回收 Windows Forms C# 中的连接字符串

Question

I'm trying to reuse a connection string created from a DataGridView. I can't seem to translate the value in the Settings.settings file to a usable connection string. Any ideas of what the Connection_String SHOULD look like?

Error:

Format of the initialization string does not conform to specification starting at index 0.

Code:

 // This fills the gridview
                this.loanacctTableAdapter.FillBy(this.innovate_Loan_ServicingDataSet.loanacct, ((decimal)(System.Convert.ChangeType(acctrefnoToolStripTextBox.Text, typeof(decimal)))));

// This tries to use the same connection
 Connection_String = SpecialSetting.ConnectionString.ToString();
 Command = "SELECT acctrefno FROM loanacct WHERE acctrefno = " + AcctrefnoToolStripTextBox.Text + "";
SqlConnection Conn = new SqlConnection(Connection_String);
SqlCommand Comm1 = new SqlCommand(Command, Conn);
Conn.Open();
SqlDataReader DR1 = Comm1.ExecuteReader();
if (DR1.Read())
   {
   textBox1.Text = DR1.GetValue(0).ToString();
   textBox1.ReadOnly = true;
   }
Conn.Close();

Settings.Designer.cs

        [global::System.Configuration.ApplicationScopedSettingAttribute()]
        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
        [global::System.Configuration.SpecialSettingAttribute(global::System.Configuration.SpecialSetting.ConnectionString)]
        [global::System.Configuration.DefaultSettingValueAttribute("Data Source=ILSVUPGRADE01;Initial Catalog=Innovate_Loan_Servicing;Integrated Secu" +
            "rity=True")]
        public string Innovate_Loan_ServicingConnectionString {
            get {
                return ((string)(this["Innovate_Loan_ServicingConnectionString"]));

Answer 1

ConnectionString is simply a String. I suggest to use the SqlConnectionStringBuilder Class. It makes it much easier to create a valid connection string.

You can get the full ConnectionString then with .ToString()

Answer 2

The solution ended up being the difference between Windows Forms and ASP.NET. I needed to find the configuration in the Settings.settings file and drill down. Windows forms stores the connection string as "Properties.Settings.Default. name of connection here.ToString(); The command and connection can then be set simply. ASP.NET sets the connection string under ConfigurationSettings.AppSettings("myConnectionString").

My code ended up looking like this.

string Connection_String = Properties.Settings.Default.Innovate_Loan_ServicingConnectionString.ToString();
string Command = "SELECT acctrefno, loan_number, [shortname], [loan_group_no] FROM loanacct WHERE acctrefno = " + acctrefnoToolStripTextBox.Text + "";
SqlConnection Conn = new SqlConnection(Connection_String);
SqlCommand Comm1 = new SqlCommand(Command, Conn);
Conn.Open();
SqlDataReader DR1 = Comm1.ExecuteReader();
if (DR1.Read())

etc.