CS 230 Fall 20046                              Assignment 12 – Parallel Arrays                                                   100 points

Assigned: 11/29/2006

Due: 12/08/2006 at the start of class.

Pre-Lab (Do Before Lab):  Bring a new disk. Plan out tasks, objects, and events needed for program. Plan out major pseudocode

Main Assignment:

E-Vote Inc is revising their program to cash in on the electronic voting era.  Your program (though still simplified) has a major improvement over your previous version – you can see a summary of results – with number of votes for each candidate and displaying the winner. Your program still only deals with voting for one office. The program should get from a file (voters.txt) a list of voter Ids and voter names, and display them in a list box.  The program should also get from another file (candidates.txt) a list of candidates and put them in an array of candidates, as well as a list box or combo box. There should also be a parallel array with the number of votes received (which should start out as zero!!! J ). When the user selects a voter  from the voter list box, their info should be displayed in read-only text boxes or in labels. When a user then selects the candidate from the combo box (or list box) AND selects a “Vote” button, acknowledge the vote, write the vote (voterId, name and candidate selected) to a comma-delimited text file for later auditing (add it to those already in the file), update the number of votes received for the appropriate candidate and remove the voter from the list box of eligible voters.  Do NOT allow somebody to vote if they have not BOTH signed in AND picked a candidate. (DO NOT have the vote recorded immediately upon selection in the combo box in case of an inadvertent click). Provide the vote capability, a summary results capability and an exit capability.

Hand in:

• Floppy disk with an entire folder containing all files related to the project.  Please set the name of the project to something other than the default name (WindowsApplication1, …). It is helpful if you use a name that identifies you as well as the assignment (e.g. yourlastname assignment 12). Use Windows to copy the whole folder, instead of trying to “Save As”.
• Print out of your code.

Task Details

• You must use the filenames specified above, so I can easily test a bunch of different programs in a row. Sample files are provided on the assignments page of my www site. In the spirit of thorough testing of programs, you should try other versions of files as well.
• We are still not handling secure access – voters are just selecting themselves off a list.  
• Your program will use parallel arrays of candidates and of the number of votes they receive. You must do this, it is what we are exercising in this assignment.
• DO NOT try to do this using classes. We have not covered them sufficiently yet!!!!!
• In defining the arrays, you can assume that there will be no more than 10 candidates for a position.
• Display voter name and ID for selected voter in separate controls. You will need to separate the info using string capabilities.
• For validation, ensure when the vote button is selected that the voter and candidate have both already been selected.
• After the vote button has been recorded, give the voter some kind of confirmation (e.g. a msgbox) and automatically clear the voter and candidate choices.
• As in Assignment 9:
• Remove the voter from the list box using listboxname.Items.Remove(itemtoremove) where itemtoremove is a string to be removed.
• When you remove the voter from the voter listbox, that will result automatically in a change to the item selected property of the list box, triggering an event. Your event procedure needs to protect against that crashing your program (the selected item will be set to “nothing” which is a built in value – typing it in (nothing) you should see it turn blue.  To test if a selected item is nothing you can do a test checking:  listboxname.SelectedItem is Nothing.
• Summary results capability should provide BOTH: a candidate by candidate list with candidate name and number of votes received (in a rich text box?) AND an indication of the winner’s name (in a read only text box or label?).

Miscellaneous:

• You must turn on Option Strict and Option Explicit

• We have covered procedures and functions – I recommend that you continue to use them whenever helpful (e.g. extracting a line of text from the text in a file).

· MAKE SURE YOUR PROGRAM WORKS!

· Put YOUR NAME, e-mail address, date, and purpose of the program in comments at the beginning of the program.

· You MUST include comments that explain your program in order to get full credit.

· Remember to use meaningful variable names, and indent to show the structure of the program (VB usually does this correctly).

· Put your name on the form as a Label or as part of the form title.

· Try to use good user interface design. Make clear what user needs to do and what the answers mean.