ASP.NET Tutorial/Collections/Generics — различия между версиями

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Текущая версия на 11:57, 26 мая 2010

A generic Stack class (C#)

<%@ Page Language="C#" %>
    
<script runat="server">
    void Page_Load(object sender, EventArgs e)
    {
        Stack<string> myStack = new Stack<string>();
        myStack.Push("A");
        myStack.Push("B");
        myStack.Push("C");
    
        Array myArray;
        myArray = myStack.ToArray();
    
        foreach (string item in myArray)
        {
             Label1.Text += item + "<br />";
        }
    }
</script>
 
    
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Label runat="server" ID="Label1"></asp:Label>
    </div>
    </form>
</body>
</html>


A generic Stack class using integers (C#)

<%@ Page Language="VB" %>
    
<script runat="server">
    void Page_Load(object sender, EventArgs e)
    {
        Stack<int> myStack = new Stack<int>();
        myStack.Push(5);
        myStack.Push(3);
        myStack.Push(10);
    
        Array myArray;
        myArray = myStack.ToArray();
    
        int x = 0;
        foreach (int item in myArray)
        {
            x += item;
        }
    
        Label1.Text = x.ToString();
    }
</script>


A generic Stack class using integers (VB)

<%@ Page Language="VB" %>
    
<script runat="server">
    Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim myStack As New Stack(Of Integer)
        myStack.Push(5)
        myStack.Push(3)
        myStack.Push(10)
    
        Dim myArray As Array
        myArray = myStack.ToArray()
    
        Dim x As Integer = 0
        For Each item As Integer In myArray
            x += item
        Next
    
        Label1.Text = x.ToString()
    End Sub
</script>
    
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Label runat="server" ID="Label1"></asp:Label>
    </div>
    </form>
</body>
</html>


A generic Stack class (VB)

<%@ Page Language="VB" %>
    
<script runat="server">
    Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim myStack As New System.Collections.Generic.Stack(Of String)
        myStack.Push("A")
        myStack.Push("B")
        myStack.Push("C")
    
        Dim myArray As Array
        myArray = myStack.ToArray()
    
        For Each item As String In myArray
           Label1.Text += item & "<br />"
        Next
     End Sub
</script>
    
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Label runat="server" ID="Label1"></asp:Label>
    </div>
    </form>
</body>
</html>


Creating a list of Person objects using generics (C#)

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    </form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Collections;
using System.Collections.Generic; 
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Person scott = new Person("A", "D");
        Person bill = new Person("B", "E");
        Person srini = new Person("C", "F");
        List<Person> people = new List<Person>(); 
        people.Add(scott);
        people.Add(bill);
        people.Add(srini);
        foreach (Person p in people)
        {
            Response.Write(p.FullName + "<BR/>");
        }
        for (int i = 0; i < people.Count; i++)
        {
            Response.Write(people[i].FullName + "<BR/>");
        }
    }
}
public class Person : IComparable
{
    string FirstName;
    string LastName;
    public Person(string first, string last)
    {
        FirstName = first;
        LastName = last;
    }
    public string FullName
    {
        get
        {
            return FirstName + " " + LastName;
        }
    }
    int IComparable.rupareTo(object obj)
    {
        Person p2 = obj as Person;
        if (p2 == null) throw new ArgumentException("Object is not a Person!");
        int lastNameResult = this.LastName.rupareTo(p2.LastName);
        if (lastNameResult == 0)
        {
            int firstNameResult = this.FirstName.rupareTo(p2.FirstName);
            return firstNameResult;
        }
        else
        {
            return lastNameResult;
        }
    }
}


Creating a list of Person objects using generics (VB)

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    </form>
</body>
</html>
File: Default.aspx.vb
Imports System
Imports System.Collections
Imports System.Collections.Generic
Imports Microsoft.VisualBasic
Public Class Person
    Implements IComparable
    Dim FirstName As String
    Dim LastName As String
    Public Sub New(ByVal First As String, ByVal Last As String)
        FirstName = First
        LastName = Last
    End Sub
    Public ReadOnly Property FullName() As String
        Get
            Return FirstName & " " & LastName
        End Get
    End Property
    Public Function CompareTo(ByVal obj As Object) _
        As Integer Implements IComparable.rupareTo
        If Not TypeOf (obj) Is Person Then
            Throw New ArgumentException("Object is not a Person!")
        End If
        Dim p2 As Person = CType(obj, Person)
        Dim lastNameResult As Integer = Me.LastName.rupareTo(p2.LastName)
        If lastNameResult = 0 Then
            Dim firstNameResult As Integer = Me.FirstName.rupareTo(p2.FirstName)
            Return firstNameResult
        Else
            Return lastNameResult
        End If
    End Function
End Class
Partial Class _Default
    Inherits System.Web.UI.Page
    Protected Sub Page_Load(ByVal sender As Object, _
            ByVal e As System.EventArgs) Handles Me.Load
        Dim scott As New Person("A", "F")
        Dim bill As New Person("B", "E")
        Dim srini As New Person("C", "D")
        Dim people As New List(Of Person)
        people.Add(scott)
        people.Add(bill)
        people.Add(srini)
        For Each p As Person In people
            Response.Write(p.FullName & "<BR/>")
        Next
        For i As Integer = 0 To people.Count - 1
            Response.Write(people(i).FullName & "<BR/>")
        Next
    End Sub
End Class


