He definitely deserves the 5 :-) - C# Discussion Boards

Resize dynamically and set new string

15-Feb-08 0:32

Hello,

You could use StringCollection[^]

All the best,

Martin

Mircea Puiu15-Feb-08 0:47

15-Feb-08 0:47

string[] _securities = null;
_securities = new string[] 
	{
	    "XS0166639566 corp cusip","XS0184546371 corp cusip", "XS0307767474 corp cusip"
	};

And then, whenever you need to add a string:

Array.Resize<string>(ref _securities, _securities.Length + 1);
_securities[_securities.Length - 1] = "The new string";
</string>

SkyWalker

Guffa15-Feb-08 1:13

Guffa

15-Feb-08 1:13

No, please don't do that.

There is no way of resizing an array in .NET. What the Resize method does is to create a new array with the desired size and copy all the data from the old array.

If you do this in a loop, the performace degrades exponentially to the number of items.

Experience is the sum of all the mistakes you have done.

Mircea Puiu15-Feb-08 1:57

15-Feb-08 1:57

It was not about performance, why are you so upset?
He could use the StringCollection, but he simply wanted to use the string[] (I don't know why, ask him for that Smile | :)

). I just offered a solution to what he wanted.

Peace Wink | ;)

SkyWalker

Guffa15-Feb-08 3:34

Guffa

15-Feb-08 3:34

Mircea Puiu wrote:
It was not about performance, why are you so upset?

I'm not upset. I just wanted to point out that the solution is generally a bad method to use.

Eventhough the question didn't mention performance, some solutions scale so badly that they should never be suggested without explaining what happens when you use it with more than a minimal set of data.

Mircea Puiu wrote:
I just offered a solution to what he wanted.

No, you offered a solution to what he thought that he wanted. Smile | :)

Just because he asked for it doesn't mean that it's the method that he should use.

People often don't know what to ask for. It's quite common that they ask for the solution that they think that they should use rather than a solution to the actual problem that they have.

Experience is the sum of all the mistakes you have done.

Mircea Puiu15-Feb-08 4:02

15-Feb-08 4:02

You are right again ... Smile | :)

Have a nice weekend!

SkyWalker

He definitely deserves the 5 :-)

J4amieC15-Feb-08 2:06

J4amieC

15-Feb-08 2:06

voted 5 to even up the low-brain low-voters and because your advise was good.

Mircea Puiu15-Feb-08 2:18

System.Windows.Forms.Control Vs System.Windows.Controls

15-Feb-08 2:18

Yes, his point is well taken!

SkyWalker

Re: array

Guffa15-Feb-08 0:58

Guffa

15-Feb-08 0:58

Use a list instead of an array:

private List<string> _securities = new List<string>();

foreach (DataRow row in dsSecuritiesDetails.Tables[0].Rows) {
   _securities.Add(row["field2"].ToString() + " corp cusip");
}

Experience is the sum of all the mistakes you have done.

Re: array

Luc Pattyn15-Feb-08 5:45

Luc Pattyn

15-Feb-08 5:45

Hi,

use a collection (StringCollection, ArrayList, or generic List< string>) as others
indicated.

Then convert it to an array if you really need an array. ArrayList and generic List
have a ToArray() method for that purpose.

Smile | :)

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This month's tips:
- before you ask a question here, search CodeProject, then Google;
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VLC

Aparna.B15-Feb-08 0:20

Aparna.B

15-Feb-08 0:20

hi,

i have selected a camera for a live view through vlc i want to draw a rectangle in the certain areas of vlc.Is there any solutions for this problem.

Thanks in advance
Aparna

Re: VLC

Pete O'Hanlon15-Feb-08 1:18

Pete O'Hanlon

15-Feb-08 1:18

Aparna.B wrote:
i have selected a camera for a live view through vlc i want to draw a rectangle in the certain areas of vlc.Is there any solutions for this problem

Probably.

Deja View - the feeling that you've seen this post before.

My blog | My articles

kaminem15-Feb-08 0:14

kaminem

15-Feb-08 0:14

Hi all,

is there a way to cast a System.Windows.Controls.UserControl (.Net 3) to a System.Windows.Forms.Control (.Net2) ?

I have a Plugins system and I'm trying to plug some .Net3 components

Assembly l_assembly = Assembly.LoadFrom(AssemblyName);
Type l_type = l_assembly.GetType(TypeName, true);
Control l_itemControl = Activator.CreateInstance(l_type) as Control;

here I catch an Exception when I load a "Custom Control Library (WPF)"

Thanks

Re: System.Windows.Forms.Control Vs System.Windows.Controls [modified]

Dave Kreskowiak15-Feb-08 4:44

Dave Kreskowiak

15-Feb-08 4:44

lkort wrote:
is there a way to cast a System.Windows.Controls.UserControl (.Net 3) to a System.Windows.Forms.Control (.Net2) ?

No, there isn't. You cannot use a .NET 3.0 component in a .NET 2.0 app. You cannot load two different versions of the .NET CLR runtime into the same process.

