Class Libraries - C# Discussion Boards

Re: updating DataBase Problem (delete row)

Ami8-Dec-07 9:01

Ami

8-Dec-07 9:01

can you be more specific ?
what should i set?

Re: updating DataBase Problem (delete row)

Giorgi Dalakishvili8-Dec-07 9:16

Giorgi Dalakishvili

8-Dec-07 9:16

ClientsAdapter.DeleteCommand property

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Using SQL Server Database

AndyHug8-Dec-07 8:17

AndyHug

8-Dec-07 8:17

I'm new to C#,but I used VB.NET a lot ... This prject I have to do in C# and I allready have problems connecting to my SQL SERVER Database.

I put an combobox into my form which I want to link to some records in my database ...

So combobox.Datasource = ... Add Project DataSource ... Database ... Connection to my SQL SERVER Database ...

I saved the connection string as TSConnectionString ... Selected the tables and views I need from my database ...

and Visual Studio has created the files ... TSDataSet.xsd ( TSDataSet.Designer.cs , TSDataSet.xsc , TSDataSet.xss )

I mention that the combobox.DataSource property is still empty and the program can compile succesfully ... for now

When I come back to fill combobox.Datasource with TSDataSet namely tSDataSetBindingSource when i try to compile the

next error message pops up :

Error 1 The type name 'TSDataSet' does not exist in the type 'TSales.TSales'

... and the code behind this error is :

this.tSDataSet = new TSales.TSDataSet(); --------------- here is the error

this.tSDataSetBindingSource = new System.Windows.Forms.BindingSource(this.components);
this.panTop.SuspendLayout();
((System.ComponentModel.ISupportInitialize)(this.tSDataSet)).BeginInit();
((System.ComponentModel.ISupportInitialize)(this.tSDataSetBindingSource)).BeginInit();
this.SuspendLayout();

Remember though I wrote above that Visual Studio creates those 4 files (TSDataSet.xsd , TSDataSet.Designer.cs , TSDataSet.xsc , TSDataSet.xss ) and puts them in Solution Explorer

So my question is ... how come there is no tSales.TSDataSet ?

and what should I do to link those records to that combobox and other records to other controls in my form

Thank you

CheckBoxList

anupamwb8-Dec-07 7:50

anupamwb

8-Dec-07 7:50

hello everybody....
I want to know How to enable/disable an item in an checkboxlist ?
i need that urgent.
I follow below procedure.
CheckBoxList.item[0]. ===I did not get enabled option .how to get that enable option.
thanks

Re: CheckBoxList

Ravi Bhavnani8-Dec-07 8:00

Ravi Bhavnani

8-Dec-07 8:00

anupamwb wrote:
how to get that enable option.

You need to use the list box's CheckedIndices[^] or CheckedItems[^] properties.

Also see the SetItemCheckState()[^] method.

/ravi

This is your brain on Celcius
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Re: CheckBoxList

Xmen Real 8-Dec-07 16:41

Xmen Real

8-Dec-07 16:41

CheckBoxList.SetItemChecked(0, true);

hope it will help

Becoming Programmer...

Check multiple rows in datagridview without losing selection

Hynkar8-Dec-07 7:46

Hynkar

8-Dec-07 7:46

Hi,

I have a datagridview with a checkbox column and multiselect set to true. I want the user to be able to select multiple rows and check/uncheck them with a single click on one of the selected checkboxes. (like you can set the status flag for multiple emails in outlook). But unfortunately when you click on a checkbox only the row this checkbox is in becomes selected destroying the current selection.

Is there a way to keep the selection?

Cheers
Andreas

Class Libraries

Poolee8-Dec-07 7:30

Poolee

8-Dec-07 7:30

Hi everyone

I'm still quite new to Object Oriented Programming, so please forgive me for this newbie question.

I'm building an application with a main form and a couple of sub-forms. There is also an assocated service that goes with the application.

- Should the class library only code that doesn't deal directly with processing events on the forms, or just methods that are used more than once?
- Should each form then have its own class library, or should I create a single class library for the whole application and the service to use?
- Or should I be creating separate class libraries based on their usage to enable later reuse of the class library?

I've trawled through MSDN and found some best practices but they don't mention what to do in the above scenarios... I gotta say I'm leaning towards the last point here, but I really don't know... Frown | :(

Any help you gurus can provide would be greatly appreciated!

Cheers
Paul

One day I want to be a code monkey. Right now, I'm more like a code amoeba...

