/// <summary>
/// Event handler for key presses in ISBNtextBox
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ISBNTextBox_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Enter) //if enter key is pressed, attempt to add the book to the BookListView
{
AddBookToList();
ISBNTextBox.Text = string.Empty;
ISBNTextBox.Focus();
}
}
/// <summary>
/// Verifies the user's ISBN entry which must be a 10 or 13 digit code.
/// If ISBN is valid, matches a Book in the collection, and has copies available for checkout,
/// add the Book to be shown in BooksListView.
/// </summary>
private void AddBookToList()
{
//Edit the user input to remove non-digit characters (spaces, etc.)
StringBuilder sb = new StringBuilder();
foreach (char c in ISBNTextBox.Text)
{
if (Char.IsDigit(c)) //check if character is a digit
{
sb.Append(c);
}
else if (Char.IsLetter(c)) //if a letter is in the code, not valid.
{
ErrorLabel.Content = "ISBN is not valid, must be a 10 or 13 digit code.";
return;
}
}
string token = sb.ToString(); //get the resulting isbn
if (token.Length != 10 && token.Length != 13) //if isbn length is incorrect, return
{
ErrorLabel.Content = "ISBN is not valid, must be a 10 or 13 digit code";
return;
}
Book b = controller.SearchISBN(token); //isbn is valid, retrieve book from collection
if (b == null) //book not found
{
ErrorLabel.Content = "Book not found. Please verify the ISBN.";
return;
}
else //book found
{
if (b.CopiesAvailable == 0) //no available copies
{
ErrorLabel.Content = "No copy of this book available for check out.";
return;
}
else //Add book to ObservableCollection and set focus to ISBNTextBox
{
books.Add(b);
ISBNTextBox.Focus();
CheckOutButton.IsEnabled = true;
}
}
}
// save button clicked
private void SaveButton_Click(object sender, EventArgs e)
{
if (TitleTextBox.ForeColor != Color.Red && AuthorTextBox.ForeColor != Color.Red &&
ISBNTextBox.ForeColor != Color.Red && PriceTextBox.ForeColor != Color.Red)
{
// adding new book
if (addNewBookMode)
{
DialogResult save = MessageBox.Show("Do you want to save the book?", "Add New Book", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
if (save == DialogResult.Yes)
{
scmd = new SqlCommand("select count(*) from Books where (ISBN = @isbn)", connection);
scmd.Parameters.AddWithValue("@isbn", ISBNTextBox.Text);
connection.Open();
int exists = (int)scmd.ExecuteScalar(); // check if entered isnb is unique
connection.Close();
if (exists == 0)
{
scmd = new SqlCommand("insert into Books(Title, Author, ISBN, Price) Values(@title, @author, @isbn, @price)", connection);
connection.Open();
scmd.Parameters.AddWithValue("@title", TitleTextBox.Text);
scmd.Parameters.AddWithValue("@author", AuthorTextBox.Text);
scmd.Parameters.AddWithValue("@isbn", ISBNTextBox.Text);
scmd.Parameters.AddWithValue("@price", PriceTextBox.Text);
scmd.ExecuteNonQuery();
connection.Close();
MessageBox.Show("The Book Was Added Successfully.");
DisplayBooks(); // refresh combobox values
ResetAll();
BooksComboBox.Enabled = true;
}
else
{
MessageBox.Show("Provided ISBN code already exists in the database.", "Invalid ISBN Code", MessageBoxButtons.OK, MessageBoxIcon.Error);
ISBNTextBox.Focus();
}
}
}
// updating existing book
if (updateBookMode)
{
DialogResult update = MessageBox.Show("Do you want to update the book?", "Update Existing Book", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
if (update == DialogResult.Yes)
{
string cmdText = "UPDATE Books SET Title = @title, Author = @author, Price = @price WHERE ISBN = @isbn";
scmd = new SqlCommand(cmdText, connection);
connection.Open();
scmd.Parameters.AddWithValue("@title", TitleTextBox.Text);
scmd.Parameters.AddWithValue("@author", AuthorTextBox.Text);
scmd.Parameters.AddWithValue("@isbn", ISBNTextBox.Text);
scmd.Parameters.AddWithValue("@price", PriceTextBox.Text);
scmd.ExecuteNonQuery();
connection.Close();
MessageBox.Show("The Book Was Updated Successfully.");
DisplayBooks(); // refresh combobox values
ResetAll();
}
}
}
else
{
MessageBox.Show("Make sure you have provided valid inputs for all the fields", "Invalid Input Provided", MessageBoxButtons.OK, MessageBoxIcon.Error);
if (TitleTextBox.ForeColor == Color.Red)
{
TitleTextBox.Focus();
}
if (AuthorTextBox.ForeColor == Color.Red)
{
AuthorTextBox.Focus();
}
if (ISBNTextBox.ForeColor == Color.Red)
{
ISBNTextBox.Focus();
}
if (PriceTextBox.ForeColor == Color.Red)
{
PriceTextBox.Focus();
}
}
}