C# modify config file

Question

I was wondering if you can point me to a reference  for  the  following:
After a C#.net application obtains  the windows user  name and password, I want to pass this information to sql server  using  windows authenication. Right now the connection string information  is hard code in the app.conf  file. How would you replace the code that is currenly in  app.conf  files?

Answer 1

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;

namespace Retrieving_excel_data_to_combobox
{
    public partial class Form1 : Form
    {
        public OleDbConnection con;
        public void pintu(string s)
        {
            con = new OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; " + "data source='" + s + " '; " + "Extended Properties=Excel 8.0;");

        }
        public OleDbCommand com;
        public DataSet ds;
        public OleDbDataAdapter oledbda;
        public DataTable dt;
        public string str;

        public Form1()
        {
            InitializeComponent();
        }

        private void btnbrowse_Click(object sender, EventArgs e)
        {
            OpenFileDialog openfiledialog1 = new OpenFileDialog();
            openfiledialog1.ShowDialog();
            openfiledialog1.Filter = "allfiles|*.xls";
            TextBox1.Text = openfiledialog1.FileName;

        }

       

        private void btndisplay_Click(object sender, EventArgs e)
        {
            pintu(TextBox1.Text);
            try
            {
                con.Open();
                str = "select * from [sheet1$]";
                com = new OleDbCommand(str, con);
                ds = new DataSet();
                oledbda = new OleDbDataAdapter(com);
                oledbda.Fill(ds, "[sheet1$]");
                con.Close();
                DataGridView1.DataSource = ds;
                DataGridView1.DataMember = "[sheet1$]";
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

        }
    }
}

Answer 2

I got the answer guys..

 private void button1_Click(object sender, EventArgs e)

        {

            OpenFileDialog ofImport = new OpenFileDialog();

            ofImport.Title = "Select file";

            ofImport.InitialDirectory = @"c:\";

            ofImport.FileName = openFileDialog1.FileName;

            ofImport.Filter = "Excel Sheet(*.xlsx)|*.xlsx|All Files(*.*)|*.*";

            ofImport.FilterIndex = 1;

            ofImport.RestoreDirectory = true;

            if (ofImport.ShowDialog() == DialogResult.OK)

            {

                string path = System.IO.Path.GetFullPath(ofImport.FileName);

                string query = "SELECT * FROM [Sheet1$]";

                OleDbConnection conn = new OleDbConnection();

                conn.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + ofImport.FileName + ";Extended Properties=" + "\"Excel 12.0 Xml;HDR=YES;IMEX=1\"";

                OleDbDataAdapter adapter = new OleDbDataAdapter(query, conn);

                DataSet dataSet = new DataSet();

                adapter.Fill(dataSet);

                dataGridView1.DataSource = dataSet.Tables[0];

            }

            else

            {

                ofImport.Dispose();

            }   

        }