Re: Multi-select ComboBox - C# Discussion Boards

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Re: Memory leak

Luc Pattyn8-Apr-07 13:05

Luc Pattyn

8-Apr-07 13:05

You're welcome.

Luc Pattyn

[My Articles]

Get Controls by name

swjam4-Apr-07 5:03

swjam

4-Apr-07 5:03

Is there a way to access each of the controls in a form by name programmatically?
i.e. without having to loop through each one
Tia.

I am a SysAdmin, I battle my own daemons.

Re: Get Controls by name

B.King4-Apr-07 5:50

B.King

4-Apr-07 5:50

Yes,
use the Controls Property of a Contailer like Form or Panel:

<br />
Control c = Controls.Find("name", true);   // if this is a Form<br />
Control c = panelXYZ.Controls.Find("name", true);   // if panelXYZ is a Panel ...<br />

How to specify an event handler

peterchen4-Apr-07 5:02

peterchen

4-Apr-07 5:02

If I have a class with an event, and a class that wants to attach to the handler:

class A
{
  public event EventHandler<SomeEventArgs> SomeEvent;
}

class B
{
  public void AttachToHandler(A a)
  {
    a.SomeEvent += ***;  // << here's my question
  }
   
  void SomeEventHandler(object sender, SomeEventArgs e) {... }
 
}

The VC# Express IDE ("press TAB to insert..") suggests:

a.SomeEvent += new EventHandler<SomeEventArgs>(SomeEventHandler);

However, the following also seems to work:

a.SomeEvent += SomeEventHandler;

Now the questions:
Is there a difference between the two? A "preferred style"?

We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
My first real C# project | Linkify!|FoldWithUs! | sighist

Re: How to specify an event handler

mikanu4-Apr-07 6:48

mikanu

4-Apr-07 6:48

I've always used the first method (using the New operator to instantiate a new delegate that will handle the event).
You can alway declare a variable that holds the reference to the event handler in advance and then use that as your handler like so:

<br />
<pre>   
   EventHandler eh;
   eh = New EventHandler(SomeEventHandler);
   a.SomeEvent += eh;
</pre><br />
<br />
this way you could later detach the event handler too, like so:<br />
<br />
<code lang="C#"><br />
<pre>
   a.SomeEvent -= eh; //(as long as eh still references your event handler!)
</pre><br />
<br />
The second way seems to be a shortcut for the first (in which the compiler automatically generates the code that instantiated the delegate and than passes it your function).<br />
<br />
Hope this helps, but your best bet is to do some reading on delegates and event handlers in C#. <br />
<br />
 <br />
<br />
<div class="ForumSig">----<br />
<a href="www.digitalGetto.com">www.digitalGetto.com</a></div>

Multi-select ComboBox

Amatista4-Apr-07 4:46

Amatista

4-Apr-07 4:46

Hi,

I would like to have a ComboBox with multi-select, which is similar to ListBox (but ListBox has no DropDown). Could someone here give me some help? Thanks in advance.

BTW, I use Microsoft Visual Studio .Net 2005.

Regards,
Amatista

Re: Multi-select ComboBox

Douglas Troy4-Apr-07 6:00

Douglas Troy

4-Apr-07 6:00

Why would you want to do this? A ComboBox can only show a single selection at a time, when the list is not dropped, so therefore, a MultiSelect ComboBox makes no sense; which is why it's not an option ...

:..::. Douglas H. Troy ::..

Bad Astronomy |VCF|wxWidgets|WTL

Re: Multi-select ComboBox

Amatista4-Apr-07 22:27

Amatista

4-Apr-07 22:27

Thanks for your reply.

I am in charge of designing a full-text searching tool, a windows application, and the ComboBox is used for user to select file types for searching. I think it would be better if the user can select more than one file types. For the selected file types, if more than one item, they should be displayed, either comma or semicolon separated. Or is there another tool instead of ComboBox that I can use?

Does anyone have any suggestions to solve this issue?

Re: Multi-select ComboBox

Douglas Troy5-Apr-07 5:34

Douglas Troy

5-Apr-07 5:34

You should either be using a group of check box controls or a CheckedListBox. What you're wanting to do, goes against the standard design for that control.

:..::. Douglas H. Troy ::..

Bad Astronomy |VCF|wxWidgets|WTL

Re: Multi-select ComboBox

Amatista10-Apr-07 2:27

Amatista

10-Apr-07 2:27

Thanks for the information.

Control Draw delay on resize (Getting rid of it)

Muntyness4-Apr-07 3:11

Muntyness

4-Apr-07 3:11

I have a program which has a bunch of user controls. (Talking in the hundreds here) You can basically consider these controls as a bunch of buttons, with 2 images taken from the hard drive as Up and Pressed states. (The images are stored in memory when the control is first created, so there isn't any delay getting them from the hard drive.)

My problem is that when the program is minimized and then maximized, all the user controls redraw themselves. Is there any way to stop this?

Now, bearing in mind that RAM is not an issue, (well as long as it doesn't use more than 300MB or so of it anyway :P ) so if the only way to fix this is to use lots of memory, I don't mind.

