Class Libraries Project

1
Class Libraries Project
2
Objectives

• Convert a Windows Forms application into a class
  library
• Build a class library, and create a solution with
  multiple projects
• Incorporate a component into a class library
  project, and use the component to exchange
  parameter data with a client program
• Plan for the completion of the LogonManagerFinal
  application, including the MDI form, child forms,
  and calls to two class library projects

3
Converting a Windows Forms Application into a
Class Library

• To convert FigWelcome from Tut01 into a reusable
  splash screen
• In Windows Explorer, copy the FigWelcome folder
  from the Tut01 folder and paste it into the Tut04
  folder. Then, in Visual Studio .NET, open the
  FigWelcome solution from the Tut04 folder, and
  open frmWelcome in the Form Designer
• Drop a Timer control from the Toolbox onto
  frmWelcome (it will appear in a tray beneath the
  form), set its Enabled property to True, set its
  Interval property to 3000 (that is, three
  seconds), and insert the following statement into
  the Timers Tick event procedure Me.Dispose().
  Run the FigWelcome program to see that it
  terminates after three seconds
• Delete btnClose and the btnClose_Click event
  procedures. Run the FigWelcome program again. In
  Windows Explorer, in the Tut04\FigWelcome\bin
  folder, delete FigWelcome.exe
• Right-click the project name, FigWelcome, and
  click Properties. If necessary, navigate through
  the FigWelcome Property Pages, to the General tab
  of Common Properties, and change the setting in
  the Output type combo box to Class Library. Click
  OK

4
frmWelcome in the IDE
5
Incorporating FigWelcome into Other Programs

• To incorporate FigWelcome into other programs
• Add a reference to the FigWelcome Class Library
• Insert the Imports FigWelcome statement before
  the class declaration of the startup form or
  module in the client application
• Insert the Dim declaration and ShowDialog()
  method shown in Step 5 of the previous exercise
  into the Sub Main() procedure, the Sub New()
  procedure (after the InitializeComponent() call),
  or the Form_Load event procedure of the client

6
Building The Logon Class Library

• How do you pass parameters between the calling
  (client) program and the called (class library)
  program?
• Case of the LogonManager application
• The calling program (LogonManager) should call
  the Logon program
• Calling program should receive an indication that
  the user successfully logged on (or did not)
• Parameter may be passed to a procedure ByRef or
  ByVal
• When passed ByRef
• Address where the variable is stored in the
  calling routine is passed to the called routine
  (function or method)
• When passed ByVal
• Value (of the literal, variable, constant, or
  expression) is passed, rather than an address
  where that value is stored

7
Adding a ToolBar Control

• To add a ToolBar control to a new application
• Start a new Visual Basic .NET Windows application
  called SampleToolBar in the Tut04 folder. Put a
  MainMenu control on Form1 with three entries
  Exit, Change Message, and Hide Message. Name
  these menu items mnuExit, mnuChange, and mnuHide
  respectively. Drag a large Label control onto the
  form, set its BackColor property to yellow, its
  Text property to nothing, its TextAlign property
  to MiddleCenter, and its Dock property to Top
• Drag a ToolBar control onto the form. If you
  dont see the ToolBar in the Toolbox, click the
  down arrow next to the General button to scroll
  down the list
• Click the ToolBars Buttons property, then click
  the Collections setting
• In the ToolBarButton Collection Editor, click
  Add. ToolBarButton1 is added. In the properties
  listing for ToolBarButton1, change the buttons
  Name property to tbrBtnExit, and change the Text
  property to Exit. Type the following message in
  the ToolTipText property This terminates the
  program

8
Adding a ToolBar Control (Continued)

1. In the ToolBarButton Collection Editor, click Add
   again. ToolBarButton1 is added. In the properties
   listing for ToolBarButton1, change the buttons
   Name property to tbrBtnChangeLabel, and change
   the Text property to Change Message. Type the
   following message in the ToolTipText property
   Click here to change and show the message
2. In the ToolBarButton Collection Editor, click
   Add. ToolBarButton1 is added. Change its Name
   property to tbrBtnHideLabel, and change the Text
   property to Hide Message. Type the following
   message in the ToolTipText property Click here
   to hide the message. Click OK
3. Double-click the ToolBar control, which opens the
   ToolBar1_ButtonClick event procedure in the Code
   Editor. Insert the code in Figure 4-20
4. Run the SampleToolBar program, and click the
   Change Message button

9
Adding an ImageList Component

• To add an ImageList to SampleToolBar
• Copy and paste three images (icons, bitmaps,
  tifs, or gifs) into the SampleToolBar solutions
  folder (VB.NET\Student\Tut04\SampleToolBar)
• Drag an ImageList component from the Toolbox onto
  Form1
• Click ImageList1s Images property, and then
  click Collections in the settings box
• In the Image Collection Editor, click Add. In the
  Open dialog box, navigate to the SampleToolBar
  folder, and add one of the image files you have
  copied there
• Click ToolBar1. Set its ImageList property to
  ImageList1. Now click ToolBar1s Buttons
  Collection property. In the ToolBarButton
  Collection Editor, click tbrBtnExit. Under
  tbrBtnExit properties, click ImageIndex. Select
  one of the three images (0, 1, or 2)
• Run the SampleToolBar program to ensure that the
  images appear properly on the toolbar buttons at
  runtime

