Re: Manipulating Dataset coluns bound to datagrid - C# Discussion Boards

Re: Custom Forms

Kannan Kalyanaraman19-Jun-03 22:20

Kannan Kalyanaraman

19-Jun-03 22:20

I think Terrarium[^] will be a good start.

Cheers,
Kannan

where did my toolbox form controlls go???

ken-l119-Jun-03 6:10

ken-l1

19-Jun-03 6:10

Not sure what I did but the form controls in the Toolbox have dissapeared. The only remaining control is the pointer.
I am using Visual c#.net.... 2003 edition.

Does anyone know how to correct this ???

Thanks,
Ken

Re: where did my toolbox form controlls go???

leppie19-Jun-03 7:06

leppie

19-Jun-03 7:06

ken-l1 wrote:
Does anyone know how to correct this ???

Make sure you have a design surface active Smile | :)

<a TITLE="See my user info" href=http://www.codeproject.com/script/profile/whos_who.asp?id=38829>leppie<a>::<a TITLE="Go to all articles  written by me" href=http://www.codeproject.com/script/articles/list_articles.asp?userid=38829>AllocCPArticle</a>(<a TITLE="Go to my latest, greatest article!" href=http://www.codeproject.com/useritems/dfamachine.asp >Generic DFA State Machine for .NET</a>);

Re: where did my toolbox form controlls go???

dazinith19-Jun-03 7:30

dazinith

19-Jun-03 7:30

the toolbox has several sections in it including:
Data
Dialog Editor
Components
Windows Forms
General

if you are in the General section all you will see is 'Pointer'.. also make sure you have a dialog selected to edit like another user pointed out.

still a newb.. cut me some slack :P
-dz

Manipulating Dataset coluns bound to datagrid

Steve McLenithan19-Jun-03 5:53

Steve McLenithan

19-Jun-03 5:53

I have a chunk of data that is pulled from a database. I want to insert a new column into the dataset, and have every cell in that new column have new values based on an existing columns values. IE:

-Price----Amt.------NewColumn
---------------------------
   100  |   2     |
   220  |   4     |
   335  |   5     |
   400  |   6     |
   554  |   8     |
   655  |   9     |
        |         |

Say I want 'NewCol' to equal Price * 2.2, so the new data set would look like this:

-Price----Amt.------NewColumn
---------------------------
   100  |   2     | 220
   220  |   4     | 484
   335  |   5     | 737
   400  |   6     | 880
   554  |   8     | 1218.8
   655  |   9     | 1441
        |         |

I hope this isn't too confusing. It's really just like I would do using Excel. having a column's values based in part on another column.

How would I approach this?

Steve
McLenithan

Is Bert Evil? | Homer: "Hello, operator, gimme the number for 911!"

Re: Manipulating Dataset coluns bound to datagrid

Dimitris Iliopoulos19-Jun-03 8:13

Dimitris Iliopoulos

19-Jun-03 8:13

add an expression column. The way to do that is

Dataset.Tables["tablename"].Columns.Add("columnname",Type.GetType("the type like System.String"), "the expression like equal Price * 2.2")

so

Dataset.Tables["tablename"].Columns.Add("NewCol",Type.GetType("System.Double"), "equal Price * 2.2")

that's it

From Greece:
Dimitris Iliopoulos
dimilio@yahoo.com

Re: Manipulating Dataset coluns bound to datagrid

Steve McLenithan19-Jun-03 8:23

Steve McLenithan

19-Jun-03 8:23

Thanks for the reply. I am trying to do what you have shown but I am getting an error; Where you put System.String for the

'int' denotes a 'class' where a 'variable' was expected

I dont get that because intellisense is showing it should be something like you had shown.

Also how do I figure out the expression. Do I simply use the names of the database columns in a mathematical formula string?

Thanks for the help

Steve
McLenithan

Is Bert Evil? | Homer: "Hello, operator, gimme the number for 911!"

Re: Manipulating Dataset coluns bound to datagrid

Steve McLenithan19-Jun-03 8:36

Steve McLenithan

19-Jun-03 8:36

I got it. Thank you so much for the help. This is what I ended up doing:

ds.Tables["archive"].Columns.Add("spread",System.Type.GetType("System.Int32"),"av * 2.2");

Where 'av' is the name of another column in the table.

It works. Thanks again! Cool | :cool:

Steve
McLenithan

Is Bert Evil? | Homer: "Hello, operator, gimme the number for 911!"

