<br />
<br />
class Motorbike:Vehicle<br />
{<br />
  /* .... */<br />
}<br />

I have been trying to serialize a 'Parking' object and the better I got was :

<br />
<parking><br />
    <Vehicles><br />
    <Car> .... </Car><br />
    <Car> .... </Car><br />
    <Truck> .... </Truck><br />
    <Car> .... </Car<br />
    <Truck> .... </Truck><br />
    <Motorbike> .... </Motorbike><br />
    .....<br />
  </Vehicles><br />
</parking>

But my aim is to get this type of XML string (no 'Vehicles' node):

<br />
<parking><br />
  <Car> .... </Car><br />
  <Car> .... </Car><br />
  <Truck> .... </Truck><br />
  <Car> .... </Car<br />
  <Truck> .... </Truck><br />
  <Motorbike> .... </Motorbike><br />
  .....<br />
</parking><br />

Have you got any idea to obtain this result ?
Thank you for your help !

jpeg

Eduard Keilholz18-Jul-07 22:50

18-Jul-07 22:50

You can ignore object from being xml serialized using the XmlIgnore attribute

<br />
[XmlIgnore()]<br />
public List vehicles<br />

.: I love it when a plan comes together :.
http://www.zonderpunt.nl

jpeg18-Jul-07 23:43

jpeg

18-Jul-07 23:43

Thank you Eduard for your answer but my problem is not to exclude the list.

The class Parking only contain a List<Vehicle> called 'Vehicles'.

the problem is that I get :

<parking><br />
  <vehicles><br />
     .... all vehicules (classes Car, Truck, Motorbike ...)<br />
  </vehicles><br />
</parking><br />

I only want the 'vehicles' tags to disappear and 'Car', 'Motorbike' or 'Truck' vehicles to inside the 'parking' tags.

With your solution, I get :
</parking> (the content of the 'Vehicles' list is not serialized)

jpeg

Martin#18-Jul-07 23:49

Martin#

18-Jul-07 23:49

Hello,

I don't think that you could deserialze it correctly once it was modified this way.
And I also don't think there is a way to serialize it the way you want it.

All the best,

Martin

Eduard Keilholz19-Jul-07 0:01