ListDictionary 建構函式

來源:

ListDictionary.cs

來源:

ListDictionary.cs

來源:

ListDictionary.cs

來源:

ListDictionary.cs

來源:

ListDictionary.cs

public:
 ListDictionary();

public ListDictionary();

Public Sub New ()

範例

以下程式碼範例展示了 的 ListDictionary多項性質與方法 。

using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesListDictionary  {

   public static void Main()  {

      // Creates and initializes a new ListDictionary.
      ListDictionary myCol = new ListDictionary();
      myCol.Add( "Braeburn Apples", "1.49" );
      myCol.Add( "Fuji Apples", "1.29" );
      myCol.Add( "Gala Apples", "1.49" );
      myCol.Add( "Golden Delicious Apples", "1.29" );
      myCol.Add( "Granny Smith Apples", "0.89" );
      myCol.Add( "Red Delicious Apples", "0.99" );

      // Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine( "Displays the elements using foreach:" );
      PrintKeysAndValues1( myCol );

      // Display the contents of the collection using the enumerator.
      Console.WriteLine( "Displays the elements using the IDictionaryEnumerator:" );
      PrintKeysAndValues2( myCol );

      // Display the contents of the collection using the Keys, Values, Count, and Item properties.
      Console.WriteLine( "Displays the elements using the Keys, Values, Count, and Item properties:" );
      PrintKeysAndValues3( myCol );

      // Copies the ListDictionary to an array with DictionaryEntry elements.
      DictionaryEntry[] myArr = new DictionaryEntry[myCol.Count];
      myCol.CopyTo( myArr, 0 );

      // Displays the values in the array.
      Console.WriteLine( "Displays the elements in the array:" );
      Console.WriteLine( "   KEY                       VALUE" );
      for ( int i = 0; i < myArr.Length; i++ )
         Console.WriteLine( "   {0,-25} {1}", myArr[i].Key, myArr[i].Value );
      Console.WriteLine();

      // Searches for a key.
      if ( myCol.Contains( "Kiwis" ) )
         Console.WriteLine( "The collection contains the key \"Kiwis\"." );
      else
         Console.WriteLine( "The collection does not contain the key \"Kiwis\"." );
      Console.WriteLine();

      // Deletes a key.
      myCol.Remove( "Plums" );
      Console.WriteLine( "The collection contains the following elements after removing \"Plums\":" );
      PrintKeysAndValues1( myCol );

      // Clears the entire collection.
      myCol.Clear();
      Console.WriteLine( "The collection contains the following elements after it is cleared:" );
      PrintKeysAndValues1( myCol );
   }

   // Uses the foreach statement which hides the complexity of the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues1( IDictionary myCol )  {
      Console.WriteLine( "   KEY                       VALUE" );
      foreach ( DictionaryEntry de in myCol )
         Console.WriteLine( "   {0,-25} {1}", de.Key, de.Value );
      Console.WriteLine();
   }

   // Uses the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues2( IDictionary myCol )  {
      IDictionaryEnumerator myEnumerator = myCol.GetEnumerator();
      Console.WriteLine( "   KEY                       VALUE" );
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value );
      Console.WriteLine();
   }

   // Uses the Keys, Values, Count, and Item properties.
   public static void PrintKeysAndValues3( ListDictionary myCol )  {
      String[] myKeys = new String[myCol.Count];
      myCol.Keys.CopyTo( myKeys, 0 );

      Console.WriteLine( "   INDEX KEY                       VALUE" );
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0,-5} {1,-25} {2}", i, myKeys[i], myCol[myKeys[i]] );
      Console.WriteLine();
   }
}

/*
This code produces output similar to the following.
Note that because a dictionary is implemented for fast keyed access the order
of the items in the dictionary are not gauranteed and, as a result, should not
be depended on.

Displays the elements using foreach:
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

Displays the elements using the IDictionaryEnumerator:
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

Displays the elements using the Keys, Values, Count, and Item properties:
   INDEX KEY                       VALUE
   0     Braeburn Apples           1.49
   1     Fuji Apples               1.29
   2     Gala Apples               1.49
   3     Golden Delicious Apples   1.29
   4     Granny Smith Apples       0.89
   5     Red Delicious Apples      0.99

Displays the elements in the array:
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

The collection does not contain the key "Kiwis".

The collection contains the following elements after removing "Plums":
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

The collection contains the following elements after it is cleared:
   KEY                       VALUE


*/

Imports System.Collections
Imports System.Collections.Specialized

Public Class SamplesListDictionary   

   Public Shared Sub Main()

      ' Creates and initializes a new ListDictionary.
      Dim myCol As New ListDictionary()
      myCol.Add("Braeburn Apples", "1.49")
      myCol.Add("Fuji Apples", "1.29")
      myCol.Add("Gala Apples", "1.49")
      myCol.Add("Golden Delicious Apples", "1.29")
      myCol.Add("Granny Smith Apples", "0.89")
      myCol.Add("Red Delicious Apples", "0.99")

      ' Display the contents of the collection using For Each. This is the preferred method.
      Console.WriteLine("Displays the elements using For Each:")
      PrintKeysAndValues(myCol)

      ' Display the contents of the collection using the enumerator.
      Console.WriteLine("Displays the elements using the IDictionaryEnumerator:")
      PrintKeysAndValues2(myCol)

      ' Display the contents of the collection using the Keys, Values, Count, and Item properties.
      Console.WriteLine("Displays the elements using the Keys, Values, Count, and Item properties:")
      PrintKeysAndValues3(myCol)

