C# errors - C# Discussion Boards

Nish Nishant23-Mar-02 21:43

23-Mar-02 21:43

I have a problem.
I have a Mouse-down handler for a list box.
The problem is that the list box's selected item wont change till my handler has exited.
Lets say the list box contains two items
----------
|apple |
|orange | <- selected
----------

Now if I click on apple and do a :-
MessageBox.Show(listbox.SelectedItem.ToString())

I still get orange. Next time I click I get apple.
What happens is that my handler gets called and only afterwards does the real handler gets called which changes the selected item index.

Now how do call the default handler

something like calling the base class handler

Regards
Nish Confused | :confused:

Oh, I don't know why she's
leaving, or where she's gonna go
I guess she's got her reasons but I just don't wanna know
'Cos for 24 years I've been living next door to Alice
24 years just waitin' for a chance
To tell her how I feel and maybe get a second glance
Now I gotta get used to not living next door to Alice

Re: How to call the default handler?

David Wengier23-Mar-02 23:47

David Wengier

23-Mar-02 23:47

Why are you using MouseDown? Why not just use click? The problem with MouseDown is that a "click" hasnt happened until the mouse has been released, ie, MouseUp.

To illustrate, if you hold your mouse down on a list box and move the mouse up and down, the selection will change. Thus lifting the mousebutton "locks in" the item that is selected.

Having said all of that, there may in fact be a way, i havent tried :p

--
David Wengier

TAC ad gone wrong: "Don't fool yourself, you're a bloody idiot."
Sonork ID: 100.14177 - Ch00k

Re: How to call the default handler?

Nish Nishant24-Mar-02 0:19

Nish Nishant

24-Mar-02 0:19

I need to use MouseDown as I am doing some drag/drop stuff

Nish

Re: How to call the default handler?

David Wengier24-Mar-02 1:06

David Wengier

24-Mar-02 1:06

You could always just use a simple hit-test to find out the item under the cursor. Assuming all of the items are the same height (ie, not OwnerDrawVariable) you could use :

private void listBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
	int iItem = (e.Y / listBox1.ItemHeight) + listBox1.TopIndex;
	if (iItem > listBox1.Items.Count - 1)
	{
		lblCount.Text = "none";
	}
	else
	{
		lblCount.Text = listBox1.Items[iItem].ToString();
	}
}

--
David Wengier

TAC ad gone wrong: "Don't fool yourself, you're a bloody idiot."
Sonork ID: 100.14177 - Ch00k

Re: How to call the default handler?

Nish Nishant24-Mar-02 1:11

Nish Nishant

24-Mar-02 1:11

Thanks David

But James Johnson suggested another solution to me :-

IndexFromPoint

Nish Smile | :)

Re: How to call the default handler?

David Wengier24-Mar-02 1:14

David Wengier

24-Mar-02 1:14

Nish [BusterBoy] wrote:
IndexFromPoint

ROFL... that exists? Thats about my luck these days Big Grin | :-D

--
David Wengier

TAC ad gone wrong: "Don't fool yourself, you're a bloody idiot."
Sonork ID: 100.14177 - Ch00k

Re: How to call the default handler?

Nish Nishant24-Mar-02 1:20

Nish Nishant

24-Mar-02 1:20

David Wengier wrote:
ROFL... that exists? Thats about my luck these days

Smile | :)

Nish

C# errors

Mazdak23-Mar-02 19:50

Mazdak

23-Mar-02 19:50

When I unhandled error thrown,it shown me error message,Is there any document to tell me how to fix this error?

Mazy

"So,so you think you can tell,
Heaven from Hell,
Blue skies from pain,...
How I wish,how I wish you were here."
Wish You Were Here-Pink Floyd-1975

Re: C# errors

James T. Johnson24-Mar-02 22:00

James T. Johnson

24-Mar-02 22:00

You can lookup what the exception is and what threw it to track down the offending code.

If you don't have the documentation locally it is available online @ MSDN.

James

Sonork ID: 100.11138 - Hasaki
"Smile your little smile, take some tea with me awhile.
And every day we'll turn another page.
Behind our glass we'll sit and look at our ever-open book,
One brown mouse sitting in a cage."
"One Brown Mouse" from Heavy Horses, Jethro Tull 1978

Control Arrays

23-Mar-02 13:02

How do you implement control arrays in C#?

Re: Control Arrays

23-Mar-02 13:28

And why is everyone so against them!!! I mean, every time I turn around, MS is throwing them out: Can't do them in VB.Net, couldn't do it (could hack it) in MFC, etc.

What is the deal!!!

Re: Control Arrays

David Wengier23-Mar-02 14:13

David Wengier

23-Mar-02 14:13

You dont need control arrays. In VB, they gave you the ability to write one event handler for a whole bunch of controls. With AddHandler in VB.NET (or using the += operator for events in C#) you can acheive the same thing, with the extra advantage that they dont even have to be the same type of controls, or the same events.

The other thing it let you do in VB was to add controls at run time. In VB.NET and C# this is now even easier.