Also, .NET 2.0 does not support WPF, so you can't do this at all.

You can do the opposite though. You can load a component that was developed under .NET 2.0 in a .NET 3.0 runtime app.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

modified on Friday, February 15, 2008 10:52 AM

How to perform Undo for Form Controls in C#?

nilam247715-Feb-08 0:01

nilam2477

15-Feb-08 0:01

I have a form with multiple TextBox controls and few other controls like comboBox, checkBox etc. I'm trying to implement Undo functionality for all the controls in the form. I'm using Push & Pop operations of Stack to store the control values.

My question is regarding the TextBox control. I would like to know on which event of TextBox control i can save the Text in the stack. If i use TextChanged event, then this event is triggered on each character typed.
I also know that TextBox Base provides Undo functionality but i dont want to use that, since my form contains multiple TextBox and other controls as well. And i would like to perform the Undo operation in sequence. Please help!

Re: How to perform Undo for Form Controls in C#?

Giorgi Dalakishvili15-Feb-08 0:34

Giorgi Dalakishvili

15-Feb-08 0:34

You could use Validating or MouseLeave event to check if the text has changed and store new value in stack

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Forms Issue

Harvey Saayman14-Feb-08 23:43

Re: Forms Issue [modified]

14-Feb-08 23:43

Hi guys

[The senario]
i have a form (FrmUsers) that selects some columns from my userTable and then databinds it to a DataGridView on creation

when the user double clicks a row in the datagrid view an instance of (FrmAddUser) displays with the selected users details filled in

then when you close (FrmAddUser) after editing, the user the data is updated to my db

[the question]
how do i tell (FrmUsers)with the DataGridView that instantiated the AddUser Window that it has to redo the data binding as to reflect the changes?

thanx

Harvey Saayman - South Africa
Junior Developer
.Net, C#, SQL
think BIG and kick ASS

you.suck = (you.passion != Programming)

Martin#14-Feb-08 23:57

14-Feb-08 23:57

Hello,

Tasks like this are mostely done with modal Windows called with ShowDialog().
The DialogResult of FrmAddUser tells FrmUsers if he has to Update his values.
The initialized Properties could be passed over the constructor from FrmAddUsers.
The return values could be passed over properties from FrmAddUsers.

pseudocode:

using(FormAddUser addUser = new FormAddUser(object initValues))
{
    if(addUser.ShowDialog() == DialogResult.OK)
    {
         object actUserInfos = addUser.ActUserInfos;
         ...
    }
}

You should also think of, if it makes sence to instanciate your FormAddUser always new.

All the best,

Martin

modified on Friday, February 15, 2008 6:29 AM

Re: Forms Issue

Harvey Saayman15-Feb-08 0:16

15-Feb-08 0:16

thanx martin!

never thaught of that... YOU ROCK as usual

Big Grin | :-D

TTYL

Harvey Saayman - South Africa
Junior Developer
.Net, C#, SQL
think BIG and kick ASS

you.suck = (you.passion != Programming)

Re: Forms Issue

Martin#15-Feb-08 0:35

15-Feb-08 0:35

Glad I could help!

All the best,

Martin

Dialog Issue

Harvey Saayman15-Feb-08 0:38

15-Feb-08 0:38

dude.. its not working

once the users details is updated i do (this.DialogResult = DialogResult.OK;) in(FrmAdduser)

and then in (FrmUsers) i hav this

<br />
FrmAddUser frmAddUser = new FrmAddUser(sqlConn);<br />
frmAddUser.MdiParent = this.MdiParent;<br />
frmAddUser.ShowDialog();<br />
<br />
if (frmAddUser.DialogResult == DialogResult.OK)<br />
{<br />
      dataBindDataGridView();;<br />
}<br />

but the if never returns true... any sugestions?

Harvey Saayman - South Africa
Junior Developer
.Net, C#, SQL
think BIG and kick ASS

you.suck = (you.passion != Programming)

Martin#15-Feb-08 0:46

15-Feb-08 0:46

Hello,

You have to set the property somehow yourselfe.

Normaly you have a Accept and an Cancel Button on your Form.
the Buttons have a Property called "DialogResult", which you have to set accordingly.

The Form has two properties called "AcceptButton" and "CancelButton", which you also have to set.

Look at the Doku [^] for more infos about that!

All the best,

Martin

Harvey Saayman15-Feb-08 0:52

15-Feb-08 0:52

but im i not setting the property when i do this.DialogResult = DialogResult.OK; in frmAddUser?

Harvey Saayman - South Africa
Junior Developer
.Net, C#, SQL
think BIG and kick ASS

you.suck = (you.passion != Programming)

Martin#15-Feb-08 0:55

15-Feb-08 0:55

HarveySaayman wrote:
but im i not setting the property when i do this.DialogResult = DialogResult.OK; in frmAddUser?

???
If you set the DialogResult property of frmAddUser like this, it should have this value when you close the Form.

All the best,

Martin

Harvey Saayman15-Feb-08 1:04