NameObjectCollectionBase.BaseClear Method
.NET Framework 4.5
Removes all entries from the NameObjectCollectionBase instance.
Namespace: System.Collections.Specialized
Assembly: System (in System.dll)
| Exception | Condition |
|---|---|
| NotSupportedException | The collection is read-only. |
Count is set to zero, and references to other objects from elements of the collection are also released.
This method is an O(1) operation.
The following code example uses BaseClear to remove all elements from a NameObjectCollectionBase.
using System; using System.Collections; using System.Collections.Specialized; public class MyCollection : NameObjectCollectionBase { private DictionaryEntry _de = new DictionaryEntry(); // Gets a key-and-value pair (DictionaryEntry) using an index. public DictionaryEntry this[ int index ] { get { _de.Key = this.BaseGetKey( index ); _de.Value = this.BaseGet( index ); return( _de ); } } // Adds elements from an IDictionary into the new collection. public MyCollection( IDictionary d ) { foreach ( DictionaryEntry de in d ) { this.BaseAdd( (String) de.Key, de.Value ); } } // Clears all the elements in the collection. public void Clear() { this.BaseClear(); } } public class SamplesNameObjectCollectionBase { public static void Main() { // Creates and initializes a new MyCollection instance. IDictionary d = new ListDictionary(); d.Add( "red", "apple" ); d.Add( "yellow", "banana" ); d.Add( "green", "pear" ); MyCollection myCol = new MyCollection( d ); Console.WriteLine( "Initial state of the collection (Count = {0}):", myCol.Count ); PrintKeysAndValues( myCol ); // Removes all elements from the collection. myCol.Clear(); Console.WriteLine( "After clearing the collection (Count = {0}):", myCol.Count ); PrintKeysAndValues( myCol ); } public static void PrintKeysAndValues( MyCollection myCol ) { for ( int i = 0; i < myCol.Count; i++ ) { Console.WriteLine( "[{0}] : {1}, {2}", i, myCol[i].Key, myCol[i].Value ); } } } /* This code produces the following output. Initial state of the collection (Count = 3): [0] : red, apple [1] : yellow, banana [2] : green, pear After clearing the collection (Count = 0): */
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.