Assembly: mscorlib (in mscorlib.dll)
<SerializableAttribute> _ <ComVisibleAttribute(True)> _ Public MustInherit Class CollectionBase Implements IList, ICollection, IEnumerable
Dim instance As CollectionBase
[SerializableAttribute] [ComVisibleAttribute(true)] public abstract class CollectionBase : IList, ICollection, IEnumerable
[SerializableAttribute] [ComVisibleAttribute(true)] public ref class CollectionBase abstract : IList, ICollection, IEnumerable
/** @attribute SerializableAttribute() */ /** @attribute ComVisibleAttribute(true) */ public abstract class CollectionBase implements IList, ICollection, IEnumerable
SerializableAttribute ComVisibleAttribute(true) public abstract class CollectionBase implements IList, ICollection, IEnumerable
Un'istanza CollectionBase è sempre modificabile. Vedere ReadOnlyCollectionBase per una versione in sola lettura della classe.
La capacità di una classe CollectionBase è il numero di elementi che tale classe CollectionBase può contenere. La capacità iniziale predefinita per una classe CollectionBase è 16. Quando vengono aggiunti elementi a una classe CollectionBase, la capacità viene automaticamente aumentata secondo le necessità, tramite riallocazione. È possibile diminuire la capacità impostando la proprietà Capacity in modo esplicito.
Note per gli implementatori: Questa classe di base è fornita per facilitare agli implementatori la creazione di un insieme personalizzato fortemente tipizzato. Si consiglia ai responsabili dell'implementazione di estendere la classe base anziché crearne una personalizzata.Nell'esempio di codice riportato di seguito viene implementata la classe CollectionBase e tale implementazione viene utilizzata per creare un insieme di oggetti Int16.
Imports System Imports System.Collections Public Class Int16Collection Inherits CollectionBase Default Public Property Item(index As Integer) As Int16 Get Return CType(List(index), Int16) End Get Set List(index) = value End Set End Property Public Function Add(value As Int16) As Integer Return List.Add(value) End Function 'Add Public Function IndexOf(value As Int16) As Integer Return List.IndexOf(value) End Function 'IndexOf Public Sub Insert(index As Integer, value As Int16) List.Insert(index, value) End Sub 'Insert Public Sub Remove(value As Int16) List.Remove(value) End Sub 'Remove Public Function Contains(value As Int16) As Boolean ' If value is not of type Int16, this will return false. Return List.Contains(value) End Function 'Contains Protected Overrides Sub OnInsert(index As Integer, value As Object) ' Insert additional code to be run only when inserting values. End Sub 'OnInsert Protected Overrides Sub OnRemove(index As Integer, value As Object) ' Insert additional code to be run only when removing values. End Sub 'OnRemove Protected Overrides Sub OnSet(index As Integer, oldValue As Object, newValue As Object) ' Insert additional code to be run only when setting values. End Sub 'OnSet Protected Overrides Sub OnValidate(value As Object) If Not GetType(System.Int16).IsAssignableFrom(value.GetType()) Then Throw New ArgumentException("value must be of type Int16.", "value") End If End Sub 'OnValidate End Class 'Int16Collection Public Class SamplesCollectionBase Public Shared Sub Main() ' Creates and initializes a new CollectionBase. Dim myI16 As New Int16Collection() ' Adds elements to the collection. myI16.Add( 1 ) myI16.Add( 2 ) myI16.Add( 3 ) myI16.Add( 5 ) myI16.Add( 7 ) ' Display the contents of the collection using For Each. This is the preferred method. Console.WriteLine("Contents of the collection (using For Each):") PrintValues1(myI16) ' Display the contents of the collection using the enumerator. Console.WriteLine("Contents of the collection (using enumerator):") PrintValues2(myI16) ' Display the contents of the collection using the Count property and the Item property. Console.WriteLine("Initial contents of the collection (using Count and Item):") PrintIndexAndValues(myI16) ' Searches the collection with Contains and IndexOf. Console.WriteLine("Contains 3: {0}", myI16.Contains(3)) Console.WriteLine("2 is at index {0}.", myI16.IndexOf(2)) Console.WriteLine() ' Inserts an element into the collection at index 3. myI16.Insert(3, 13) Console.WriteLine("Contents of the collection after inserting at index 3:") PrintIndexAndValues(myI16) ' Gets and sets an element using the index. myI16(4) = 123 Console.WriteLine("Contents of the collection after setting the element at index 4 to 123:") PrintIndexAndValues(myI16) ' Removes an element from the collection. myI16.Remove(2) ' Display the contents of the collection using the Count property and the Item property. Console.WriteLine("Contents of the collection after removing the element 2:") PrintIndexAndValues(myI16) End Sub 'Main ' Uses the Count property and the Item property. Public Shared Sub PrintIndexAndValues(myCol As Int16Collection) Dim i As Integer For i = 0 To myCol.Count - 1 Console.WriteLine(" [{0}]: {1}", i, myCol(i)) Next i Console.WriteLine() End Sub 'PrintIndexAndValues ' 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 PrintValues1(myCol As Int16Collection) Dim i16 As Int16 For Each i16 In myCol Console.WriteLine(" {0}", i16) Next i16 Console.WriteLine() End Sub 'PrintValues1 ' Uses the enumerator. ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection. Public Shared Sub PrintValues2(myCol As Int16Collection) Dim myEnumerator As System.Collections.IEnumerator = myCol.GetEnumerator() While myEnumerator.MoveNext() Console.WriteLine(" {0}", myEnumerator.Current) End While Console.WriteLine() End Sub 'PrintValues2 End Class 'SamplesCollectionBase 'This code produces the following output. ' 'Contents of the collection (using For Each): ' 1 ' 2 ' 3 ' 5 ' 7 ' 'Contents of the collection (using enumerator): ' 1 ' 2 ' 3 ' 5 ' 7 ' 'Initial contents of the collection (using Count and Item): ' [0]: 1 ' [1]: 2 ' [2]: 3 ' [3]: 5 ' [4]: 7 ' 'Contains 3: True '2 is at index 1. ' 'Contents of the collection after inserting at index 3: ' [0]: 1 ' [1]: 2 ' [2]: 3 ' [3]: 13 ' [4]: 5 ' [5]: 7 ' 'Contents of the collection after setting the element at index 4 to 123: ' [0]: 1 ' [1]: 2 ' [2]: 3 ' [3]: 13 ' [4]: 123 ' [5]: 7 ' 'Contents of the collection after removing the element 2: ' [0]: 1 ' [1]: 3 ' [2]: 13 ' [3]: 123 ' [4]: 7
using System; using System.Collections; public class Int16Collection : CollectionBase { public Int16 this[ int index ] { get { return( (Int16) List[index] ); } set { List[index] = value; } } public int Add( Int16 value ) { return( List.Add( value ) ); } public int IndexOf( Int16 value ) { return( List.IndexOf( value ) ); } public void Insert( int index, Int16 value ) { List.Insert( index, value ); } public void Remove( Int16 value ) { List.Remove( value ); } public bool Contains( Int16 value ) { // If value is not of type Int16, this will return false. return( List.Contains( value ) ); } protected override void OnInsert( int index, Object value ) { // Insert additional code to be run only when inserting values. } protected override void OnRemove( int index, Object value ) { // Insert additional code to be run only when removing values. } protected override void OnSet( int index, Object oldValue, Object newValue ) { // Insert additional code to be run only when setting values. } protected override void OnValidate( Object value ) { if ( value.GetType() != typeof(System.Int16) ) throw new ArgumentException( "value must be of type Int16.", "value" ); } } public class SamplesCollectionBase { public static void Main() { // Create and initialize a new CollectionBase. Int16Collection myI16 = new Int16Collection(); // Add elements to the collection. myI16.Add( (Int16) 1 ); myI16.Add( (Int16) 2 ); myI16.Add( (Int16) 3 ); myI16.Add( (Int16) 5 ); myI16.Add( (Int16) 7 ); // Display the contents of the collection using foreach. This is the preferred method. Console.WriteLine( "Contents of the collection (using foreach):" ); PrintValues1( myI16 ); // Display the contents of the collection using the enumerator. Console.WriteLine( "Contents of the collection (using enumerator):" ); PrintValues2( myI16 ); // Display the contents of the collection using the Count property and the Item