ASP.Net/Language Basics/Class Definition

Материал из .Net Framework эксперт
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Constructor with parameter (C#)

<%@ page Language="c#" runat="server" %>
<script runat="server">
public class Book
{
  private string title;
  private int isbn;
  private decimal price;
  public Book(string newTitle, int newIsbn)
  {
    title = newTitle;
    isbn = newIsbn;
  }
  public string TitleInfo
  {
     get 
     {
        return title + " <i>[ISBN: " + isbn + "]</i>";
     }
  }
  public string Title
  {
    get 
    {
       return title;
    }
  }
  public int Isbn
  {
    get 
    {
      return isbn;
    }
  }
  public decimal Price
  {
    get 
    {
      return price;
    }
    set 
    {
      price = value;
    }
  }
}
  void Page_Load()
  {
    Book MyBook = new Book("Beginning ASP.NET 1.0 with C#", 1861007345);
    Response.Write("<b>new book "MyBook" created.</b>");
    MyBook.Price = 39.99m;
    Response.Write("<br/>Title info: " + MyBook.TitleInfo);
    Response.Write("<br/>Price: $" + MyBook.Price + "<br/>");
    Book AnotherBook = new Book("Professional ASP.NET 1.0 SE", 1861007035);
    Response.Write("<b>new book "AnotherBook" created.</b>");
    AnotherBook.Price = 59.99m;
    Response.Write("<br/>Title info: " + AnotherBook.TitleInfo);
    Response.Write("<br/>Price: $" + AnotherBook.Price + "<br/>");
  }
</script>



Define a class and display its value (C#)

<%@ Page Language="C#" %>
<script runat="server">
  public class Person
  {
    private string  _Name;
    private int _Age;
    private string  _EyeColor;
    public Person() {
    }
    public string  Name {
      get {
        return _Name;
      }
      set {
        _Name = value;
      }
    }
    public int Age {
      get {
        return _Age;
      }
      set {
        _Age = value;
      }
    }
    public string EyeColor {
      get {
        return _EyeColor;
      }
      set {
        _EyeColor = value;
      }
    }
  }

  void Page_Load(object Sender, EventArgs E) {
    Person p = new Person();
    p.Name = "Joe";
    p.Age = 25;
    p.EyeColor = "Blue";
    Name.Text = p.Name;
    Age.Text = p.Age.ToString();
    EyeColor.Text = p.EyeColor;
  }
</script>
<html>
<head>
</head>
<body>
    <form runat="server">
      Name: <asp:Label runat="server" id="Name" /><br />
      Age:  <asp:Label runat="server" id="Age" /><br />
      Eye Color: <asp:Label runat="server" id="EyeColor" />
    </form>
</body>
</html>



Define and use class: property (C#)

<%@ page Language="c#" runat="server" %>
<script runat="server">
public class Book
{
  private string title;
  private int isbn;
  private decimal price;
  public Book()
  {
    title = "Book";
    isbn = 099999999999;
  }
  public string TitleInfo
  {
     get 
     {
        return title + " <i>[ISBN: " + isbn + "]</i>";
     }
  }
  public string Title
  {
    get 
    {
       return title;
    }
  }
  public int Isbn
  {
    get 
    {
      return isbn;
    }
  }
  public decimal Price
  {
    get 
    {
      return price;
    }
    set 
    {
      price = value;
    }
  }
}
  void Page_Load()
  {
    Book MyBook = new Book();
    Response.Write("<b>new book "MyBook" created.</b>");
    MyBook.Price = 39.99m;
    Response.Write("<br/>Title info: " + MyBook.TitleInfo);
    Response.Write("<br/>Price: $" + MyBook.Price + "<br/>");
  }
</script>



Define two classes (C#)

<%@ page language="C#" runat="server" Debug="true"%>
<script runat="server">

  public class Key
  {
    private int shape;
    public Key(int newshape)
    {
      shape = newshape;
    }
    public int Shape
    {
      get
      {
        return shape;
      }
    }
  }
    
    public class Car
  {
    private string color;
    private int gear;
    private int ignition;
    private bool engineRunning;
    private static int count = 0;
    public Car(int IgnitionShape)
    {  
      color = "Cold gray steel";
      ignition = IgnitionShape;
      count += 1;
    }
    public static int Count
    {
      get
      {
        return count;
      }
    }
    public string Color
    {
      get
      {
        return color;
      }
      set
      {
        color = value;
      }
    }
    public int Gear
    {
      get
      {
        return gear;
      }
    }
    public string IsRunning  
    {
      get
      {
        if (engineRunning)
        {
          return "The engine is running.";
        }
        else
        {
          return "The engine is not running.";
        }
      }
    }
    public void ChangeGear(int direction)
    {
      if (direction < 0) gear -= 1;
      if (direction > 0) gear += 1;
      if (gear > 5) gear = 5;
      if (gear < -1) gear = -1;
    }
    
    public void ChangeGear(string direction)
    {
      
      if (direction == "down")
      {
        ChangeGear(-1);
      }
      if (direction == "up")
      {
        ChangeGear(+1);
      }
      
    }
    public void Ignition(Key IgnitionKey)
    {
      if (IgnitionKey.Shape == ignition) engineRunning = true;
    }
    public void EngineOff()
    {
      engineRunning = false;
    }
  }
    
    public void Page_Load()
  {
    Key AlexKey = new Key(0987654321);
    Key RobKey = new Key(1861005040);
    Key MyKey = new Key(1234567890);
    Car MyCar = new Car(1234567890);
    Response.Write("<b>New object "MyCar" created.</b>");

    Response.Write("<br/>Color: " + MyCar.Color);
    Response.Write("<br/>Gear: " + MyCar.Gear);
    MyCar.Color = "Black";
    MyCar.ChangeGear(+1);
    Response.Write("<br/><b>Properties updated.</b>");
    Response.Write("<br/>New color: " + MyCar.Color);
    Response.Write("<br/>New gear: " + MyCar.Gear);
    MyCar.ChangeGear("up");
    Response.Write("<br/><b>Shifted "up" one gear.</b>");
    Response.Write("<br/>New gear: " + MyCar.Gear);
    Response.Write("<hr/>Attempting to start MyCar with AlexKey: ");
    MyCar.Ignition(AlexKey);
    Response.Write(MyCar.IsRunning);
    Response.Write("<hr/>Attempting to start MyCar with RobKey: ");
    MyCar.Ignition(RobKey);
    Response.Write(MyCar.IsRunning);
    Response.Write("<hr/>Attempting to start MyCar with MyKey: ");
    MyCar.Ignition(MyKey);
    Response.Write(MyCar.IsRunning);
    Response.Write("<br/>Attempting to stop MyCar: ");
    MyCar.EngineOff();
    Response.Write(MyCar.IsRunning);
  }
</script>