Re: TabStops in ListBox - C# Discussion Boards

27-Jun-03 2:59

How can I set the Tab-Stops in a ListBox to have all Items that are seperated with '\t' aligned. In C++/MFC (CListBox) it was with SetTabStops() but now in C#/.NET ???
I fount the Property 'UseTabStops' to enable/disable the using of the TabStops, but Nothing to set the distance between the TabStops.

Greets
Roland

Rocky Moore27-Jun-03 23:15

Rocky Moore

27-Jun-03 23:15

You might find this handy:

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q318601[^]

Rocky Moore <><

Roland Bär29-Jun-03 21:13

29-Jun-03 21:13

Thank you for your Help, it works ... but unfortunately it works only for the ListBox but not for the CheckedListBox Frown | :(

I thougth, because the CheckedListBox derives from the ListBox, it should be for both the same, but it looks like i was wrong.

For me this looks like Microsoft has done their job only the half way ... Frown | :(

Roland

Rocky Moore30-Jun-03 0:45

Rocky Moore

30-Jun-03 0:45

Roland Bär wrote:
For me this looks like Microsoft has done their job only the half way ...

It is .NET 1.0 or 1.1, not .NET 6.0! Smile | :)

Much better start on .NET than their first web browser Wink | ;)

Rocky Moore <><

Roland Bär30-Jun-03 1:05

30-Jun-03 1:05

You're right, let's wait for .NET 3.0 (don't trust even numbers Wink | ;)

).

I was only disapointed because it was the second time in my first .NET Project that I had to use a [DllImport...] Workaround to get functionality that was done in MFC (or even in VB I think) easy.

Roland

Rocky Moore2-Jul-03 5:01

Rocky Moore

2-Jul-03 5:01

You know you can always build a class based on it and then override the painting to display the string as you wish. In .NET it is easy to extend classes! I have a entire set of controls (or most at least the ones I use all the time) wrapping the standard controls and then add in my own form style sheets to control the appearance and functionilty globally in the applications.

For an example, I can change color for read-only state, normal state, hover state. I am completely rebuilding a DatePicker control because I have not found one I like and have already rebuilt a checkbox that includes the text and checkbox within a box that has its background able to be set in any one of those three states.

In my current product, I wanted to keep all controls while browsing data in a read-only state and then when they hit a button to enable editing of the record, it will change the state and the appearanc of all the controls change without have those gray almost unreadable appearance of disabled controls.

All of this started when I got ticked because I could find no way to show the state of a tri-state checkbox when it was disabled.

Oh well, there I go rattling again. In short, it is easy to customize the output of controls so that you get the functionality you want.

Rocky Moore <><

declaring variables...

theJazzyBrain27-Jun-03 0:38

27-Jun-03 0:38

Is there a way to declare a variable without specifying the type and specifying the type later?

I need to declare a connection object to the DB but Idont know if it is SqlClient or OleDbClient until later in the code..

Confused | :confused:

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| theJazzyBrain |
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Nathan Blomquist27-Jun-03 2:02

Nathan Blomquist

27-Jun-03 2:02

You could declare it as on object type and then do some casting later on, when you do decide what it is.

Or you can look to find their nearest common base type (which will always be object at some point at the top of the tree).

Hope this helps, but I couldn't find those types in the MSDN documentation, though I did find the SQLClient namespace.

-Nathan

---------------------------
Hmmm... what's a signature?

theJazzyBrain27-Jun-03 2:32

27-Jun-03 2:32

I thought of that as well,

<br />
private object objConnection;<br />

then you go

<br />
if (isSqlServer)<br />
objConnection = (SqlConnection)objConnection;<br />
else<br />
objConnection = (OleDbConnection)objConnection;<br />
<br />
objConnection.Open();<br />

But the compiler throws an error saing that the type object does not support he Open() method...

hmm...

Then I thought of having both Sql and OleDb connection objects in a Hashtable but again it wont work coz I have to cast them again into the right type in order to extract them from the Hashtable...

Hmmm...

Brain cells dont work well 2day... Confused | :confused:

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| theJazzyBrain |
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Roland Bär27-Jun-03 3:03

27-Jun-03 3:03

I think you have to Cast it each time you call a member of the Object:

<br />
if (isSqlServer)<br />
((SqlConnection)objConnection).Open();<br />
else<br />
((OleDbConnection)objConnection).Open();<br />
<br />

Hope that helps...

Roland

theJazzyBrain27-Jun-03 3:07

27-Jun-03 3:07

I hand't thought of that....

Isn't that though too much overhead for the server?
I have no idea if casting is a heavy job or not...

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| theJazzyBrain |
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leppie27-Jun-03 7:19

leppie

27-Jun-03 7:19

theJazzyBrain wrote:
I have no idea if casting is a heavy job or not...

About 0.0025 ms per cast Poke tongue | ;-P

So no.

leppie ::AllocCPArticle(Generic DFA State Machine for .NET);

Oleksandr Kucherenko27-Jun-03 2:58

Oleksandr Kucherenko

27-Jun-03 2:58

use interfaces!

Good Luck
Alex Kucherenko

theJazzyBrain27-Jun-03 3:04

27-Jun-03 3:04

yeah I just came up with that IDbConnection inteface

or shall I just make an abstract class and then make a class for each DB Client?

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| theJazzyBrain |
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Oleksandr Kucherenko27-Jun-03 3:15

Oleksandr Kucherenko

27-Jun-03 3:15

Only two question:
Is it realy needed to support Sql and OleDb clients at the same time?
You need both dataaccess methods in runtime?

I make my current project using only OleDb... And I can say that i have no performance looses. OleDb give you more kinds of storages that can be used by you.

So... if you still interesting in support of two data access methods then better write own short wrappers... later they can be easily grow to someting more complex.

Good Luck
Alex Kucherenko

theJazzyBrain27-Jun-03 3:23

27-Jun-03 3:23

I see your point,

but, as Microsoft claim, the SqlClient is suppose to be much faster than OleDb when using SQLServer. So I feel that it is important to use it...

Depends always on the application and what performance you are looking for I guess...

But once I getting into the mission to make an object to handle all DB interaction, (and I have the time to do it now) I rather do it now than having to come back in a few months and sort out then...;)

I think that I will make an abstract class and then have a class for each client... This way it is more expandable aswell... Big Grin | :-D

I might share it in an article when I am done.;P Big Grin | :-D

;P

Thank you all anyway for your help!!!...
I am sure that I will be back with more qestions soon... Big Grin | :-D

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| theJazzyBrain |
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Arjan Einbu28-Jun-03 11:43

Arjan Einbu

28-Jun-03 11:43

Nope.
Go for the interface...

theJazzyBrain28-Jun-03 11:59

28-Jun-03 11:59

I dont know how to use it

I will read MSDN...

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| theJazzyBrain |
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Arjan Einbu29-Jun-03 0:37

Arjan Einbu

29-Jun-03 0:37

Like this:

<br />
private IDbConnection objConnection;<br />

objConnection will now take either a SqlConnection or a OleDbConnection object.
(objConnection = new SqlConnection(); or objConnection = new OleDbConnection(); will work equally well...)
The IDbConnection interface has the Open() and Close() methods, so you don't have to do casts to use them...
objConnection.Open();

theJazzyBrain29-Jun-03 0:54