????? ????? ?? ?????? HashTable ?? Visual Basic .NET ?? ?? Visual Basic 2005

?????? ????????? ?????? ?????????
???? ???????: 307933 - ??? ???????? ???? ????? ????? ??? ???????.
????? ???? | ?? ????

?? ??? ??????

??????

???? ??? ??????? ??????? ??? ?????? HashTable. ??? ??????? ???? ?????? ????? ??????? ???????? ???????? ????????, ????? ??????? ??????? ???????? ???????? ???? ????. ????? ?????? ???? ??????? ???? ?????? ???? ????????.

???? "?????? ??? ?????" ??? HashTable ?? ????? ?? ????? ????? System.Collections ???? ?? ??? ???????? ??? ??????? ???????.

??????? ??????? ?????? ?? ?????

?????? HashTable ?????? ??? (????? ? ??????) ??????? ????? ??????? ??????? ??? ???? ???????. ????? immutable ??? ?? ???? ???? ??????? ????? ?? HashTable. ?????? ??? ??????? ??? ?????? ????? ????? ????? ?????? ?? HashTable. ??? ??????? ??? ??????? ??? ??? ?????.
  1. ???? Microsoft Visual Studio .NET ?? Microsoft Visual Studio 2005 ?? ????? ????? ????? Windows ?? Visual Basic .NET ?? ?? Visual Basic 2005. ??? ????? Form1 ??? ??????? ???? ???????.
  2. ?? "?????? ??????" ???? ??? ?????? ?????? ??? ??? ??????? ? ??? ??? ????? ? ?? ???? ??? ????? ??? ?????? ??? ???? ?????. ??? ????? Class1 ??? ??????? ???? ???????.
  3. ?? ???? ?????? ????? ???? ???? ? ???? ??? ???.

    ?????? ?? Visual Studio 2005 ? ???? ??? ????? ????? ?? ???.
  4. ?????? ??? ??????? ?????? ?? ?????? ??????? Class1 ???????? ???????? ???????:
    Public Class Person
        Public Fname, Lname As String
    
        Sub New(ByVal FirstName As String, ByVal LastName As String)
            Fname = FirstName
            Lname = LastName
        End Sub
    
        Public Overrides Function ToString() As String
            Return Fname + " " + Lname
        End Function
    End Class
    						
    ????? ??? ??????? ????? ???? ???? ???? ???????? ????? ????? "?" ??? ??????? ????? ?????? ??? ???????? ??? ????????? ???????. ?????? ?????? ToStringToString ?? ??? ???? ?????? FnameLname ?????? ????.
  5. ?? Form1.vb ? ??? ????? ?????? ????????? ??????? ??? ???? ?????? ??????? ????????? ????????:
    Imports System.Collections
    					
  6. ?? ?????? ???? ???? Hashtable ????? ??????? ?? ??????? ????? ????????? ?? ????? ?????. ?? ?????? ????????? ???????? ??????? ??? ??? Form1:
    Dim MyTable As New Hashtable()
    
    'For simplicity, create three Person objects to add to the HashTable collection.
    
    Dim Person1, Person2, Person3 As Person  
    					
  7. ?? ??????? ??????? ??????? ??????? Add???? ???? Hashtable ????? ????? ?????? ????? ??? Hashtable ?? ???? ???????? catch. ???? ???????? catch catches ????????? ???? ????? ?? ???? ???? ?????? ?????.
    1. ??? ???? ???? ?? ??? Form1 ?????? ??????? Text ??? ????? ?????.
    2. ???? ????? ??????? ??? ???? ??? ???? ????????? ???????? ?????? ?? ?? ?? ???? ???????? ???????? ??????? ?? ????? Button1_Click:
      Person1 = New Person("Karen", "Berge")
      Person2 = New Person("David", "Campbell")
      Person3 = New Person("Jim", "Kim")
      
      'The Add method takes Key as the first parameter and Value as the second parameter.
      
      Try
           MyTable.Add(Person1.Lname, Person1)
           MyTable.Add(Person2.Lname, Person2)
           MyTable.Add(Person3.Lname, Person3)
      Catch ae As ArgumentException
           MessageBox.Show("Duplicate Key")
      End Try
      						
  8. ???? ???? Hashtable ???? ?????. ?? ??????? ???????? ???? ??????? ?????? ??? ?????? ??????? ?? ?????? ???????.
    1. ????? ???? ???? ?? ??? Form1 ?????? ??????? Text ??? ????? ???????.
    2. ???? ????? ??????? ??? ???? ?? ?? ???? ???????? ???????? ??????? ?? ????? Button2_Click:
      'Use the indexer of the Hashtable class to retrieve your objects. The indexer takes 
      'Key as a parameter and accesses it with the Hashed location.
              
