How to write connection string in app.config file dynamicly in c# application??

Answer 1

Hmmm... in that case, let's clarify a few things about your issue:

1. What type of application is this? WPF, WinForm, ASP.NET, Console, Xamarin, etc?

2. Is this application able to connect to the database from your development machine?

3. When running from your client's machine, is the application supposed to connect to the same database used by your development machine or a completely different instance of the database?

4. If this is supposed to connect to a different instance of the database, have you updated the connection string in the client's app.config file accordingly?

5. Have you tested the new connection string outside of the application to make sure it's valid? Example... connect using a database client or creating a DSN connection.

6. If you know your connection string is correct, what error messages are you receiving when attempting to connect from the application?

Answer 2

What do you mean by "dynamically"?

The connection string is statically configured in the app.config (or web.config) and then used at runtime by the code.

This article might help you with the specific syntax to use:

https://www.c-sharpcorner.com/UploadFile/7d3362/various-ways-to-specify-connection-string-in-Asp-Net-web-app/

Answer 3

amit kumar Gupta Your response to #3 doesn't answer the question I was asking.

I'm trying to figure out if the application on your development machine and your client's machine are accessing the same database. Or did you install a new database for the client machine to use?

I also added notes to your last two responses. It also appears you haven't responded to questions #4 and #6.

I'll wait to respond further once I know the answer to question #3.

Answer 4

If I understand correctly. You have a program that uses sql. You are looking to use this program on other PCs. And the connectionstring should be changed according to the user's needs. ok let's do it
1- at first add new project to your solution
2- Add new form. Write this form to receive connection string information from the user and save it in a file
2-in main form on constructor check if this file exists
If there was read file and use this code

var DBConnString = System.Configuration.ConfigurationManager.AppSettings("ConString");

//open connection
var dataContext= new MyDataContext(sDBConnString);

otherwise
Give a message to require the user to enter information

Answer 5

David Carroll 👌👌 Exactly, This is also a good idea. But sometimes you have to hide important and sensitive information like password. In these projects, the file can also be hidden or Information can also be encrypted.

Answer 6

amit kumar Gupta Glad to hear it's working. But don't keep us in suspense. What was the issue?

Answer 7

I'm not sure what you're trying to do. I suppose you can just change the connection string during runtime and save the config value.

Why do you want to change the connection string at runtime? Why not just use the configured connection string?

Answer 8

Sure... looking at the code might help.

Answer 9

Ef or ADO.NET?

Answer 10

hossein B Technically... you can skip the write to file bit. Just use the connection string from memory once fed by the user.

Then he can tweak the string until he can verify connection is successful. 😉👌

Answer 11

Thanks friends for your help
Now it's working fine

Answer 12

Suspence??😆😆😆
It's nothing like suspence friend
If you are interested in application code then I can share complete application code
Can you please give me your email address??

Answer 13

What is your question?
The connection string is a string. You can save it in a variable ?
Do you need to know how to write, the app.config file ?
or how to do it in a secure way ?

Answer 14

But I want change connection string at application first run at another computer

Answer 15

Please help

Answer 16

Sorry man I don't understand I am a fresher and I am trying to build an application to manage a daybook
Application is almost complete but when I am trying to test on a Clint machine application is not connecting to database and I don't know what to do

Answer 17

زه خپله پرې صحي نه پوهېږم وروره نو تاسو ته به څه وښایم!

Answer 18

1 my application is a win form application
2 yes application is able to connect to the database on my development machine
3 no my application is not connecting any instance on Clint machine

Answer 19

5. I am not yet tested a new connection string of the out side application

Edit by David:
amit kumar Gupta I assume you meant to list this as a response to #5. You originally numbered this as 4.

Answer 20

when I configar SQL server instance and machine name on Clint machine as on my machine it work

Edit by David:
amit kumar Gupta You originally numbered this as 6. However, my question for #6 was in regards to providing error messages that can be reviewed.