c# 加密和解密相关代码

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

namespace Chapter_03
{
    public partial class ConnectionStringBuilderDialog : Form
    {
        public ConnectionStringBuilderDialog（）
        {
            InitializeComponent（）;
        }

        string _ConnectionString;
        public string ConnectionString { get { return _ConnectionString; } }

        DbProviderFactory _ProviderFactory;
        public DialogResult EditConnectionString（DbProviderFactory ProviderFactory DbConnectionStringBuilder ConnectionStringBuilder）
        {
            _ConnectionString = ConnectionStringBuilder.ConnectionString;
            _ProviderFactory = ProviderFactory;

            propGrid.Selectedobject = ConnectionStringBuilder;
            DialogResult retval = this.ShowDialog（）;

            if （retval == DialogResult.OK）
                _ConnectionString = ConnectionStringBuilder.ConnectionString;

            return retval;
        }

        private void btnTest_Click（object sender EventArgs e）
        {
            try
            {
                this.Cursor = Cursors.WaitCursor;
                using （DbConnection cn = _ProviderFactory.CreateConnection（））
                {
                    DbConnectionStringBuilder bldr = （DbConnectionStringBuilder）propGrid.Selectedobject;
                    cn.ConnectionString = bldr.ConnectionString;
                    cn.Open（）;
                }
                this.Cursor = Cursors.Default;
                MessageBox.Show（“Success!“ “Connection attempt succeeded!“ MessageBoxButtons.OK MessageBoxIcon.Information）;
            }
            catch （Exception ex）
            {
                this.Cursor = Cursors.Default;
                MessageBox.Show（ex.Message “Connection attempt failed!“ MessageBoxButtons.OK MessageBoxIcon.Error）;
            }
            this.Cursor = Cursors.Default;
        }
    }
}