How to connect to a database in PostgreSQL from a C# application?

Question

PostgreSQL

In the application, I connect using the NPGSQL class
connectionStr = $"Server=localhost;Port=1488;User={LoginText.Text.Trim(' ')};Password={PasswordText.Text.Trim(' ')};Database=PrivateBD; ";
npgSqlConnection = new NpgsqlConnection(connectionStr);
try
{
npgSqlConnection.Open();
MessageBox.Show("Connected!", "Hurrah", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
Then it gives an error that the base I specified in the line does not exist!
Severity: FATAL Code: 3D000
But the same line only with a database named postgres establishes a connection with a bang. What could be the problem? The error appears on any database created by me in pdAdmin!

Answer 1

Take out the connection string in the config file, also check the user in the specified database, it can help.