Any suggestions?

PS. I'm assuming that the Windows GUI is discarding the conrol graphics as soon as they're off screen to improve performance. If this is true, then a way to stop this would be appreciated. (Also making it all get painted at the same time on startup would be appreciated. A slight delay while loading up the program would not matter)

Note: Using UserPaint, AllPaintingInWmPaint and DoubleBuffer doesnt help.

- Munty

Re: Control Draw delay on resize (Getting rid of it)

Stanciu Vlad4-Apr-07 7:52

Stanciu Vlad

4-Apr-07 7:52

When you minimize the window and maximize it back the controls have to redraw themselves because there was no part of them visible before for windows to perform local invalidation and restore data from internal cache...

If you want the maximum speed try caching the images into variables and render them to the form with unmanaged code (the BitBlt function[^] if I am not wrong).

Hope it helps ....

protected internal static readonly ... and I wish the list could continue ...

MSI uninstall problems

Vadim G.4-Apr-07 2:53

Vadim G.

4-Apr-07 2:53

Hi,
I have a Windows service, which should be installed using MSI.
The installation goes well.
When i run the MSI again to uninstall the service i have no errors occurred, but the service is still there and also the installation files.

Does anyone has any idea?
Thanks!

Vadim G.

Re: MSI uninstall problems

Douglas Troy4-Apr-07 3:51

Douglas Troy

4-Apr-07 3:51

Did ya stop the service first? and if so, did the service actually STOP?

If you attempt to uninstall a running service, that won't work.

"That's an idea."

:..::. Douglas H. Troy ::..

Bad Astronomy |VCF|wxWidgets|WTL

Re: MSI uninstall problems

Vadim G.4-Apr-07 4:44

Vadim G.

4-Apr-07 4:44

Thank you for reply.
But unfortunately i've already tried it -> unsuccessfully.
(It does succeed when i run InstallUtil)

bind list with datagrid & textbox

merwa4-Apr-07 2:43

merwa

4-Apr-07 2:43

How can I bind list with datagrid and textbox?

merwa

Re: bind list with datagrid & textbox

Not Active4-Apr-07 3:24

Not Active

4-Apr-07 3:24

Perhaps you could explain better, maybe tell us the problems you are having.

only two letters away from being an asset

Problem Displaying moneyfield in gridview

Bubbles24-Apr-07 1:56

Bubbles2

4-Apr-07 1:56

I am trying to display a moneyfield in a gridview but it displays as 14.9500 instead of 14.95$
Can anyone help please , I have tried editing as {0:c} and {0 Blush | :O

.00} which works for a datalist but not for the display in gridview. Confused | :confused:

Re: Problem Displaying moneyfield in gridview

kubben4-Apr-07 2:31

kubben

4-Apr-07 2:31

Create a template column and then in the label set the text to:
Text='<%# Convert.ToDouble(DataBinder.Eval(Container.DataItem,"moneyfield")).ToString("C") %>'

Hope that helps.
Ben

Re: Problem Displaying moneyfield in gridview

Hayder Marzouk4-Apr-07 2:33

Hayder Marzouk

4-Apr-07 2:33

Hi,
Set the DefaultCellStyle.Format property of the column to c

HTH.
Hayder Marzouk

Re: Problem Displaying moneyfield in gridview

Bubbles24-Apr-07 3:11

Bubbles2

4-Apr-07 3:11

Thanks for your prompt reply but
when I edit Gridview columns I can't find this property. Confused | :confused:

Re: Problem Displaying moneyfield in gridview

Hayder Marzouk4-Apr-07 4:05

Hayder Marzouk

4-Apr-07 4:05

Hi,
My response works in a .Net 2.0 Windows Forms application not is an ASP.NET Project.
So...
- Edit the gridview columns
- Select ure column
- Select the property DefaultCellStyle and click the button in the right.
- You will find the Format property in a new opened property form
- Set the property to c

HTH.
Hayder Marzouk

Re: Problem Displaying moneyfield in gridview

Bubbles24-Apr-07 5:01

Bubbles2

4-Apr-07 5:01

Thanks a lot for your help
I am using an ASP.NET web site.

Appliction like taskbar

Muhammad Nauman Yousuf4-Apr-07 1:54

Muhammad Nauman Yousuf

4-Apr-07 1:54

Hi,

I have developed an application (i.e. a rss news reader) it reads news from any rss source.

Now the problem is that i have selected its position just over the taskbar and always on TOP ; issue is that my news reader overlaps all the applictions.

I want my RSS News Reader to appear as task bar appears (i.e. all application launched should be above as in the case of windows task bar)

Thank you!

"Mess with the Best, Die like the rest"

Re: Appliction like taskbar

originSH4-Apr-07 2:10

originSH

4-Apr-07 2:10

Always on top means your application will always be on top :P the only applications that can appear over it are others that have set always on top Wink | ;)

Last Visit: 31-Dec-99 18:00 Last Update: 7-Jun-24 4:49

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