SortedList<TKey,TValue>.IDictionary.Contains(Object) 方法
定義
判斷 IDictionary 是否包含具有指定之索引鍵的項目。Determines whether the IDictionary contains an element with the specified key.
virtual bool System.Collections.IDictionary.Contains(System::Object ^ key) = System::Collections::IDictionary::Contains;
bool IDictionary.Contains (object key);
abstract member System.Collections.IDictionary.Contains : obj -> bool
override this.System.Collections.IDictionary.Contains : obj -> bool
Function Contains (key As Object) As Boolean Implements IDictionary.Contains
參數
- key
- Object
要在 IDictionary 中尋找的索引鍵。The key to locate in the IDictionary.
傳回
如果 true
包含具有該索引鍵的項目,則為 IDictionary,否則為 false
。true
if the IDictionary contains an element with the key; otherwise, false
.
實作
例外狀況
key
為 null
。key
is null
.
範例
下列程式碼範例示範如何搭配使用 IDictionary.Contains 介面的方法 System.Collections.IDictionary SortedList<TKey,TValue> 。The following code example shows how to use the IDictionary.Contains method of the System.Collections.IDictionary interface with a SortedList<TKey,TValue>. 此範例示範 false
如果提供了錯誤資料類型的索引鍵,方法會傳回。The example demonstrates that the method returns false
if a key of the wrong data type is supplied.
程式碼範例是針對方法提供的較大範例(包括輸出)的一部分 IDictionary.Add 。The code example is part of a larger example, including output, provided for the IDictionary.Add method.
using System;
using System.Collections;
using System.Collections.Generic;
public class Example
{
public static void Main()
{
// Create a new sorted list of strings, with string keys,
// and access it using the IDictionary interface.
//
IDictionary openWith = new SortedList<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");
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 (!openWith.Contains("ht"))
{
openWith.Add("ht", "hypertrm.exe");
Console.WriteLine("Value added for key = \"ht\": {0}",
openWith["ht"]);
}
// IDictionary.Contains returns false if the wrong data
// type is supplied.
Console.WriteLine("openWith.Contains(29.7) returns {0}",
openWith.Contains(29.7));
' 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))
}
}
End Sub
End Class
備註
false
如果的型別 key
無法指派給的索引鍵類型,則這個方法會傳回 TKey
SortedList<TKey,TValue> 。This method returns false
if key
is of a type that is not assignable to the key type TKey
of the SortedList<TKey,TValue>.
此方法是 O (記錄 n
) 作業,其中 n
是 Count 。This method is an O(log n
) operation, where n
is Count.