ASP.NET Tutorial/Collections/Hashtable
Содержание
- 1 Hashtable collection
- 2 Hashtable Example
- 2.1 Retrieving Person objects from a Hashtable (C#)
- 2.2 Retrieving Person objects from a Hashtable (VB)
- 2.3 Using For Each with a Hashtable"s default IEnumerator implementation (C#)
- 2.4 Using For Each with a Hashtable"s default IEnumerator implementation (VB)
- 2.5 Using For Each with a Hashtable"s Keys and Values member collections (C#)
- 2.6 Using For Each with a Hashtable"s Keys and Values member collections (VB)
Hashtable collection
<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="UsingHashtable" %> <!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>Hashtable Example</title>
</head> <body>
<form id="form1" runat="server">
Hashtable Example
<asp:ListBox ID="lboxCustomers" runat="server" DataTextField="Value" DataValueField="Key" />
</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 UsingHashtable : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e) { Customer c1 = new Customer("1", "A", "AA", "123-4567"); Customer c2 = new Customer("2", "B", "BB", "123-7823"); Customer c3 = new Customer("3", "C", "CC", "123-6383"); Hashtable table = new Hashtable(); table.Add(c1.Id, c1); table.Add(c2.Id, c2); table.Add(c3.Id, c3); lboxCustomers.DataSource = table; lboxCustomers.DataBind(); }
}</source>
Retrieving Person objects from a Hashtable (C#)
<source lang="csharp">
<%@ 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">
</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"); Hashtable peopleHashtable = new Hashtable(); peopleHashtable.Add("sh", scott); peopleHashtable.Add("be", bill); peopleHashtable.Add("ss", srini); Person found = (Person)peopleHashtable["sh"]; Response.Write(found.FullName + "
"); found = (Person)peopleHashtable["be"]; Response.Write(found.FullName + "
"); found = (Person)peopleHashtable["sh"]; Response.Write(found.FullName + "
"); }
} 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; } }
}</source>
Retrieving Person objects from a Hashtable (VB)
<source lang="csharp">
<%@ 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">
</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 peopleHashtable As New Hashtable() peopleHashtable.Add("sh", scott) peopleHashtable.Add("be", bill) peopleHashtable.Add("ss", srini) Dim found As Person = CType(peopleHashtable("sh"), Person) Response.Write(found.FullName & "
") found = CType(peopleHashtable("be"), Person) Response.Write(found.FullName & "
") found = CType(peopleHashtable("sh"), Person) Response.Write(found.FullName & "
") End Sub
End Class</source>
Using For Each with a Hashtable"s default IEnumerator implementation (C#)
<source lang="csharp">
<%@ 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">
</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"); Hashtable peopleHashtable = new Hashtable(); peopleHashtable.Add("sh", scott); peopleHashtable.Add("be", bill); peopleHashtable.Add("ss", srini); Person found = (Person)peopleHashtable["sh"]; Response.Write(found.FullName + "
"); found = (Person)peopleHashtable["be"]; Response.Write(found.FullName + "
"); found = (Person)peopleHashtable["sh"]; Response.Write(found.FullName + "
"); foreach (DictionaryEntry de in peopleHashtable) { Response.Write(de.Key.ToString() + ":" + ((Person)de.Value).FullName + "
"); } }
} 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; } }
}</source>
Using For Each with a Hashtable"s default IEnumerator implementation (VB)
<source lang="csharp">
<%@ 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">
</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 peopleHashtable As New Hashtable() peopleHashtable.Add("sh", scott) peopleHashtable.Add("be", bill) peopleHashtable.Add("ss", srini) Dim found As Person = CType(peopleHashtable("sh"), Person) Response.Write(found.FullName & "
") found = CType(peopleHashtable("be"), Person) Response.Write(found.FullName & "
") found = CType(peopleHashtable("sh"), Person) Response.Write(found.FullName & "
") For Each de As DictionaryEntry In peopleHashtable Response.Write(de.Key.ToString() & ":" & CType(de.Value, Person).FullName & _ "
") Next End Sub
End Class</source>
Using For Each with a Hashtable"s Keys and Values member collections (C#)
<source lang="csharp">
<%@ 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">
</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"); Hashtable peopleHashtable = new Hashtable(); peopleHashtable.Add("sh", scott); peopleHashtable.Add("be", bill); peopleHashtable.Add("ss", srini); Person found = (Person)peopleHashtable["sh"]; Response.Write(found.FullName + "
"); found = (Person)peopleHashtable["be"]; Response.Write(found.FullName + "
"); found = (Person)peopleHashtable["sh"]; Response.Write(found.FullName + "
"); foreach (string s in peopleHashtable.Keys) { Response.Write(s + "
"); } foreach (Person p in peopleHashtable.Values) { Response.Write(p.FullName + "
"); } }
} 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; } }
}</source>
Using For Each with a Hashtable"s Keys and Values member collections (VB)
<source lang="csharp">
<%@ 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">
</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 peopleHashtable As New Hashtable() peopleHashtable.Add("sh", scott) peopleHashtable.Add("be", bill) peopleHashtable.Add("ss", srini) Dim found As Person = CType(peopleHashtable("sh"), Person) Response.Write(found.FullName & "
") found = CType(peopleHashtable("be"), Person) Response.Write(found.FullName & "
") found = CType(peopleHashtable("sh"), Person) Response.Write(found.FullName & "
") For Each s As String In peopleHashtable.Keys Response.Write(s & "
") Next For Each p As Person In peopleHashtable.Values Response.Write(p.FullName & "
") Next End Sub
End Class</source>