C# Discussion Boards - CodeProject

Winform support in Windows service

23-Jan-22 6:49

mynametaken wrote:
bw.Write(data);
bw.Write(data.Length);

That is not the same as the following. The order is different.

mynametaken wrote:
dos.writeInt(data.length);
dos.write(data);

Member 1260803929-Dec-21 23:59

Member 12608039

29-Dec-21 23:59

Hello everyone, I have a problem.
I have a project on Winform and it works great, now the customer wants to run this project as a Windows service.
The peculiarity of the project, I use a library (presumably written in C ++) that Winform uses, before calling the library I can translate the service into Windows, and I cannot translate the part where the library works. Is there a way to start a service with Winform support? I am considering all the options right up to the use of paid softs.
The system will be in Sign Out mode most of the time.

OriginalGriff30-Dec-21 0:27

OriginalGriff

30-Dec-21 0:27

Services cannot have any Winforms support: they a=cannot have any interface or methods of interaction with the user.

What you would have to do is start a user process (a Winforms project) that communicates with the service and provides it with instructions.

You can't add Winforms to a service at all!

"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!

Member 1260803930-Dec-21 1:28

Member 12608039

30-Dec-21 1:28

I managed to start from the Winform service but it doesn't work when the user is logged out

OriginalGriff30-Dec-21 2:08

OriginalGriff

30-Dec-21 2:08

Member 12608039 wrote:
it doesn't work when the user is logged out

Of course it won't - that's what services are for, and they don't have any user interface at all! Applications aren't running while a user is logged out, but services are.
To have a user interface, you need a user - and services are designer to run with or without a logged in user. Hence, you need a separate Winforms project to communicate with your service when there is a user there, and the service runs "alone" when the user isn't logged in.

Dynamically change int from a string

#realJSOP30-Dec-21 1:20

#realJSOP

30-Dec-21 1:20

You need to break out the core functionality into its own library assembly, and then create a windows service project that references that assembly. The windows service project can be compiled as a regular console app to make debugging easier, and you can also make the winform app reference that assembly (also easier to debug).

".45 ACP - because shooting twice is just silly" - JSOP, 2010
-----
You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
-----
When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

Matte Matik29-Dec-21 12:02

Matte Matik

29-Dec-21 12:02

Hello,
Please i would like to know how to declare an int from a dynamic given string.
Like this:

for (int i = 500; i >= 350; i--)
{
string combine = "offset_y_bar_" + i;

{
int "combine" = i;
}
}

Re: Dynamically change int from a string

Dave Kreskowiak29-Dec-21 12:36

Dave Kreskowiak

29-Dec-21 12:36

You can't. C# is a compiled language, not interpreted.

If you think you need to do something like this, you should be looking at an array instead.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.

Dave Kreskowiak

Re: Dynamically change int from a string

OriginalGriff29-Dec-21 21:53

OriginalGriff

29-Dec-21 21:53

You are going to have to be a lot clearer about exactly what you want to do - you can't have "quoted strings" as variable names.

If you want to be able to associate a string "name" with a value and access it later by the name, then probably what you want to do is look at a Dictionary:

Dictionary<string, int> items = new Dictionary<string, int>();
for (int i = 500; i >= 350; i--)
    {
    string combine = $"offset_y_bar_{i}";
    items[combine] = i;
    }
Console.WriteLine(items["offset_y_bar_421"]);

C# Entity Framework : how to generate custom automatic numbers

Fidele Okito27-Dec-21 4:50

Re: C# Entity Framework : how to generate custom automatic numbers

27-Dec-21 4:50

Good afternoon,

Please, I m trying to generate a customized automatic numbers using entity framework.
The number is a combination of multiple columns from a table:

table1 (next_id int, prefix_text varch(5), table_name varchar(100))

in the table2( id int, invoice_number varchar(20))

The custom automatic number is invoice_number=(prefix_text)+' '+ (next_id+1) + ' _ '+ Current_year.

I tried to google but nothing. I m trying to use the triggers and also user defined function but I m feeling it not the best way.