      Try
           MessageBox.Show(MyTable(Person1.Lname).ToString)
           MessageBox.Show(MyTable(Person2.Lname).ToString)
           MessageBox.Show(MyTable(Person3.Lname).ToString)
      Catch ex As NullReferenceException
           MessageBox.Show("Key not in Hashtable")
      End Try
      						
  9. ?? ??????? ???????? ?????? ??????? ????? ?????? ???? ???? ?? ?????? HashTable:
    1. ????? ???? ???? ?? ??? Form1 ?????? ??????? Text ??? ????? ??????.
    2. ???? ????? ??????? ??? ???? ?? ?? ???? ???????? ???????? ??????? ?? ????? Button3_Click:
      'Use the Count property.
      If (MyTable.Count = 0) Then
           MessageBox.Show("There are no items in HashTable")
      Else
           MessageBox.Show("The count before removing an Item is" & " " & MyTable.Count)
           MessageBox.Show("Removing value stored at key value (Berge)")
           'Remove the object that is stored at the Key value Person1.Lname.
           MyTable.Remove(Person1.Lname)
      End If
      						
  10. ?? ??????? ??????? ????? ??????? ???? ??? ??????? ?? ?????? HashTable.
    1. ????? ???? ???? ?? ??? Form1 ?????? ??????? Text ??? ???????.
    2. ???? ????? ??????? ??? ???? ?? ?? ???? ???????? ???????? ??????? ?? ????? Button4_Click:
      Dim Enumerator As IDictionaryEnumerator
      Enumerator = MyTable.GetEnumerator()
      
      If (MyTable.Count = 0) Then
           MessageBox.Show("The HashTable is empty")
      Else
           MessageBox.Show("Enumerating through the HashTable collection")
           While Enumerator.MoveNext()
                MessageBox.Show(Enumerator.Value.ToString())
           End While
      End If
      
      Dim MyKeys As ICollection
      Dim Key As Object
      
      If (MyTable.Count = 0) Then
           MessageBox.Show("The HashTable is empty")
      Else
           MessageBox.Show("Accessing keys property to return keys collection")
           MyKeys = MyTable.Keys()
      
           For Each Key In MyKeys
                MessageBox.Show(Key.ToString)
           Next
      End If 
      							
      ????????? ???????? ??? ??????? ?? ?????? ??? IDictionaryEnumerator ??? ???????? ??????? GetEnumerator ???????? HashTable. ?? ???? ????? ? ???????? ???????? ????? ???? ??????? ???????? ?? ???????? ??????? ????? ??????HashTable ????? ???? ????????.
  11. ?? ??????? ???????? ?????? ??????? ??? ???? HashTable.
    1. ????? ???? ???? ?? ??? Form1 ?????? ??????? Text ??? ???.
    2. ???? ????? ??????? ??? ???? ?? ?? ???? ???????? ???????? ??????? ?? ????? Button5_Click:
      MyTable.Clear()
      MessageBox.Show("HashTable is now empty")
      						
  12. ???? ??????? ??????? ?????? ??????? ???????:
    1. ???? ??? ????? ???????. ???? ?? ??? ????? ????? ?????? ????? ??? ???????? HashTable.
    2. ???? ??? ?????? ??? ???????. ???? ?? ??????? ???? ??? ??????? ???????? ?? ?????? HashTable. ????? ??????? ?????? ??? ??? ???????.
    3. ???? ??? ????? ??????. ???? ??? ??? ??? ?????? ?? ?????? "????" ???????.
    4. ???? ??? ?????. ???? ????? IDictionaryEnumerator ???? ??????? ???????? ?? ?????? HashTable.
    5. ???? ??? ???. ???? ?? ??? ??? ???? ??????? ?? ?????? HashTable.
??????: ??????? ? ???????? ? ?????? ? ????? ?????? ? ?????? ?????? ?????????? ? ???????? ? ???????, ? ???????? ?????? ????? ??? ?????? ?????. ?? ????? ?? ???? ? ??????? ? ??????, ??? ?????? ? ????? ?????? ?????????? ? ???? ? ????? ?? ????? ?? ????? ?? ??? ??? ??????? ??? ?????? ?? ??? ?????.

???????

???? ???????: 307933 - ????? ??? ??????: 15/?? ??????/1427 - ??????: 3.3
????? ???
  • Microsoft Visual Basic 2005
  • Microsoft Visual Basic .NET 2003 Standard Edition
  • Microsoft Visual Basic .NET 2002 Standard Edition
????? ??????: 
kbmt kbvs2005swept kbvs2005applies kbhowtomaster KB307933 KbMtar
????? ????
???: ??? ????? ??? ?????? ???????? ?????? ????? ???? ????? ?????????? ????? ?? ????????? ?????? ????. ???? ???? ?????????? ???? ?? ???????? ???????? ?????? ????????? ????? ????????? ???????? ????? ???????? ?????? ?? ?????? ??? ?? ???????? ???????? ?? ????? ??????? ?????? ??? ??????? ?????? ??. ?????? ?? ???? ??? ??????? ???????? ????? ?? ???? ????? ?????? ??? ????? ??? ????? ??????? ?? ????? ?? ?????? ??? ??? ??????? ??????? ?? ????? ????? ????? ????? ?????. ?? ????? ???? ?????????? ??????? ??? ????? ?? ??????? ?? ????? ?????? ?? ??? ????? ?? ????? ??????? ?? ???????? ?? ??? ???????. ???? ???? ?????????? ???????? ??? ????? ?????? ??????? ??????
???? ??? ????? ??????? ?????? ??????????307933

????? ???????

 

Contact us for more help

Contact us for more help
Connect with Answer Desk for expert help.
Get more support from smallbusiness.support.microsoft.com