10
Adding an OpenFileDialog Control

• OpenFileDialog control
• Purpose is to designate a file to be opened for
  input
• Used by the mnuFileRestore_Click() procedure
• Has almost all the same properties, appearance,
  and behavior as the SaveFileDialog control

11
Setting up and Planning the LogonManagerFinal
Application

• To set up the LogonManagerFinal application
• Create a new folder called VB.NET\Student\Tut04\Lo
  gonManagerFinal
• Into this new folder, copy the contents of either
  the VB.NET\Student\Tut03\LogonManagerDraft folder
  or the completed LogonManagerDraft application
  folder you obtain from your instructor
• Click File Open Solution, and open the
  LogonManagerDraft.sln (solution) file. In
  Solution Explorer, click Solution
  LogonManagerDraft (1 project). In the Solution
  Properties window, click the solution name, and
  change it to LogonManager. In Solution Explorer,
  click the project name, LogonManagerDraft. Then
  in Project Properties, change the name of the
  project to LogonManager
• Run the LogonManager project from the IDE to make
  sure that it still works correctly
• In Windows Explorer, navigate to the
  LogonManagerFinal folder. Verify that the name of
  the solution file has been changed to
  LogonManager.sln, and the name of the project is
  now LogonManager.vbproj

12
Identifying Tasks to Complete LogonManager

• Complete the mdiMain GUI
• Add ToolBar and ImageList controls
• Enhance applications GUI
• Write new menu click event procedures for menu
  items that were under construction at end of
  Tutorial 3
• Incorporate calls to the Logon application in
• mnuViewExistingUser_Click()
• mnuViewSupervisorLogon_Click()
• Display the splash screen (FigWelcome) at startup

13
Completing the mdiMain GUI

• To add an image list and toolbar to mdiMain
• Add an ImageList control to mdiMain. Add any
  three icons (.ico files) to its Images Collection
• Add a ToolBar control to mdiMain. Set its
  ImageList property to ImageList1. In the Buttons
  property, click Collection. In the ToolBarButton
  Collection Editor, add three ToolBarButtons, and
  set the appropriate Text and ImageIndex property
  for each button, as suggested by Figure 4-26. Set
  the ToolTipText property to Fill out the
  application form to become a user, Update/verify
  your user information and change your password,
  and Logon as the system supervisor, respectively
• To open the ToolBar1_ButtonClick event procedure,
  in mdiMains Code window, select ToolBar1 from
  the Class Name combo box at the top left. Then
  select ButtonClick from the Method Name combo box
  at the top right
• Recall that you can use a Select Case control
  structure to differentiate among ToolBarButton
  controls. Add the code shown in Figure 4-27
• Run the LogonManagerFinal application to see that
  it still works as it did at the end of Tutorial 3
  and to verify that the new toolbar buttons work
  as advertised

14
Implementing a RadioCheck

• To implement the RadioCheck in front of the
  Accept New Users menu item
• Insert the mnuViewSupervisor_Select() procedure
  shown in Figure 4-28
• Code uses a local Boolean variable,
  blnNewUserPending, initialized to False, to
  indicate the presence of at least one new user
  record
• When an N record is encountered
• Boolean variable is set to True

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ToolBar1_ButtonClick() Event Procedure
16
Programming Procedures on the File Menu

• To create and test the backup and restore
  procedures
• Begin by dragging a SaveFileDialog control and an
  OpenFileDialog control onto mdiMain
• Insert the code shown in Figure 4-29 into
  mnuFileBackup_Click()
• Program the mnuFileRestore_Click() procedure, as
  shown in Figure 4-30
• Run the LogonManagerFinal application. Log on as
  the system supervisor (recall that the
  supervisors e-mail address is 1 and the password
  is SUPERVISOR). Then click File Backup, and
  save the Users file in the Temp folder as
  Users.bak. Then click File Restore, and restore
  the Users file you have just backed up. Exit the
  program and return to the IDE

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Code for mnuFileBackup_Click()
18
Code for mnuFileRestore()_Click
19
Programming Procedures on the View Menu

• To (partially) program the remaining stubs in the
  View menu
• Open the mnuViewExistingUser_Click() procedure.
  Insert the code shown in Figure 4-31
• Open mnuViewSupervisorEditUserInfo_Click(). Type
  the code shown in Figure 4-32
• Run the LogonManagerFinal program to verify that
  the procedures you have just created work
  correctly. Exit the program and return to the IDE
• Add a new form named frmViewAll to the
  LogonManager project. Set its WindowState
  property to Maximized. Add a ListBox control, and
  set its Dock property to Fill
• Insert the code shown in Figure 4-33 into the
  frmViewAll_Load() procedure