How Timer works

puppiesLover19-Jun-03 5:41

puppiesLover

19-Jun-03 5:41

Completely new to C#.
can anyone give me a big picture on how Timer works in C#?
For example, what is the framework for me to do a certain job, say methodX(), every 5 seconds?
thanks in advance!

Re: How Timer works

Manster19-Jun-03 6:11

Manster

19-Jun-03 6:11

Timers are really simple to use in C#.

All you have to do is declare a timer:
private System.Windows.Forms.Timer timer1; or drag it onto your form.

Setup the interval and add a message handler:
this.timer1.Enabled = true;
this.timer1.Interval = 1000;
this.timer1.Tick += new System.EventHandler(this.timer1_Tick);

private void timer1_Tick(object sender, System.EventArgs e)
{
// add your code here. right now tis fucntion will get called once every second.
}

Hope this helps.

How ow to alternate color on items of combo/list box, gurus?

Khang Nguyen19-Jun-03 5:10

Khang Nguyen

19-Jun-03 5:10

Good morming gurus,

Do you know a good source on how to alternate color on every other items of list box or combo box?

Thanks so much
Khang Nguyen
Big Grin | :-D

Re: How ow to alternate color on items of combo/list box, gurus?

Manster19-Jun-03 6:28

Manster

19-Jun-03 6:28

This is what I did in a listview control. The code below changes every other row to a different back color.

private void ColorRow()
{
if( m_bListViewBackColor )
{
m_bListViewBackColor = false;
}
else
{
m_bListViewBackColor = true;
}

ListViewItem Lvi;

// Add a listitem
Lvi = m_ListView.Items.Add( 1 );
Lvi.SubItems.Add( "John" );
Lvi.SubItems.Add( "Smith" );

if( m_bListViewBackColor )
{
Lvi.BackColor = Color.Crimson;
}
else
{
m_bListViewBackColor = false;
Lvi.BackColor = Color.White;
}
}

Declare m_bListViewBackColor at the top of your app.

This isn't exactly what you're looking for, but I think it should get you headed in the right direction.

Re: How ow to alternate color on items of combo/list box, gurus?

Khang Nguyen19-Jun-03 11:11

Khang Nguyen

19-Jun-03 11:11

Thank you very much for the tip, Manster!
Khang Nguyen

Fast image processing

aeros19-Jun-03 4:50

aeros

19-Jun-03 4:50

Hi !

I'd like to implement basic image processing like gamma, brightness and contrast.
I found on codeproject an excellent article by Christian Graus on image processing with GDI+.
Problem is that method is very slow. I compare it with Microsoft Photo Editor (included with MS Word) and it's much faster.
Maybe my method isn't the best one:

On Filter Attribut Changed:
Bitmap b = m_OriginalImage.Clone();
Filters.Brightness(b, BrightnessAttribut);
Filters.Contrast(b, ContrastAttribut);
Filters.Gamma(b, GammaAttribut);
pictureBox.Image = b;
End

Help's appreciate.

Thanks

--
aer@s

Welcome dialog when app starts?

Andrey Kalganov19-Jun-03 3:50

Andrey Kalganov

19-Jun-03 3:50

Does anybody know how show "welcome" dialog while the the rest of the application is being loaded (C#)?

Thanks a lot,
Andrey

Re: Welcome dialog when app starts?

dazinith19-Jun-03 3:56

dazinith

19-Jun-03 3:56

here is what im using in my apps:

AboutBox myAboutBox = new AboutBox();
myAboutBox.Show();
myAboutBox.Refresh();
// **************** SPLASH SCREEN UP *********************

// do all of your loading here

Thread.Sleep(1500); // sleep for a second and a half so it at least shows for a second.

//
// Required for Windows Form Designer support
//
InitializeComponent();

myAboutBox.Hide();
myAboutBox.Dispose();
// **************** SPLASH SCREEN DOWN *******************

i find that you need to call the Refresh() before doing anything cpu intensive or it might not show cause its too busy processing other stuff..

still a newb.. cut me some slack :P
-dz

Re: Welcome dialog when app starts?

