SortedList(Of TKey, TValue).IDictionary.Contains Method (Object)
Determines whether the IDictionary contains an element with the specified key.
Assembly: System (in System.dll)
Parameters
- key
-
Type:
System.Object
The key to locate in the IDictionary.
Return Value
Type: System.Booleantrue if the IDictionary contains an element with the key; otherwise, false.
Implements
IDictionary.Contains(Object)| Exception | Condition |
|---|---|
| ArgumentNullException | key is null. |
This method returns false if key is of a type that is not assignable to the key type TKey of the SortedList(Of TKey, TValue).
This method is an O(log n) operation, where n is Count.
The following code example shows how to use the IDictionary.Contains method of the System.Collections.IDictionary interface with a SortedList(Of TKey, TValue). The example demonstrates that the method returns false if a key of the wrong data type is supplied.
The code example is part of a larger example, including output, provided for the IDictionary.Add method.
Imports System Imports System.Collections Imports System.Collections.Generic Public Class Example Public Shared Sub Main() ' Create a new sorted list of strings, with string keys, ' and access it using the IDictionary interface. ' Dim openWith As IDictionary = _ New sortedList(Of String, String) ' Add some elements to the sorted list. There are no ' duplicate keys, but some of the values are duplicates. ' IDictionary.Add throws an exception if incorrect types ' are supplied for key or value. openWith.Add("txt", "notepad.exe") openWith.Add("bmp", "paint.exe") openWith.Add("dib", "paint.exe") openWith.Add("rtf", "wordpad.exe")
' Contains can be used to test keys before inserting ' them. If Not openWith.Contains("ht") Then openWith.Add("ht", "hypertrm.exe") Console.WriteLine("Value added for key = ""ht"": {0}", _ openWith("ht")) End If ' IDictionary.Contains returns False if the wrong data ' type is supplied. Console.WriteLine("openWith.Contains(29.7) returns {0}", _ openWith.Contains(29.7))
Available since 10
.NET Framework
Available since 2.0