sdk/samples/all in on code/Visual Studio 2008/CSWinFormSingleInstanceApp/MainForm.cs

   1 /****************************** Module Header ******************************\
   2 * Module Name:  MainForm.cs
   3 * Project:      CSWinFormSingleInstanceApp
   4 * Copyright (c) Microsoft Corporation.
   5 *
   6 * The  sample demonstrates how to achieve the goal that only
   7 * one instance of the application is allowed in Windows Forms application..
   8 *
   9 * This source is subject to the Microsoft Public License.
  10 * See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  11 * All other rights reserved.
  12 *
  13 * History:
  14 * * 8/31/2009 3:00 PM Bruce Zhou Created
  15 \***************************************************************************/
  16
  17 using System;
  18 using System.Collections.Generic;
  19 using System.ComponentModel;
  20 using System.Data;
  21 using System.Drawing;
  22 using System.Linq;
  23 using System.Text;
  24 using System.Windows.Forms;
  25
  26 namespace CSWinFormSingleInstanceApp
  27 {
  28     public partial class MainForm : Form
  29     {
  30         #region fields
  31         LoginForm loginEntry = new LoginForm();
  32         string loginMsg = "";
  33         event EventHandler LoginMsgChanged;
  34         #endregion
  35
  36         #region Properties
  37         public string LoginMsg
  38         {
  39             get { return loginMsg; }
  40             set
  41             {
  42                 if (value != loginMsg)
  43                 {
  44                     loginMsg = value;
  45                     OnLoginMsgChanged(EventArgs.Empty);
  46                 }
  47             }
  48         }
  49         #endregion
  50
  51         #region Constructor
  52         public MainForm()
  53         {
  54             InitializeComponent();
  55             this.Load += new EventHandler(MainForm_Load);
  56             this.StartPosition = FormStartPosition.CenterScreen;
  57
  58         }
  59         #endregion
  60
  61         #region EventHandlers
  62         void MainForm_Load(object sender, EventArgs e)
  63         {
  64             //show Login dialog
  65             loginEntry.ShowDialog();
  66             //display welcome message
  67             DisplayWelcomeMessage();
  68             //bind Text of lableUserStatus to LoginMsg property.
  69             this.labelUserStatus.DataBindings.Add("Text", this, "LoginMsg");
  70         }
  71         private void buttonLogoff_Click(object sender, EventArgs e)
  72         {
  73             GlobleData.IsUserLoggedIn = false;
  74             LoginMsg = "User Successfully logged off";
  75
  76             this.Visible = false;
  77             loginEntry = new LoginForm();
  78             if (loginEntry.ShowDialog() == DialogResult.OK)
  79             {
  80                 if (this.Visible == false && GlobleData.IsUserLoggedIn)
  81                 {
  82                     this.Visible = true;
  83                 }
  84                 LoginMsg = "User Successfully logged in";
  85             }
  86         }
  87         #endregion
  88
  89         #region HelperMethods
  90         void DisplayWelcomeMessage()
  91         {
  92             string welcomeMsg = "Welcome to codeplex:" + GlobleData.UserName;
  93             this.labelWelcomeMsg.Text = welcomeMsg;
  94             LoginMsg ="User Successfully logged in";
  95
  96         }
  97
  98         void OnLoginMsgChanged(EventArgs e)
  99         {
 100             if (LoginMsgChanged != null)
 101             {
 102                 LoginMsgChanged(this, e);
 103             }
 104         }
 105         #endregion
 106     }
 107 }