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 Timer’s 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 don’t see the ToolBar in the Toolbox, click the down arrow next to the General button to scroll down the list • Click the ToolBar’s 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 button’s 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) • In the ToolBarButton Collection Editor, click Add again. ToolBarButton1 is added. In the properties listing for ToolBarButton1, change the button’s 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 • 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 • Double-click the ToolBar control, which opens the ToolBar1_ButtonClick event procedure in the Code Editor. Insert the code in Figure 4-20 • 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 ImageList1’s 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 ToolBar1’s 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\LogonManagerFinal • 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 application’s 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 mdiMain’s 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

15. 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 supervisor’s 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

17. 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

20. 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 mnuViewSupervisorResetExpirationDates_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@fgdt.org, and the password dublinfgdt. His secret question asks for his mother’s 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 Ireland’s 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 LogonManager’s 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 LogonManager’s 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

27. 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

28. Summary • Class library application • Compiles to a DLL (dynamic link library) file • To call a class from another application • Add a reference to the class’s 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