Control arrays were an ugly way to do what .NET has made fairly elegant.

--
David Wengier

TAC ad gone wrong: "Don't fool yourself, you're a bloody idiot."
Sonork ID: 100.14177 - Ch00k

Re: Control Arrays

23-Mar-02 18:44

But I want to be able to use loops when I'm working with my controls...drawing them for instance...

An event isn't going to help me do that!

Re: Control Arrays

James T. Johnson23-Mar-02 18:42

James T. Johnson

23-Mar-02 18:42

Thats what collections are good for Smile | :)

foreach( MyControl c in MyControlCollection )<br />
{ <br />
  // use c<br />
}

James

Sonork ID: 100.11138 - Hasaki
"Smile your little smile, take some tea with me awhile.
And every day we'll turn another page.
Behind our glass we'll sit and look at our ever-open book,
One brown mouse sitting in a cage."
"One Brown Mouse" from Heavy Horses, Jethro Tull 1978

Interfacing to a COM object

Strait, Bryan23-Mar-02 12:25

Strait, Bryan

23-Mar-02 12:25

I am trying to inteface to the SENS COM object. I understand that I need to create a class that implements the GetConnectionPointContainer interface. I am unable to find the assembly or reference for which this resides in. I keep getting an error during compile time that I am missing a reference or assembly.

Any ideas? Thanks!

Bryan

Communication between 2 aspx pages

23-Mar-02 8:29

I have a framed webpage. On the left frame, I have search criteria in different ListBoxes, and I want to pass the selections from those ListBoxes to the right frame page, so that it can use those values to construct a select query, then show data there. How can I pass them in one aspx page (the one in left) and receive them in another( in right frame)?

Chris#

Re: Communication between 2 aspx pages

Christopher Lord25-Mar-02 12:32

Christopher Lord

25-Mar-02 12:32

The short answer: As a query string. I guess you could hack it up to post the data as well.

// Rock

1000

Nish Nishant23-Mar-02 5:35

Nish Nishant

23-Mar-02 5:35

Hurray!

The C# forum has 1000 posts now.

This is in fact the 1000th one. Talk about coincidence Wink | ;-)

Nish

Re: 1000

James T. Johnson23-Mar-02 9:00

James T. Johnson

23-Mar-02 9:00

DOH! It rolled over while I was sleeping Frown | :(

:-P

James

Sonork ID: 100.11138 - Hasaki
"Smile your little smile, take some tea with me awhile.
And every day we'll turn another page.
Behind our glass we'll sit and look at our ever-open book,
One brown mouse sitting in a cage."
"One Brown Mouse" from Heavy Horses, Jethro Tull 1978

Re: 1000

Nish Nishant23-Mar-02 9:07

Nish Nishant

23-Mar-02 9:07

James T. Johnson wrote:
It rolled over while I was sleeping

James

You can find cheer in the fact that a real nice guy like me took the opportunity to post the 1000th post.

Nish Wink | ;-)

Re: 1000

James T. Johnson24-Mar-02 9:42

James T. Johnson

24-Mar-02 9:42

True

C# vs. Unmanaged C++

gt4924f22-Mar-02 18:07

gt4924f

22-Mar-02 18:07

Does anyone have any resources or benchmarks on execution speed of C# and unmanaged C++ code? I'm primarily interested in intensive mathmatical algorithms. My gut feeling tells me that unmanaged code should be faster because it lacks the intermediate languages and compilers that are involved with C# (or the .NET framework in general). However, I did find this interesting benchmark that I find a little hard to believe. But who knows?

http://www.devhood.com/tutorials/tutorial_details.aspx?tutorial_id=203&printer=t

Re: C# vs. Unmanaged C++

Nish Nishant23-Mar-02 3:19

Nish Nishant

23-Mar-02 3:19

It's not a fair comparison to compare C# with unmanaged C++. Or do you actually mean managed C++?

Nish

Re: C# vs. Unmanaged C++

gt4924f23-Mar-02 5:04

gt4924f

23-Mar-02 5:04

I'm not sure I understand what you mean by not being "fair" to compare the two. I'm interested in knowing if C# truly does combine the benefits of C++ (speed, flexibility) with the benefits of a RAD language (ease of use). Or am I going to take a perfomance hit by switching to .NET and managed code. I mean, I know it's not "fair" to compare a Honda Civic EX to a Ferrari 360 Modena, but I sure know which one is faster. That's all I want to know.

Re: C# vs. Unmanaged C++

Nish Nishant23-Mar-02 5:33

Nish Nishant

23-Mar-02 5:33

Well then here goes :-

Unmanaged code will always run faster than managed code.
Thus unmanaged C++ will be faster than C# or any other .NET language including managed C++.

Among the managed languages, managed C++ produces slightly faster code cause the MC++ compiler has certain extra optimizations [I do not know the details, but I've heard Chris M rave about this several times]

Nish

Last Visit: 31-Dec-99 18:00 Last Update: 24-Jun-24 21:53

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