property. Console.WriteLine( "Initial contents of the collection (using Count and Item):" ); PrintIndexAndValues( myI16 ); // Search the collection with Contains and IndexOf. Console.WriteLine( "Contains 3: {0}", myI16.Contains( 3 ) ); Console.WriteLine( "2 is at index {0}.", myI16.IndexOf( 2 ) ); Console.WriteLine(); // Insert an element into the collection at index 3. myI16.Insert( 3, (Int16) 13 ); Console.WriteLine( "Contents of the collection after inserting at index 3:" ); PrintIndexAndValues( myI16 ); // Get and set an element using the index. myI16[4] = 123; Console.WriteLine( "Contents of the collection after setting the element at index 4 to 123:" ); PrintIndexAndValues( myI16 ); // Remove an element from the collection. myI16.Remove( (Int16) 2 ); // Display the contents of the collection using the Count property and the Item property. Console.WriteLine( "Contents of the collection after removing the element 2:" ); PrintIndexAndValues( myI16 ); } // Uses the Count property and the Item property. public static void PrintIndexAndValues( Int16Collection myCol ) { for ( int i = 0; i < myCol.Count; i++ ) Console.WriteLine( " [{0}]: {1}", i, myCol[i] ); Console.WriteLine(); } // 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 PrintValues1( Int16Collection myCol ) { foreach ( Int16 i16 in myCol ) Console.WriteLine( " {0}", i16 ); Console.WriteLine(); } // Uses the enumerator. // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection. public static void PrintValues2( Int16Collection myCol ) { System.Collections.IEnumerator myEnumerator = myCol.GetEnumerator(); while ( myEnumerator.MoveNext() ) Console.WriteLine( " {0}", myEnumerator.Current ); Console.WriteLine(); } } /* This code produces the following output. Contents of the collection (using foreach): 1 2 3 5 7 Contents of the collection (using enumerator): 1 2 3 5 7 Initial contents of the collection (using Count and Item): [0]: 1 [1]: 2 [2]: 3 [3]: 5 [4]: 7 Contains 3: True 2 is at index 1. Contents of the collection after inserting at index 3: [0]: 1 [1]: 2 [2]: 3 [3]: 13 [4]: 5 [5]: 7 Contents of the collection after setting the element at index 4 to 123: [0]: 1 [1]: 2 [2]: 3 [3]: 13 [4]: 123 [5]: 7 Contents of the collection after removing the element 2: [0]: 1 [1]: 3 [2]: 13 [3]: 123 [4]: 7 */
#using <System.dll> using namespace System; using namespace System::Collections; public ref class Int16Collection: public CollectionBase { public: property Int16 Item [int] { Int16 get( int index ) { return ( (Int16)(List[ index ])); } void set( int index, Int16 value ) { List[ index ] = value; } } int Add( Int16 value ) { return (List->Add( value )); } int IndexOf( Int16 value ) { return (List->IndexOf( value )); } void Insert( int index, Int16 value ) { List->Insert( index, value ); } void Remove( Int16 value ) { List->Remove( value ); } bool Contains( Int16 value ) { // If value is not of type Int16, this will return false. return (List->Contains( value )); } protected: virtual void OnInsert( int /*index*/, Object^ /*value*/ ) override { // Insert additional code to be run only when inserting values. } virtual void OnRemove( int /*index*/, Object^ /*value*/ ) override { // Insert additional code to be run only when removing values. } virtual void OnSet( int /*index*/, Object^ /*oldValue*/, Object^ /*newValue*/ ) override { // Insert additional code to be run only when setting values. } virtual void OnValidate( Object^ value ) override { if ( value->GetType() != Type::GetType( "System.Int16" ) ) throw gcnew ArgumentException( "value must be of type Int16.","value" ); } }; void PrintIndexAndValues( Int16Collection^ myCol ); void PrintValues2( Int16Collection^ myCol ); int main() { // Create and initialize a new CollectionBase. Int16Collection^ myI16 = gcnew Int16Collection; // Add elements to the collection. myI16->Add( (Int16)1 ); myI16->Add( (Int16)2 ); myI16->Add( (Int16)3 ); myI16->Add( (Int16)5 ); myI16->Add( (Int16)7 ); // Display the contents of the collection using the enumerator. Console::WriteLine( "Contents of the collection (using enumerator):" ); PrintValues2( myI16 ); // Display the contents of the collection using the Count property and the Item property. Console::WriteLine( "Initial contents of the collection (using Count and Item):" ); PrintIndexAndValues( myI16 ); // Search the collection with Contains and IndexOf. Console::WriteLine( "Contains 3: {0}", myI16->Contains( 3 ) ); Console::WriteLine( "2 is at index {0}.", myI16->IndexOf( 2 ) ); Console::WriteLine(); // Insert an element into the collection at index 3. myI16->Insert( 3, (Int16)13 ); Console::WriteLine( "Contents of the collection after inserting at index 3:" ); PrintIndexAndValues( myI16 ); // Get and set an element using the index. myI16->Item[ 4 ] = 123; Console::WriteLine( "Contents of the collection after setting the element at index 4 to 123:" ); PrintIndexAndValues( myI16 ); // Remove an element from the collection. myI16->Remove( (Int16)2 ); // Display the contents of the collection using the Count property and the Item property. Console::WriteLine( "Contents of the collection after removing the element 2:" ); PrintIndexAndValues( myI16 ); } // Uses the Count property and the Item property. void PrintIndexAndValues( Int16Collection^ myCol ) { for ( int i = 0; i < myCol->Count; i++ ) Console::WriteLine( " [{0}]: {1}", i, myCol->Item[ i ] ); Console::WriteLine(); } // Uses the enumerator. void PrintValues2( Int16Collection^ myCol ) { System::Collections::IEnumerator^ myEnumerator = myCol->GetEnumerator(); while ( myEnumerator->MoveNext() ) Console::WriteLine( " {0}", myEnumerator->Current ); Console::WriteLine(); } /* This code produces the following output. Contents of the collection (using enumerator): 1 2 3 5 7 Initial contents of the collection (using Count and Item): [0]: 1 [1]: 2 [2]: 3 [3]: 5 [4]: 7 Contains 3: True 2 is at index 1. Contents of the collection after inserting at index 3: [0]: 1 [1]: 2 [2]: 3 [3]: 13 [4]: 5 [5]: 7 Contents of the collection after setting the element at index 4 to 123: [0]: 1 [1]: 2 [2]: 3 [3]: 13 [4]: 123 [5]: 7 Contents of the collection after removing the element 2: [0]: 1 [1]: 3 [2]: 13 [3]: 123 [4]: 7 */
import System.* ;
import System.Collections.*;
import System.Collections.CollectionBase.*;
public class Int16Collection extends CollectionBase
{
/** @property
*/
public short get_Value(int index)
{
short s = System.Convert.ToInt16(get_List().get_Item(index));
return(s) ;
} //get_Value
/** @property
*/
public void set_Value(int index,short value)
{
get_List().set_Item(index, (Int16)value);
} //set_Value
public int Add(short value)
{
return get_List().Add((Int16)value);
} //Add
public int IndexOf(short value)
{
return get_List().IndexOf((Int16)value);
} //IndexOf
public void Insert(int index, short value)
{
get_List().Insert(index, (Int16)value);
} //Insert
public void Remove(short value)
{
get_List().Remove((Int16)value);
} //Remove
public boolean Contains(short value)
{
// If value is not of type Int16, this will return false.
return get_List().Contains((Int16)value);
} //Contains
protected void OnInsert(int index, Object value)
{
// Insert additional code to be run only when inserting values.
} //OnInsert
protected void OnRemove(int index, Object value)
{
// Insert additional code to be run only when removing values.
} //OnRemove
protected void OnSet(int index, Object oldValue, Object newValue)
{
// Insert additional code to be run only when setting values.
} //OnSet
protected void OnValidate(Object value)
{
if ( value.GetType() != Type.GetType("System.Int16") ) {
throw new ArgumentException("value must be of type Int16.",
"value");
}
} //OnValidate
} //Int16Collection
public class SamplesCollectionBase
{
public static void main(String[] args)
{
// Create and initialize a new CollectionBase.
Int16Collection myI16 = new Int16Collection();
// Add elements to the collection.
myI16.Add((Int16)1);
myI16.Add((Int16)2);
myI16.Add((Int16)3);
myI16.Add((Int16)5);
myI16.Add((Int16)7);
// Display the contents of the collection using for.
Console.WriteLine("Contents of the collection (using for):");
PrintValues1(myI16);
// Display the contents of the collection using the enumerator.