Jose Fco Bonnin19-Jun-03 4:29

Jose Fco Bonnin

19-Jun-03 4:29

If you do a Thread.Sleep the rest of the application will not be loaded. Why don't you try something like that

<br />
public class Form1 : System.Windows.Forms.Form<br />
{<br />
	....<br />
	Form2 frm= new Form2();<br />
	public Form1()<br />
	{<br />
		Thread thread = new Thread(new ThreadStart(StartForm2));<br />
		thread.Start();<br />
		// Do your stuff<br />
		frm.Close();<br />
	}<br />
<br />
	private void StartForm2()<br />
	{<br />
		if (frm != null)<br />
			frm.ShowDialog();<br />
<br />
	}<br />
....<br />
}<br />

Re: Welcome dialog when app starts?

dazinith19-Jun-03 4:49

dazinith

19-Jun-03 4:49

if you look back at my code you'll see that the Thread.Sleep(1500) is just to pause for a second.. i know nothing is going to happen during that time..

right above that is where i load all of my stuff.. i just pause so that the splash screen is showed for at least a second, it serves no other purpose and can be removed. this is all in my constructor for my main form..

what is the benefit of creating a thread just to show and close the dialog when you could just show and hide the dialog around the section of code that does your loading?

AboutBox myAboutBox = new AboutBox();
myAboutBox.Show();
myAboutBox.Refresh();
// **************** SPLASH SCREEN UP *********************

// do all of your loading here <--- this is where i do all my loading.. 

// sleep for a second and a half so it at least shows for a second.
Thread.Sleep(1500);  // <---this can be removed, its not necessary, i just do it

//// Required for Windows Form Designer support//
InitializeComponent();

myAboutBox.Hide();
myAboutBox.Dispose();
// **************** SPLASH SCREEN DOWN *******************

still a newb.. cut me some slack :P
-dz

Re: Welcome dialog when app starts?

Jose Fco Bonnin19-Jun-03 5:02

Jose Fco Bonnin

19-Jun-03 5:02

I'm sorry if I'm offended you I didn't want to criticize your code.

What I'm saying is if that guy wants to show a form during the load of the real application, in my opinion is better to show it in a different thread because it guarantees that the form will be shown and you will not get a blank screen because the application is busy doing other things. But of course you can also use tricks like Refresh() or Application.DoEvents() doesn't matter.

Re: Welcome dialog when app starts?

dazinith19-Jun-03 5:06

dazinith

19-Jun-03 5:06

ah.. i was wondering why i had to refresh the form to make it show.. i guess i can see how having another thread could help them both.. especially if you wanted your loading form to have some sort of animation or something.. btw, i wasnt offended, i honestly wanted to know the purpose Smile | :)

still a newb.. cut me some slack :P
-dz

Re: Welcome dialog when app starts?

Anonymous20-Jun-03 1:07

Anonymous

20-Jun-03 1:07

Thanks guys for your replies.

Jose, when I try to close the "start" form, the main form losts focus. Any ideas how to dial with that?

------------------------
Andrey

Re: Welcome dialog when app starts?

dazinith20-Jun-03 7:46

dazinith

20-Jun-03 7:46

my guess is that if you just called Focus() it would get focus back

Form1.Focus();

thats my guess Smile | :)

still a newb.. cut me some slack :P
-dz

How to tell if something is selected in my listbox?

dazinith19-Jun-03 3:42

dazinith

19-Jun-03 3:42

i have a listbox and a button.. when you click on the button i want to remove what is selected in the listbox, but i need to be able to tell if something is selected in the box or not..

if (this.lvSDeduc.SelectedItems == null)
{	MessageBox.Show("You must select something to remove before clicking the remove button.");
	return;		}

ListViewItem objItem = this.lvSDeduc.SelectedItems[0];

this doesnt work, so when it gets to the SelectedItems[0] i crash since there is nothing selected.. any suggestions?

thanks in advance!

still a newb.. cut me some slack :P
-dz

Re: How to tell if something is selected in my listbox?

Dimitris Iliopoulos19-Jun-03 3:48

Dimitris Iliopoulos

19-Jun-03 3:48

use this code

if (this.lvSDeduc.SelectedItems.count == 0)
{ MessageBox.Show("You must select something to remove before clicking the remove button.");
return;
}ListViewItem objItem = this.lvSDeduc.SelectedItems[0];

i think it will work

From Greece:
Dimitris Iliopoulos
dimilio@yahoo.com

Re: How to tell if something is selected in my listbox?

dazinith19-Jun-03 3:53

dazinith

19-Jun-03 3:53

doh, should have thought of that one Smile | :)

thanks a ton!

still a newb.. cut me some slack :P
-dz

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