Thank you in advance
F.O

Gerry Schmitz27-Dec-21 5:16

Re: C# Entity Framework : how to generate custom automatic numbers

27-Dec-21 5:16

Creating "meaningful" primary keys is usually considered a "bad" design decision for any number of reasons. At "report time" (or for searching), you can do anything you want.

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

Fidele Okito27-Dec-21 5:32

Re: C# Entity Framework : how to generate custom automatic numbers

27-Dec-21 5:32

Thank you for your answer, the invoice number is not the primary key. it is just to display on the report. is there another way to implement.

regards,
FO

Gerry Schmitz27-Dec-21 6:45

Re: C# Entity Framework : how to generate custom automatic numbers

27-Dec-21 6:45

(prefix_text)+' '+ (next_id+1) + ' _ '+ Current_year.

Why can't you do that at report time?

Store the individual fields in the db record as needed; not their concatenation.

Fidele Okito27-Dec-21 7:55

Re: C# Entity Framework : how to generate custom automatic numbers

27-Dec-21 7:55

Thank you so much for your time. Let me explore that option.
best regards
FO

#realJSOP28-Dec-21 0:24

#realJSOP

28-Dec-21 0:24

You could use a datetime field's number of seconds as the "automatic number". Even in a moderately busy system, that would pretty much always be unique. When coupled with a row ID in a clustered primary key, duplicates will not be allowed, so Bob's your uncle.

EDIT ================================

If you're going to down-vote my answer, tell me why.

modified 29-Dec-21 6:01am.

Re: C# Entity Framework : how to generate custom automatic numbers

jschell29-Dec-21 7:17

Re: C# Entity Framework : how to generate custom automatic numbers

29-Dec-21 7:17

I am not really in agreement with the other comments since they somehow seem to be drilling down on a 'primary' key even though I see nothing in your request that suggests that.

Your posting should focus on creating an 'invoice number'
It will need to have the following
1. Be unique
2. Be human readable
3. Be small enough that humans will not be annoyed by it.

Presumably the 'prefix_text' is unique by itself. It does not rely on the 'table_name'. If that is not the case then the uniqueness constraint for the invoice number will not be met by the form that you posted.

I would suggest that you do not use underscores. A separator is ok but use a dash since it tends to be more obvious. However you can also consider the dash as being a display character only. So for example credit card numbers often use a dash but the numbers are actually the only part of the actual id. So your UI could take it with dashes but remove it for searches. And in the database you store it without the dashes.

Without the separator the format must be fixed however. So it is a design decision.

Volume of the business and generation of the code, now and for some time into the future, impacts how you might want to do this. If you are producing say 100 of them a day then it is easier than if you are producing 100 million in a day.

There might be a security concern if you generate numbers that are easily guessed. So for example if you use the current date along with an incrementing number then it is easy to guess valid invoice numbers. This also is a matter for how the business works. It isn't much of a concern if there are other authentication factors used to limit access to the invoices.

I don't see anything conceptually wrong with your basic idea although I would format the id (pad zeros to the left.)

Fidele Okito wrote:
using entity framework.

I am guessing that this in fact is your real problem.

What you want to do is just use native SQL. Myself I would probably use a stored proc but you can do it with SQL in the application.

You need the following in a transaction. This is pseudo code but the idea is basically sound.

declare @lastId int;
update table1 set next_id = next_id + 1 where prefix_text='xxx' and table_name='fff';
select @lastId = next_id from table1 where prefix_text='xxx' and table_name='fff';
insert into table2 (invoice_number) values('xxx' + '-' + @lastId + '-' + ...);
select @lastId;

The last part of that returns the newest id to your application. Not needed if that is not something that is needed at that point.

The transaction is necessary to insure uniqueness.

Gerry Schmitz29-Dec-21 15:22

Re: C# Entity Framework : how to generate custom automatic numbers

29-Dec-21 15:22

"Drilling"? "Primary Key" was mentioned in passing because that is typically a "novice" mistake; on the other hand, it's amazing how something so simple can be made so complicated; particularly since every party to the transaction has to now quote and enter and reference it when it means absolutely nothing to them.

