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ReadOnlyCollectionBase::Count Property
Visual Studio 2008
Gets the number of elements contained in the ReadOnlyCollectionBase instance.
Assembly: mscorlib (in mscorlib.dll)
Property Value
Type: System::Int32The number of elements contained in the ReadOnlyCollectionBase instance.
Retrieving the value of this property is an O(1) operation.
Implements
ICollection::CountThe following code example implements the ReadOnlyCollectionBase class.
using namespace System; using namespace System::Collections; public ref class ROCollection: public ReadOnlyCollectionBase { public: ROCollection( IList^ sourceList ) { InnerList->AddRange( sourceList ); } property Object^ Item [int] { Object^ get( int index ) { return (InnerList[ index ]); } } int IndexOf( Object^ value ) { return (InnerList->IndexOf( value )); } bool Contains( Object^ value ) { return (InnerList->Contains( value )); } }; void PrintIndexAndValues( ROCollection^ myCol ); void PrintValues2( ROCollection^ myCol ); int main() { // Create an ArrayList. ArrayList^ myAL = gcnew ArrayList; myAL->Add( "red" ); myAL->Add( "blue" ); myAL->Add( "yellow" ); myAL->Add( "green" ); myAL->Add( "orange" ); myAL->Add( "purple" ); // Create a new ROCollection that contains the elements in myAL. ROCollection^ myCol = gcnew ROCollection( myAL ); // Display the contents of the collection using the enumerator. Console::WriteLine( "Contents of the collection (using enumerator):" ); PrintValues2( myCol ); // Display the contents of the collection using the Count property and the Item property. Console::WriteLine( "Contents of the collection (using Count and Item):" ); PrintIndexAndValues( myCol ); // Search the collection with Contains and IndexOf. Console::WriteLine( "Contains yellow: {0}", myCol->Contains( "yellow" ) ); Console::WriteLine( "orange is at index {0}.", myCol->IndexOf( "orange" ) ); Console::WriteLine(); } // Uses the Count property and the Item property. void PrintIndexAndValues( ROCollection^ myCol ) { for ( int i = 0; i < myCol->Count; i++ ) Console::WriteLine( " [{0}]: {1}", i, myCol->Item[ i ] ); Console::WriteLine(); } // Uses the enumerator. void PrintValues2( ROCollection^ 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): red blue yellow green orange purple Contents of the collection (using Count and Item): [0]: red [1]: blue [2]: yellow [3]: green [4]: orange [5]: purple Contains yellow: True orange is at index 4. */
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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