Re: Class Libraries

Ravi Bhavnani8-Dec-07 8:29

Ravi Bhavnani

8-Dec-07 8:29

Poolee wrote:
Or should I be creating separate class libraries based on their usage to enable later reuse of the class library?

Bingo!

/ravi

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Re: Class Libraries

Poolee8-Dec-07 9:21

Poolee

8-Dec-07 9:21

Ok, thanks Ravi.

But what about methods purely related to doing something related to the form, but doesn't fall into a particular category? Should I be keeping those with the form class's code?

Cheers
Paul

One day I want to be a code monkey. Right now, I'm more like a code amoeba...

Re: Class Libraries

Ravi Bhavnani8-Dec-07 9:23

Ravi Bhavnani

8-Dec-07 9:23

Yes. If you think the methods could be used by more than one form, you may want to encapsulate them in a utility class.

/ravi

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Re: Class Libraries

Poolee8-Dec-07 9:28

Poolee

8-Dec-07 9:28

Awesome, thanks for your help Ravi!! Big Grin | :-D

Cheers
Paul

One day I want to be a code monkey. Right now, I'm more like a code amoeba...

selectively passing different classes to a function - C#

karthikde19808-Dec-07 7:19

karthikde1980

8-Dec-07 7:19

Hello,

I have a doubt in Inheritance. Can you help me?

I have a baseclass "common" with 3 child classes child1,child2,child3

I have another base class "state" with its 3 child classes state1, state2, state3.

I have a function named xyz() in all the 3 childclasses of "common", which I want to move to the parent class common.

The function xyz( ) in child1 uses the class state1 inside the function, creates object for state1.

The function xyz( ) in child2 uses the class state2 and creates object for state2.

The function xyz( ) in child3 uses the class state3 and creates object for state3.

The function xyz() is same, that is, repeated in all of the 3 childclasses, the only difference is usage of classes state1, state2, state3.

In this case how can I move this xyz() function into the base class "common", so that all the 3 child classes can access the function from the parent class...

I am unable to receive state1, state2 or state3 selectively as argument for the function xyz() at the baseclass "common", depending upon which child class (child1,child or child3) calls this function. Passing the baseclass "state" in place of state1, state2, state3 does not work as the child classes contain additionaly required variables not present in "state".

Is it necessary that I have to use Generic Inheritance....
can throw some light on it?

with best regards
Karthik

Re: selectively passing different classes to a function - C#

karthikde19808-Dec-07 8:49

karthikde1980

8-Dec-07 8:49

Hello everybody .... any help with my question? ... Thanks in advance.

Karthik

Re: selectively passing different classes to a function - C#

Christian Graus8-Dec-07 9:07

Christian Graus

8-Dec-07 9:07

I almost didn't answer you because at first glance, I thought you had an answer already. Help on this site is free. Especially on weekends, it's not always fast, it can be, but you just need to wait, so long as your question is visible, this sort of post doesn't really help.

Christian Graus - Microsoft MVP - C++

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Re: selectively passing different classes to a function - C#

Christian Graus8-Dec-07 9:05

Christian Graus

8-Dec-07 9:05

I am having trouble folloowing this.

I *think* what you need to do is write code in the base class like this:

class common
{
public void xyz(state s)

}

then in your derived classes do this:

class child1
{
public override void xyz(state s)
{
state1 state = s as state1;
if (state != null)
{
// interact with it
}
else
{
// do whatever you want when the state is not the type you hoped for
}
}
}

Having a pair of class heirarchies that are so tightly coupled makes me wonder if the state should be a property of the base class, instantiated as the right type in the derived class, and accessed from the childx class.

Re: selectively passing different classes to a function - C#

karthikde19808-Dec-07 10:05

karthikde1980

8-Dec-07 10:05

Dear Mr. Graus,

Thanks for ur reply. Actually, the function xyz() is presently located in the three child classes child1, child2 & child3 and working alright. What I want to do is, to move this xyz() function into the base class "common", so that all the 3 child classes can access the function from the baseclass.

When I have physically moved the function xyz() to the "common" baseclass, the child classes child1, child2 & child3 would have no problem calling this function in the baseclass and pass the appropriate class (that is, one of state1, state2 or state3) as argument, depending on who is calling the function. But the problem arises when I try to create the objects of the class state1 or state2 or state3 inside the xyz() function in the baseclass.

for example, If I create object for state1 inside the Function, it will work only for state1 but will not work for state2 or state3 as arguments, called from child2 or child3 respectively. How can I write a code in the baseclass that accepts any one of state1, state2 or state3 as arguments?