Generic collections

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="TestGenericCollections" Debug="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Test Generic Collections</title>
</head>
<body>
    <form id="form1" runat="server">
   <div id="container">
      <h1>Test Generic Collections</h1>
      This is a tester for our generic collection class.
      <asp:ListBox ID="lboxCustomers" runat="server" />
      <br />Retrieved Customer via index: 
      <em><asp:Label ID="labCustomer" runat="server" /></em>
      <br />
      <asp:CheckBox ID="chkValidCustomer" runat="server" Text="Is Valid?" />    
      
      <asp:ListBox ID="lboxProducts" runat="server" />
      <br />Retrieved Product via index: 
      <em><asp:Label ID="labProduct" runat="server" /></em>
      <br />
      <asp:CheckBox ID="chkValidProducer" runat="server" Text="Is Valid?" /> 
   </div>
    </form>
</body>
</html>

File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Collections.Generic;
using System.Collections.ObjectModel;

public class Product: AbstractEntity 
{
   private string _name;
   private double _price;
   public Product(string id, string name, double price) : base(id)
  {
      _name = name;
      _price = price;
  }
   public string Name
   {
      get { return _name; }
      set { _name = value; }
   }
   public double Price
   {
      get { return _price; }
      set { _price = value; }
   }
   public override string ToString()
   {
      return Id + "," + Name + "," + Price;
   }
   public override bool IsValid
   {
      get {
         if (Id.Length > 0 && Name.Length > 0)
            return true;
         else
            return false;
      }
   }
}
public class EntityCollection<T> : Collection<T> where T : AbstractEntity
{   
   public T FindById(string id)
   {
      foreach (T entity in this.Items)
      {
         if (entity.Id == id)
            return entity;
      }
      return null;
   }

   public bool IsValid()
   {
      bool valid = true;
      foreach (T entity in this.Items)
      {
         if (!entity.IsValid)
            valid = false;
      }
      return valid;
   }

}
public partial class TestGenericCollections : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
       Customer c1 = new Customer("1", "A", "H", "123-4567");
       Customer c2 = new Customer("2", "B", "G", "456-1267");
       Customer c3 = new Customer("3", "C", "F", "564-7823");
       Customer c4 = new Customer("4", "D", "E", "253-6383");
       EntityCollection<Customer> customers = new EntityCollection<Customer>();
       customers.Add(c1);
       customers.Add(c2);
       customers.Add(c3);
       customers.Add(c4);
       lboxCustomers.DataSource = customers;
       lboxCustomers.DataBind();
       labCustomer.Text = customers[2].Name;
       chkValidCustomer.Checked = customers.IsValid();
       Product p1 = new Product("1", "ProductOne", 24.00);
       Product p2 = new Product("2", "", 59.00);
       EntityCollection<Product> products = new EntityCollection<Product>();
       products.Add(p1);
       products.Add(p2);
       lboxProducts.DataSource = products;
       lboxProducts.DataBind();
       labProduct.Text = products[0].Name;
       chkValidProducer.Checked = products.IsValid();
    }
}
public abstract class AbstractEntity
{
   private string _id;
  public AbstractEntity(string id)
  {
      _id = id;
  }

   public string Id
   {
      get { return _id; }
      set { _id = value; }
   }

   public abstract bool IsValid
   {
      get;
   }
}
public class Customer: AbstractEntity 
{
   private string _firstName;
   private string _lastName;
   private string _phone;
   public Customer(string id, string firstName, string lastName, string phone): base(id)
   {
      _firstName = firstName;
      _lastName = lastName;
      _phone = phone;
   }

   public string FirstName
   {
      get { return _firstName; }
      set { _firstName = value; }
   }
   public string LastName
   {
      get { return _lastName; }
      set { _lastName = value; }
   }
   public string Phone
   {
      get { return _phone; }
      set { _phone = value; }
   }
   public string Name
   {
      get { return LastName + ", " + FirstName; }
   }
   public override bool IsValid
   {
      get
      {
         if (Id.Length > 0 && LastName.Length > 0)
            return true;
         else
            return false;
      }
   }
   public override string ToString()
   {
      return Id + "," + Name + "," + Phone; 
   }
}
Источник — «http://nfex.ru/index.php?title=ASP.NET_Tutorial/Collections/Generics&oldid=2764»