ASP.NET Tutorial/Collections/ArrayList

Содержание

1 Add objects to ArrayList (C#)
2 Add objects to ArrayList (VB)
3 ArrayList with custom objects
4 Bind ArrayList to DropDownList
5 Foreach loop (C#)
6 Foreach loop (VB)
7 Using a custom strongly typed PersonList (C#)
8 Using a custom strongly typed PersonList (VB)
9 Using an ArrayList instead of an array (C#)
10 Using an ArrayList instead of an array (VB)

Add objects to ArrayList (C#)

<%@ Page Language="C#" %>
<script runat="server">
private void Page_Load(object sender, System.EventArgs e)
{
  System.Collections.ArrayList al = new System.Collections.ArrayList(5);
  
  al.Add("one");
  al.Add(2);
  al.Add(false);
  al.Add(new System.Object());
  
  Response.Write("Successfully added " + al.Count + " different types of objects to an ArrayList.");
}
</script>

Add objects to ArrayList (VB)

<%@ Page Language="VB" %>
<script runat="server">
Sub Page_Load (Sender As Object, E As EventArgs)
  Dim al As New ArrayList(5)
  
  al.Add("one")
  al.Add(2)
  al.Add(False)
  al.Add(New System.Object())
  
  Response.Write("Successfully added " & al.Count & " different types of objects to an ArrayList.")
End Sub
</script>

ArrayList with custom objects

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="UsingArrayList" %>
<!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>Using an ArrayList</title>
</head>
<body>
   <form id="form1" runat="server">
      <div id="container">
         <h1>Using an ArrayList</h1>
         
         In this example, the drop-down list is 
         data bound to an <code>ArrayList</code>.
         
         
         <asp:Panel ID="panList" runat="server" >
         <h2>Select customer from list:</h2>
         
         <asp:ListBox id="lboxCustomers" runat="server" AutoPostBack="True"
            DataTextField="Name"
           DataValueField="Id"  
           OnSelectedIndexChanged="SelectCustomer" />
        
         </asp:Panel>
         
      <asp:Panel ID="panCustomer" runat="server" CssClass="panelBox">          
        <h2>Customer Information</h2>
         Id:<br />
        <asp:TextBox id="txtId" runat="server" />
         First Name:<br />
        <asp:TextBox id="txtFirst" runat="server" />
         Last Name:<br />
        <asp:TextBox id="txtLast" runat="server" />
         Phone Number:<br />
        <asp:TextBox id="txtPhone" runat="server" />
      </asp:Panel>
      </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;
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 
{
   // data members
   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; 
   }
}
public partial class UsingArrayList : System.Web.UI.Page
{
   private ArrayList _customers;
   private void Page_Load(object sender, System.EventArgs e)
   {
      _customers = new ArrayList();
      FillCustomers();
      if (!IsPostBack)
      {
         lboxCustomers.DataSource = _customers;
         lboxCustomers.DataBind();
         panCustomer.Visible = false;
      }
   }
   private void FillCustomers()
   {
      Customer c1 = new Customer("1", "A", "AA", "123-4567");
      Customer c2 = new Customer("2", "B", "BB", "456-1267");
      Customer c3 = new Customer("3", "C", "CC", "564-7823");
      Customer c4 = new Customer("4", "D", "DD", "253-6383");
      _customers.Add(c1);
      _customers.Add(c2);
      _customers.Add(c3);
      _customers.Add(c4);
   }

    protected void SelectCustomer(object sender, System.EventArgs e)
    {
       int index = lboxCustomers.SelectedIndex;
    
       if (index >= 0 && index <= _customers.Count)
       {
          Customer c = (Customer)_customers[index];
    
          txtId.Text = c.Id;
          txtFirst.Text = c.FirstName;
          txtLast.Text = c.LastName;
          txtPhone.Text = c.Phone;
    
          panCustomer.Visible = true;
       }
    }
}

Bind ArrayList to DropDownList

<script language="C#" runat="server">
protected void Page_Load(object o, EventArgs e) {
    if(!IsPostBack) {
        ArrayList arrayList = new ArrayList();
        arrayList.Add("C#");
        arrayList.Add("VB.NET");
        arrayList.Add("JScript.Net");
        languageDropDownList.DataSource = arrayList;
        languageDropDownList.DataBind();
        favoriteLanguage.Text = languageDropDownList.SelectedItem.Value;
    }
}
protected void DropDownListSelectionChanged(object o, EventArgs e) {
    favoriteLanguage.Text = languageDropDownList.SelectedItem.Text;
}
</script>
<form runat="server">
<asp:DropDownList 
    id="languageDropDownList"
    runat="server" 
    OnSelectedIndexChanged="DropDownListSelectionChanged" >
</asp:DropDownList><br/>
Favorite Language: <b><asp:Label runat="server" id="favoriteLanguage" style="color:blue" /></b><br />
<asp:Button runat="server" Text="Submit"/>
</form>

Foreach loop (C#)

<%@ Page %>
<script language="C#" runat="server">
  private void Page_Load(object sender, System.EventArgs e)
  {
    int i;
    System.Collections.ArrayList myList=new System.Collections.ArrayList();
    myList.Add("Zero");
    myList.Add("One");
    myList.Add("Two");
    myList.Add("Three");
    myList.Add("Four");
    myList.Add("Five");
    foreach (string number in myList)
    {
      Response.Write(number.ToString() + "<BR>");
    }
  }
</script>
<html>
  <body>
    <form id="form1" method="post" runat="server">
    </form>
  </body>
</html>