Thanks for your reply and help.

Greetings,
Karthik

Re: selectively passing different classes to a function - C#

Christian Graus8-Dec-07 10:36

Christian Graus

8-Dec-07 10:36

karthikde1980 wrote:
How can I write a code in the baseclass that accepts any one of state1, state2 or state3 as arguments?

You can do one of two things

1 - provide three methods that take the three derived objects
2 - use the one method that takes the base, and use the 'as' keyword in the manner I showed you to work out which it is. But again, if you need to do this, then your design is probably broken. So any of the three derived classes could be used as parameters in any of the three derived classes that impliment xyz ? I think you need to work on making your base class work so that it's interface works for all three derived objects, so you don't need to work out which it is.

TCP/IP Sockets

half-life8-Dec-07 6:42

half-life

8-Dec-07 6:42

HI,

im tring to send and receive Msg in TCP/IP

i have the Sockets on both sides

the problems begins when i call the BeginReceive (...) Method

While in Debug every thing looks fine all the Msg arrives

(the other sends let say : 100 Msg under a For Stat)

but when i run the Exe only the last Msg Arrives

Any Idea

Have Fun
Never forget it

Re: TCP/IP Sockets

Kristian Sixhøj8-Dec-07 6:45

Kristian Sixhøj

8-Dec-07 6:45

Could we see some code please?

Kristian Sixhoej

"Failure is not an option" - Gene Kranz

Re: TCP/IP Sockets

half-life8-Dec-07 6:55

half-life

8-Dec-07 6:55

this is the main BeginReceive function
the OnReceive does just server.EndReceive

server/client = new Socket(AddressFamily.InterNetwork,<br />
                    SocketType.Stream,<br />
                    ProtocolType.Tcp);<br />
<br />
<br />
server.BeginReceive(buffer, <br />
//buffer is a gloabal variant - byte [1024] array<br />
                    0, <br />
                    1024, <br />
                    SocketFlags.None, <br />
                    new AsyncCallback(OnSend), <br />
                    null);<br />
<br />
while in the client that sends all the info has : <br />
<br />
<br />
client.BeginSend(buffer, <br />
                    0, <br />
                    1024, <br />
                    SocketFlags.None, <br />
                    new AsyncCallback(OnSend), <br />
                    null);

and there is the :

<br />
for(int i=0;i<100;i++)<br />
{<br />
 SendMessage(); // this method calls the BeginSend in the  client<br />
}<br />

When i Debug in the SendMessgae() i see the Message sends
and chech in the compute next to me (Agagin in debug)
that the server has come to where :

server.BeginReceive(buffer, <br />
                    0, <br />
                    1024, <br />
                    SocketFlags.None, <br />
                    new AsyncCallback(OnReceive), <br />
                    null);

and indid it comes and the Msg Arrives into the buffer

BUT in Exe only the last Msg is recievd

Have Fun
Never forget it

Re: TCP/IP Sockets [modified]

Kristian Sixhøj8-Dec-07 7:07

Kristian Sixhøj

8-Dec-07 7:07

Try putting it in a do while loop like this:

do
{
    server.BeginReceive(buffer, 0, 1024, SocketFlags.None,
    new AsyncCallback(OnReceive), null);
} while (server.BeginReceive() != null);

I'm not sure if the code above will work, but try it out.

EDIT: If you know the number of messages - like you do in this case - you could do this:

// here, 100 is the number of messages
for (int msg = 0; msg <= 100)
{
    server.BeginReceive(buffer, 0, 1024, SocketFlags.None,
    new AsyncCallback(OnReceive), null);
}

Kristian Sixhoej

"Failure is not an option" - Gene Kranz

modified on Saturday, December 08, 2007 1:18:44 PM

Re: TCP/IP Sockets

half-life8-Dec-07 8:46

half-life

8-Dec-07 8:46

THANKS

it did'nt work

but THANKS anyway
i'll try to start from the begining Smile | :)

Have Fun
Never forget it

Getting Data from DataReader

tr_thorn8-Dec-07 2:55

tr_thorn

8-Dec-07 2:55

Hi how can i get from oledb or sql data reader data to messagebox or a Textbox ?

Can someone gimme an example.

Re: Getting Data from DataReader

Ennis Ray Lynch, Jr.8-Dec-07 3:12

Ennis Ray Lynch, Jr.

8-Dec-07 3:12

Don't use the code below but:

someTextBox.Text = (string)someDataReader[0];

Really there are a lot of intermediary steps that need to be taken before something like this can be done in production code.

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