👀 Views: 59 💬 Answers: 1 📅 Created: 2025-06-06

sql-server connection-string winforms visual-studio C#

I'm having difficulty configuring the connection string for my WinForms application in Visual Studio 2022 to connect to a local SQL Server instance. I am using .NET 5 and have the SQL Server Express edition installed. Despite several attempts, I keep getting the behavior: `A network-related or instance-specific behavior occurred while establishing a connection to SQL Server`. Here's the connection string I've been using in my `appsettings.json`: ```json { "ConnectionStrings": { "DefaultConnection": "Server=localhost;Database=MyDatabase;Trusted_Connection=True;" } } ``` I’ve checked that the SQL Server service is running and that I can connect via SQL Server Management Studio using the same credentials. I've also tried switching `Trusted_Connection=True` to `User ID=myUser;Password=myPassword;`. However, this just leads to a different behavior: `Login failed for user 'myUser'.` In my code, I'm trying to retrieve the connection string like this: ```csharp var connectionString = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString; ``` I've also ensured that the `System.Configuration.ConfigurationManager` package is installed. Still, I get the same connection-related behavior. Could there be an scenario with how I’m formatting the connection string or any configurations in Visual Studio that could be affecting the connection? Any insights would be greatly appreciated!