Foreach loop (VB)

<%@ Page %>
<script language="vb" runat="server">
  Sub Page_Load(sender As Object, e As EventArgs)
    Dim i As Integer
    Dim item As String
    Dim myList As New System.Collections.ArrayList()
    myList.Add("Zero")
    myList.Add("One")
    myList.Add("Two")
    myList.Add("Three")
    myList.Add("Four")
    myList.Add("Five")
    For Each item In myList
      Response.Write(Item & "<BR>")
    Next
  End Sub
</script>
<html>
  <body>
    <form id="form1" method="post" runat="server">
    </form>
  </body>
</html>

Using a custom strongly typed PersonList (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;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Person scott = new Person("A", "B");
        Person bill = new Person("C", "D");
        Person srini = new Person("E", "F");
        PersonList people = new PersonList();
        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 PersonList : System.Collections.IEnumerable
{
    private ArrayList innerList = new ArrayList();
    public void Add(Person aPerson)
    {
        innerList.Add(aPerson);
    }
    public void Remove(Person aPerson)
    {
        innerList.Remove(aPerson);
    }
    public int Count
    {
        get { return innerList.Count; }
    }
    // Get/set element at given index
    public Person this[int index]
    {
        get { return (Person)innerList[index]; }
        set { innerList[index] = value; }
    }
    public IEnumerator GetEnumerator()
    {
        return innerList.GetEnumerator();
    }
}

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;
        }
    }
}

Using a custom strongly typed PersonList (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 Microsoft.VisualBasic
Imports System.Collections
Public Class PersonList
    Implements System.Collections.IEnumerable
    Private innerList As ArrayList = New ArrayList()
    Public Sub Add(ByVal aPerson As Person)
        innerList.Add(aPerson)
    End Sub
    Public Sub Remove(ByVal aPerson As Person)
        innerList.Remove(aPerson)
    End Sub
    Public ReadOnly Property Count() As Integer
        Get
            Return innerList.Count
        End Get
    End Property
    "Get/set element at given index
    Default Public Property Item(ByVal index As Integer) As Person
        Get
            Return CType(innerList(index), Person)
        End Get
        Set(ByVal Value As Person)
            innerList(index) = Value
        End Set
    End Property
    Public Function GetEnumerator() As IEnumerator _
            Implements IEnumerable.GetEnumerator
        Return innerList.GetEnumerator()
    End Function
End Class
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", "B")
        Dim bill As New Person("C", "D")
        Dim srini As New Person("E", "F")
        Dim people As New PersonList()
        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

Using an ArrayList instead of an array (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;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Person scott = new Person("A", "B");
        Person bill = new Person("C", "D");
        Person srini = new Person("E", "F");
        ArrayList people = new ArrayList();
        people.Add(scott);
        people.Add(bill);
        people.Add(srini);
        Response.Write("We used foreach.<BR/>");
        foreach (Person p in people)
        {
            Response.Write(p.FullName + "<BR/>");
        }
        Response.Write("Sort...<BR/>");
        people.Sort();
        Response.Write("We used foreach.<BR/>");
        foreach (Person p in people)
        {
            Response.Write(p.FullName + "<BR/>");
        }
        Person scott2 = new Person("A", "B");
        int indexOfA2 = people.IndexOf(scott2);
        Response.Write("A #2 is at " + indexOfA2 + "<BR/>");
        int indexOfEquivalentA = people.BinarySearch(scott2);
        Response.Write("An Equivalent A is at " + indexOfEquivalentA +
        "<BR/>");
        Response.Write("We used a for loop.<BR/>");
        for (int i = 0; i < people.Count; i++)
        {
            Response.Write(((Person)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;
        }
    }
}

Using an ArrayList instead of an array (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 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", "B")
        Dim bill As New Person("C", "D")
        Dim srini As New Person("E", "F")
        Dim people As New ArrayList()
        people.Add(scott)
        people.Add(bill)
        people.Add(srini)
        Response.Write("Unsorted. We used foreach.<BR/>")
        For Each p As Person In people
            Response.Write(p.FullName & "<BR/>")
        Next
        Response.Write("Sort...<BR/>")
        people.Sort()
        Response.Write("Sorted. We used foreach.<BR/>")
        For Each p As Person In people
            Response.Write(p.FullName & "<BR/>")
        Next
        Dim scott2 As New Person("A", "B")
        Dim indexOfA2 As Integer = people.IndexOf(scott2)
        Response.Write("A #2 is at " & indexOfA2 & "<BR/>")
        Dim indexOfEquivalentA As Integer = people.BinarySearch(scott2)
        Response.Write("An Equivalent A is at " & _
            indexOfEquivalentA & "<BR/>")
        Response.Write("We used a for loop.<BR/>")
        For i As Integer = 0 To people.Count - 1
            Response.Write(CType(people(i), Person).FullName & "<BR/>")
        Next
    End Sub
End Class

ASP.NET Tutorial/Collections/ArrayList

Содержание

Add objects to ArrayList (C#)

Add objects to ArrayList (VB)

ArrayList with custom objects

Bind ArrayList to DropDownList

Foreach loop (C#)

Foreach loop (VB)

Using a custom strongly typed PersonList (C#)

Using a custom strongly typed PersonList (VB)

Using an ArrayList instead of an array (C#)

Using an ArrayList instead of an array (VB)

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