CheckListBox中的词典需要帮助

Question

The code is ac# Windows Forms Application done on Visual Studio 2012, the aim of the task is to use dictionary in a GUI to add, remove, and search for books.

I have laid out my gui application, it contains 4 buttons, 2 textfields, 2 checkboxlists,and then a few labels to explain what they do.

button3 is supposed to activate a search using ISBN. (user enters ISBN in textbox1 , then all books that contain a part of that will be matched)

Here is my form code

Dictionary<string, Book> library = new Dictionary<string, Book>();
public Form1()
{
    InitializeComponent();
    button1.Text = "Add Book";
    button2.Text = "Remove Book";
    button3.Text = "Search Using ISBN";
    button4.Text = "Search Using Title";
    label1.Text = "Enter ISBN below";
    label2.Text = "Enter Title below";
    label3.Text = "Tick boxes on the left display if a book is loaned or not";
    label4.Text = "All books found after search";
}

public void Update()
{
    checkedListBox1.Items.Clear();
    foreach (var pair in library)
    {
        checkedListBox1.Items.Add(pair.Value);
    }
}
private void button1_Click(object sender, EventArgs e) //Add Button
{
    if (textBox1.Text != "" && textBox2.Text != "")
    {
        library[textBox1.Text] = new Book(textBox1.Text, textBox2.Text);
        Update();
    }
}
private void button2_Click(object sender, EventArgs e) //Remove Button
{
        library.Remove(textBox1.Text);
        Update();
}
private void button3_Click(object sender, EventArgs e) //ISBN Search Button
{
}

}

And the Book class.

class Book
{
    private String isbn;
    private string title
    private Boolean onloan = false;
    public Book(string isbn, string title)
    {
        this.isbn = isbn;
        this.title = title;
    }
    public string ISBN
    {
        get { return isbn; }
        set { isbn = value; }
    }
    public string Title
    {
        get { return title; }
        set { title = value; }
    }
    override public String ToString()
    {
        return this.ISBN + "        " + this.Title;
    }
} 

I am struggling with button3 . I enter a partial bit of an ISBN in textbox1 , then click the button, this should then look through the dictionary and if it finds any book that matches it will display them in the other checklistbox2 .

I have tried quite a few methods in displaying them in to checklistbox2 but when I click the button nothing appears in checklistbox2 .

I'm really stumped on how to do this.

I have tried.

EDIT:

I have found out where I was going wrong, there was nothing wrong with my logic, sadly my form.design.cs did not contain

this.button3.Click += new System.EventHandler(this.button3_Click);

I have now fixed this and everything works as it should.

Answer 1

You can use a lambda expression

private void button3_Click(object sender, EventArgs e) //ISBN Search Button
{
    checkedListBox2.Items.Add(_library.First(i => i.Key == textBox1.Text).Value);
}

Answer 2

in my Form1.Designer.cs I had not included

this.button3.Click += new System.EventHandler(this.button3_Click);

I added this and my code works as normal, I used

private void button3_Click(object sender, EventArgs e) //ISBN Search Button
{
    checkedListBox2.Items.Clear(); //clears list on click

    foreach (var pair in library)
    {
        if (pair.Key.Contains(textBox1.Text))
        {
            checkedListBox2.Items.Add(pair.Value);
        }
    }  
}

Thank you everyone who commented to help me.