HybridDictionary::Contains Method (Object^)
Determines whether the HybridDictionary contains a specific key.
Assembly: System (in System.dll)
Parameters
- key
-
Type:
System::Object^
The key to locate in the HybridDictionary.
Return Value
Type: System::Booleantrue if the HybridDictionary contains an entry with the specified key; otherwise, false.
Implements
IDictionary::Contains(Object^)| Exception | Condition |
|---|---|
| ArgumentNullException | key is null. |
This method is an O(1) operation.
Starting with the .NET Framework 2.0, this method uses the collection’s objects’ Equals and CompareTo methods on key to determine whether item exists. In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.
The following code example searches for an element in a HybridDictionary.
#using <System.dll> using namespace System; using namespace System::Collections; using namespace System::Collections::Specialized; void PrintKeysAndValues( IDictionary^ myCol ) { Console::WriteLine( " KEY VALUE" ); IEnumerator^ myEnum = myCol->GetEnumerator(); while ( myEnum->MoveNext() ) { DictionaryEntry de = safe_cast<DictionaryEntry>(myEnum->Current); Console::WriteLine( " {0,-25} {1}", de.Key, de.Value ); } Console::WriteLine(); } int main() { // Creates and initializes a new HybridDictionary. HybridDictionary^ myCol = gcnew HybridDictionary; 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" ); myCol->Add( "Plantain Bananas", "1.49" ); myCol->Add( "Yellow Bananas", "0.79" ); myCol->Add( "Strawberries", "3.33" ); myCol->Add( "Cranberries", "5.98" ); myCol->Add( "Navel Oranges", "1.29" ); myCol->Add( "Grapes", "1.99" ); myCol->Add( "Honeydew Melon", "0.59" ); myCol->Add( "Seedless Watermelon", "0.49" ); myCol->Add( "Pineapple", "1.49" ); myCol->Add( "Nectarine", "1.99" ); myCol->Add( "Plums", "1.69" ); myCol->Add( "Peaches", "1.99" ); // Displays the values in the HybridDictionary in three different ways. Console::WriteLine( "Initial contents of the HybridDictionary:" ); PrintKeysAndValues( myCol ); // 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(); } /* This code produces the following output. Initial contents of the HybridDictionary: KEY VALUE Seedless Watermelon 0.49 Nectarine 1.99 Cranberries 5.98 Plantain Bananas 1.49 Honeydew Melon 0.59 Pineapple 1.49 Strawberries 3.33 Grapes 1.99 Braeburn Apples 1.49 Peaches 1.99 Red Delicious Apples 0.99 Golden Delicious Apples 1.29 Yellow Bananas 0.79 Granny Smith Apples 0.89 Gala Apples 1.49 Plums 1.69 Navel Oranges 1.29 Fuji Apples 1.29 The collection does not contain the key "Kiwis". */
Available since 10
.NET Framework
Available since 1.1