      ' Copies the ListDictionary to an array with DictionaryEntry elements.
      Dim myArr(myCol.Count) As DictionaryEntry
      myCol.CopyTo(myArr, 0)

      ' Displays the values in the array.
      Console.WriteLine("Displays the elements in the array:")
      Console.WriteLine("   KEY                       VALUE")
      Dim i As Integer
      For i = 0 To myArr.Length - 1
         Console.WriteLine("   {0,-25} {1}", myArr(i).Key, myArr(i).Value)
      Next i
      Console.WriteLine()

      ' Searches for a key.
      If myCol.Contains("Kiwis") Then
         Console.WriteLine("The collection contains the key ""Kiwis"".")
      Else
         Console.WriteLine("The collection does not contain the key ""Kiwis"".")
      End If
      Console.WriteLine()

      ' Deletes a key.
      myCol.Remove("Plums")
      Console.WriteLine("The collection contains the following elements after removing ""Plums"":")
      PrintKeysAndValues(myCol)

      ' Clears the entire collection.
      myCol.Clear()
      Console.WriteLine("The collection contains the following elements after it is cleared:")
      PrintKeysAndValues(myCol)

   End Sub


   ' Uses the For Each statement which hides the complexity of the enumerator.
   ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintKeysAndValues(myCol As IDictionary)

      Console.WriteLine("   KEY                       VALUE")
      Dim de As DictionaryEntry
      For Each de In  myCol
         Console.WriteLine("   {0,-25} {1}", de.Key, de.Value)
      Next de
      Console.WriteLine()

   End Sub


   ' Uses the enumerator. 
   ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintKeysAndValues2(myCol As IDictionary)
      Dim myEnumerator As IDictionaryEnumerator = myCol.GetEnumerator()

      Console.WriteLine("   KEY                       VALUE")
      While myEnumerator.MoveNext()
         Console.WriteLine("   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value)
      End While
      Console.WriteLine()

   End Sub


   ' Uses the Keys, Values, Count, and Item properties.
   Public Shared Sub PrintKeysAndValues3(myCol As ListDictionary)
      Dim myKeys(myCol.Count) As [String]
      myCol.Keys.CopyTo(myKeys, 0)

      Console.WriteLine("   INDEX KEY                       VALUE")
      Dim i As Integer
      For i = 0 To myCol.Count - 1
         Console.WriteLine("   {0,-5} {1,-25} {2}", i, myKeys(i), myCol(myKeys(i)))
      Next i
      Console.WriteLine()

   End Sub

End Class


'This code produces the following output.
'Note that because a dictionary is implemented for fast keyed access the order
'of the items in the dictionary are not gauranteed and, as a result, should not
'be depended on.
'
'Displays the elements using for each:
'   KEY                       VALUE
'   Braeburn Apples           1.49
'   Fuji Apples               1.29
'   Gala Apples               1.49
'   Golden Delicious Apples   1.29
'   Granny Smith Apples       0.89
'   Red Delicious Apples      0.99
'
'Displays the elements using the IDictionaryEnumerator:
'   KEY                       VALUE
'   Braeburn Apples           1.49
'   Fuji Apples               1.29
'   Gala Apples               1.49
'   Golden Delicious Apples   1.29
'   Granny Smith Apples       0.89
'   Red Delicious Apples      0.99
'
'Displays the elements using the Keys, Values, Count, and Item properties:
'   INDEX KEY                       VALUE
'   0     Braeburn Apples           1.49
'   1     Fuji Apples               1.29
'   2     Gala Apples               1.49
'   3     Golden Delicious Apples   1.29
'   4     Granny Smith Apples       0.89
'   5     Red Delicious Apples      0.99
'
'Displays the elements in the array:
'   KEY                       VALUE
'   Braeburn Apples           1.49
'   Fuji Apples               1.29
'   Gala Apples               1.49
'   Golden Delicious Apples   1.29
'   Granny Smith Apples       0.89
'   Red Delicious Apples      0.99
'
'The collection does not contain the key "Kiwis".
'
'The collection contains the following elements after removing "Plums":
'   KEY                       VALUE
'   Braeburn Apples           1.49
'   Fuji Apples               1.29
'   Gala Apples               1.49
'   Golden Delicious Apples   1.29
'   Granny Smith Apples       0.89
'   Red Delicious Apples      0.99
'
'The collection contains the following elements after it is cleared:
'   KEY                       VALUE
'

備註

比較器判斷兩個鍵是否相等。 ListDictionary 中的每個鍵必須是唯一的。 預設比較器是該鍵對 Object.Equals的實作。

此構造子為 O（1） 運算。

另請參閱

• 執行 Culture-Insensitive 字串操作

來源:

ListDictionary.cs

來源:

ListDictionary.cs

來源:

ListDictionary.cs

來源:

ListDictionary.cs

來源:

ListDictionary.cs

public:
 ListDictionary(System::Collections::IComparer ^ comparer);

public ListDictionary(System.Collections.IComparer comparer);

public ListDictionary(System.Collections.IComparer? comparer);

new System.Collections.Specialized.ListDictionary : System.Collections.IComparer -> System.Collections.Specialized.ListDictionary

Public Sub New (comparer As IComparer)

參數

備註

比較器判斷兩個鍵是否相等。 ListDictionary 中的每個鍵必須是唯一的。 預設比較器是該鍵對 Object.Equals的實作。

自訂比較器能實現使用大小寫不區分字串的查詢等情境。

此構造子為 O（1） 運算。

另請參閱

• IComparer
• Equals(Object)
• 執行 Culture-Insensitive 字串操作