Every client and vendor has their own "numbering system"; why it never caught on in the "stationary" dept when it came to "invoice pads" will always be a mystery. Maybe because it was so easy to tell when one was missing in the sequence.

Actually, use a blockchain.

modified 29-Dec-21 21:33pm.

Peter_in_278029-Dec-21 15:32

Peter_in_2780

29-Dec-21 15:32

"Invoice pads" ... reminds me of my first job many many moons ago. I committed the cardinal sin of using the last requisition in the book for something other than another requisition book. Chaos ensued for the department. Blush | :O

Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012

Re: C# Entity Framework : how to generate custom automatic numbers

Gerry Schmitz29-Dec-21 15:54

Re: C# Entity Framework : how to generate custom automatic numbers

29-Dec-21 15:54

You broke the chain!

jschell30-Dec-21 7:31

Re: C# Entity Framework : how to generate custom automatic numbers

30-Dec-21 7:31

Gerry Schmitz wrote:
"Drilling"? "Primary Key" was mentioned in passing because that is typically a "novice" mistake; on the other hand, it's amazing how something so simple can be made so complicated; particularly since every party to the transaction has to now quote and enter and reference it when it means absolutely nothing to them.

Not sure what that means.

Invoices mean a lot to many people that actually look at the invoice. The invoice number is the name of the invoice. Just that. And certainly much better than attempting to describe the invoice by time, date, contents. And even those might be ambiguous in some situations. For example if a duplicate is created. In those case the invoice number is the only thing that allows one to determine that there are two different ones.

Gerry Schmitz30-Dec-21 9:23

Re: C# Entity Framework : how to generate custom automatic numbers

30-Dec-21 9:23

It means what it means because you used the word "drilling" and "primary key".

I also don't see anything to indicate that you have actually worked with AP, AR and ERP systems and integrated them.

jschell23-Jan-22 7:01

Re: C# Entity Framework : how to generate custom automatic numbers

23-Jan-22 7:01

Gerry Schmitz wrote:
I also don't see anything to indicate that you have actually worked with AP, AR and ERP systems and integrated them.

First of course nothing in the question suggests this has anything to do with integrating systems. It very much looks like creating a value that people, not systems, would consume.

Second your comment is nothing but an attempt to denigrate and doesn't address anything I said or what was said in the original thread.

Third I didn't see you present any credentials that suggested you are an expert on that specific subject.

Fourth as far as credentials go I have been working with databases for 40 years. That includes as DBA, DBA Team lead and designing from scratch for several companies. And it does include large migrations and mitigations on large systems using disparate database systems.

Gerry Schmitz wrote:
what it means because you used the word "drilling" and "primary key".

No idea what that means. You are the one that specifically first mentioned "primary key" in your first post in response to the initial question.

So yes it was appropriate for me to address that comment in terms of differentiating the need for a displayable invoice number and a "primary key" since there was no indication that they intended to use is as a "primary key".

Fidele Okito30-Dec-21 3:14

Re: C# Entity Framework : how to generate custom automatic numbers

30-Dec-21 3:14

Dear jschell,

Thank you for your comment which is helpful alot.
I was thinking to create a user defined function(tsql) :

create function NextInvoiceValue()
return nvarchar(30)
Begin
declare @lastId int;
declare @valueinvoice nvarchar(30)

--update table1 set next_id = next_id + 1 where prefix_text='xxx' and table_name='fff';
select @lastId = next_id from table1 where prefix_text='xxx' and table_name='fff';
--insert into table2 (invoice_number) values('xxx' + '-' + @lastId + '-' + ...);
set @valueinvoice='xxx' + '-' + (@lastId +1) + '-' + ...;
return @valueinvoice;

end

This function will be used on create table table2 (..., invoicenum nvarchar(30) not null default dbo.NextInvoiceValue()...)

and the last step is to create a trigger(after insert) on table2, this trigger will execute the update statement :

update table1 set next_id = next_id + 1 where prefix_text='xxx' and table_name='fff';

I m wondering if this will make sense for daily traffic of 100 000 insertions

Thank you again
FO

jschell30-Dec-21 7:26