Programming Assignment 6 Instructions
Adapted from Introduction
to Programming Using Visual Basic 2012, 9/E, David I. Schneider.
The figures below show the
output of a Visual Basic program that displays information about Bachelor
degrees conferred in 1981 and 2006, the percentage of change, and a histogram
for the 2006 data. Create this program
using arrays. The program should allow a
user to display any of these tables as an option and to quit as a fourth
option. The first table is ordered
alphabetically by field of study. The
second table is ordered by decreasing percentages, and the last table is
ordered by increasing number of degrees.
Deliverables:
1.
Write a Visual Basic program
that displays the information below.
2.
Do not prompt the user to enter
the degree information.
3.
Use the information below to
populate your arrays.
4.
Use a DataGridView control to
display the data.
5.
Order the data as described
above.
6.
Use appropriate software
development guidelines, such as clearing the grid before populating it with new
data when a button is clicked and including a title on the form.
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Programming Assignment 7 Instructions
Adapted from Introduction
to Programming Using Visual Basic 2012, 9/E, David I. Schneider.
Create and Maintain
Telephone Directories
Write a Visual Basic
program to create and maintain telephone directories. Each telephone directory should be contained
in a separate text file. In addition, a
file named Directories.txt should hold the names of the telephone
directories. At any time, names of all
the telephone directories should be displayed in a list box. After a telephone directory is selected, it
becomes the current phone directory. The
following buttons should be available.
a.
Create a new telephone
directory. (The filename should be provided by an input dialog box.) A new text file should be created for the
directory, and the name of the new directory should be added to the
Directories.txt file. The Phone
Directories listbox should immediately be refreshed to reflect the new
directory, and the new directory should be automatically seleted from the
listbox. Note that this selection should
trigger the procedure that sets the current directory and updates the contents
of the current directory textbox. Also
note that the list of directories is displayed in ascending order in the
listbox.
b.
Add a listing (as given in
textboxes) to the end of the current phone directory. This action should update the text file
containing the listings of the current directory and refresh the grid to
display the newly added listing.
c.
Delete a name (as specified in
the “Name” text box) from the current phone directory. This action should update the text file
containing the listings of the current directory. As is good software development practice, you
should prompt the user with a messagebox that allows him to confirm the
deletion before any permanent action is taken to delete the entry from the
file. The grid should also refresh to
show the removal of the listing.
d.
Display the names and phone
numbers in the current phone directory.
(Note that the listings are displayed in ascending order in the table.)
Design your form as
depicted in the diagram below.
Helpful hints:
1.
The text files needed for this
assignment should be placed in the bin\debug folder of the project.
2.
When the form opens, populate
the directories listbox with the names of the directories.
3.
Use an array and
IO.ReadAllLines to populate the array with the list of directories.
4. Use
the StreamWriterin conjunction with IO.File.AppendText and IO.File.CreateText
to append new directories and create new text files. (Note: You will need to
use the WriteLine method to write the name of the new file to Directories.txt.)
5. When
the user clicks the Create a New Phone Directory button, prompt him to enter
the name using an InputBox. If the user
fails to enter a name, display a message to him (i.e. “Invalid directory
name”), and do not proceed to create a new directory. If the operation is successful, make the new
directory the current directory.
6.
Before adding a new directory,
make sure it doesn’t already exist. You may find it helpful to use
Array.IndexOf in your check.
7.
To display the contents of the
directories file, use a LINQ query. Loop
over all of the items in the query using a For each statement to populate the
listbox.
8.
Before displaying the contents
of the directories file, make sure the file exists first. You will need to use the IO.File.Exists
method in your check.
9.
Use good programming practices
by clearing the listbox and table before refreshing them when a change is made
that affects their contents.
10. Remember
to close the files after accessing them.
11. To
remove a listing from a directory, you may find this code helpful as it selects
only those records in the file that are not
the one the user wants to remove. The
code should then write the results of this query back to the file:
Dim query = From
line InIO.File.ReadAllLines(fileName)
Let name
= line.Split(","c)(0)
LetphoneNum
= line.Split(","c)(1)
Where
name <>txtName.Text
Select name &","&phoneNum
IO.File.WriteAllLines(fileName,
query.ToArray)
12. Use
a DataViewGrid control to display the contents of a specific directory.
13. Include
appropriate error checking (i.e. check for blank names, phone numbers, etc.)
14. Use
appropriate naming conventions for all controls.
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