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Programming Procedures on the View Menu
(Continued)

• In mdiMain, in mnuViewSupervisorViewAllUsers_Click
  (), insert code shown in Figure 4-35 to maximize
  mdiMain and show the child form
• Run the LogonManagerFinal program, logon as the
  supervisor, and view the child form. Exit the
  program and return to the IDE
• Type the code into the mnuViewSupervisorResetExpir
  ationDates_Click() event procedure shown in
  Figure 4-36
• Run the LogonManagerFinal application again. Log
  on as the supervisor, and click View Supervisor
  View All Users. Note the password expiration
  dates for each active user. Now click View
  Supervisor Reset Expiration Dates. Then click
  View Supervisor View All Users again, and
  note the revised password expiration dates for
  all active users except the supervisor. Exit the
  application and return to the IDE

21
Disabling Controls for Multiple Users and Purposes

• To disable user-editable controls in frmUser when
  the Accept New Users menu item has been selected
• In frmUser, insert a new procedure called
  DisableControls(). In this procedure, disable all
  of the user-editable controls on frmUser
  (TextBoxes, ComboBox, CheckBox, and RadioButtons)
• In mdiMain, in the mnuViewSupervisorAcceptNewUsers
  _Click() procedure, insert the following
  statement before showing the child form
  frmUserTemp.DisableControls()
• Run the LogonManagerFinal program. Create a new
  user named Dublin Ireland, with an e-mail address
  of Dublin_at_fgdt.org, and the password dublinfgdt.
  His secret question asks for his mothers maiden
  name, and the answer is Casey. Submit the New
  User
• Click View Supervisor. A RadioCheck appears in
  front of Accept New Users. Log on as the
  supervisor. Click Accept New Users. Dublin
  Irelands record appears. Verify that all the
  user-editable controls have been disabled. Click
  Accept. Click View Supervisor. The RadioCheck
  no longer appears in front of Accept New Users
• Exit the application and return to the IDE

22
Adding a Call to the Logon Application

• To insert the Logon application into LogonManager
  
• In Solution Explorer, add a reference to the
  Logon.dll in the LogonManagers References by
  right-clicking References in Solution Explorer,
  then clicking Add Reference. In the Add Reference
  dialog box, click the Projects tab. Browse to
  find the Logon.dll (in VB.NET\Student\Tut04\Logon\
  bin), and click OK
• In the Code window for mdiMain, insert the
  following statement before the Public Class
  mdiMain statement Imports Logon
• Replace the stub code with a call to the Logon
  application in the mnuViewSupervisorLogon_Click()
  procedure as shown in Figure 4-37
• Navigate to mnuViewExistingUser_Click(), and add
  the code shown in Figure 4-38 at the beginning of
  the procedure, replacing the InputBox function
  call. In this case, the user need not be a
  supervisor
• Run the program, checking that the two calls to
  the Logon application work as advertised. Exit
  the program and return to the IDE

23
Code for mnuViewSupervisorLogon_Click()
24
Calling Logon from mnuViewExistingUser_Click()
25
Adding the Call to the FigWelcome Splash Screen

• To insert the FigWelcome splash screen into
  LogonManager
• In Solution Explorer, add a reference to the
  FigWelcome.dll in the LogonManagers References
• In the Code window for mdiMain, insert the
  following statement before the Public Class
  mdiMain declaration Imports FigWelcome
• Navigate to the Windows Form Designer generated
  code section, in Sub New(), and insert the
  following after the InitializeComponent() method
  call
• Dim MyWelcome As New frmWelcome()
• MyWelcome.ShowDialog()
• Run the LogonManager program

26
Understanding the Power of a Class Library

• To implement a change to Logon
• Open the Logon solution, open frmLogon in the
  Form Designer, and set the BackgroundImage
  property to the bitmap file Gone Fishing.bmp.
  Then run the TryLogon project, which calls Logon
  and causes it to compile, updating its DLL
• Run LogonManager.exe from the Start menu or from
  Windows Explorer. Click View Existing User to
  invoke Logon
• Open LogonManager in the IDE, if necessary, and
  run it from within the IDE. This calls the new
  DLL for the class library. When Logon is invoked,
  it appears with the new background. Exit the
  application, and exit Visual Studio .NET
• Now run LogonManager once more from the Start
  menu or from Windows Explorer

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Summary

• ToolBar control
• Often incorporated into a form
• ImageList control
• Contains a collection of images
• OpenFileDialog control
• Allows the user to specify a file to be opened
  for input

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Summary

• Class library application
• Compiles to a DLL (dynamic link library) file
• To call a class from another application
• Add a reference to the classs DLL in the calling
  application
• To make the members of a class available without
  qualification
• Use the Imports statement
• Component
• Can be defined in a class library
• Can contain procedures with parameters passed
  from a calling routine
• Efficiency of OOP
• Becomes obvious during program maintenance