Console.WriteLine("Contents of the collection (using enumerator):");
PrintValues2(myI16);
// Display the contents of the collection using the Count property and
// the Item property.
Console.WriteLine("Initial contents of the collection "
+ "(using Count and Item):");
PrintIndexAndValues(myI16);
// Search the collection with Contains and IndexOf.
Console.WriteLine("Contains 3: {0}",
(System.Boolean)myI16.Contains((Int16)3));
Console.WriteLine("2 is at index {0}.",
(Int16)myI16.IndexOf((Int16)2));
Console.WriteLine();
// Insert an element into the collection at index 3.
myI16.Insert(3, (Int16)13);
Console.WriteLine("Contents of the collection after inserting at"
+ " index 3:");
PrintIndexAndValues(myI16);
// Get and set an element using the index.
myI16 .set_Item( 4 ,(Int16)123 );
Console.WriteLine("Contents of the collection after setting the"
+ " element at index 4 to 123:");
PrintIndexAndValues(myI16);
// Remove an element from the collection.
myI16.Remove((Int16)2);
// Display the contents of the collection using the Count property and
// the Item property.
Console.WriteLine("Contents of the collection after removing the"
+ " element 2:");
PrintIndexAndValues(myI16);
} //main
// Uses the Count property and the Item property.
public static void PrintIndexAndValues(Int16Collection myCol)
{
for(int i = 0; i < myCol.get_Count(); i++) {
Console.WriteLine(" [{0}]: {1}", (Int32)i,
myCol.get_Item(i));
}
Console.WriteLine();
} //PrintIndexAndValues
// Uses the for statement which hides the complexity of the enumerator.
// NOTE: The for statement is the preferred way of enumerating the contents
// of a collection.
public static void PrintValues1(Int16Collection myCol)
{
for (int iCtr = 0; iCtr < myCol.get_Count(); iCtr++) {
Console.WriteLine(" {0}", myCol.get_Item(iCtr));
}
Console.WriteLine();
} //PrintValues1
// Uses the enumerator.
// NOTE: The for statement is the preferred way of enumerating the contents
// of a collection.
public static void PrintValues2(Int16Collection myCol)
{
System.Collections.IEnumerator myEnumerator = myCol.GetEnumerator();
while(myEnumerator.MoveNext()) {
Console.WriteLine(" {0}", myEnumerator.get_Current());
}
Console.WriteLine();
} //PrintValues2
} //SamplesCollectionBase
/*
Contents of the collection (using for):
1
2
3
5
7
Contents of the collection (using enumerator):
1
2
3
5
7
Initial contents of the collection (using Count and Item):
[0]: 1
[1]: 2
[2]: 3
[3]: 5
[4]: 7
Contains 3: True
2 is at index 1.
Contents of the collection after inserting at index 3:
[0]: 1
[1]: 2
[2]: 3
[3]: 13
[4]: 5
[5]: 7
Contents of the collection after setting the element at index 4 to 123:
[0]: 1
[1]: 2
[2]: 3
[3]: 13
[4]: 123
[5]: 7
Contents of the collection after removing the element 2:
[0]: 1
[1]: 3
[2]: 13
[3]: 123
[4]: 7
*/
System.Collections.CollectionBase
Classi derivate
I membri statici pubblici (Shared in Visual Basic) di questo tipo sono thread-safe. Qualsiasi membro di istanza non ha garanzia di essere thread-safe.
Questa implementazione non fornisce un wrapper sincronizzato (thread-safe) per una classe CollectionBase, ma le classi derivate possono creare direttamente una propria versione sincronizzata di CollectionBase utilizzando la proprietà SyncRoot.
L'enumerazione di un insieme non è di per sé una procedura thread-safe. Anche se un insieme è sincronizzato, è possibile che venga modificato da altri thread, con conseguente generazione di un'eccezione da parte dell'enumeratore. Per garantire che un insieme sia thread-safe durante l'enumerazione, è possibile bloccarlo nel corso dell'operazione oppure rilevare le eccezioni generate dalle modifiche apportate da altri thread.
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile per Pocket PC, Windows Mobile per Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework non supporta tutte le versioni di ciascuna piattaforma. Per un elenco delle versioni supportate, vedere Requisiti di sistema.