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

Boolean

如果 true 包含具有該索引鍵的項目,則為 IDictionary,否則為 falsetrue if the IDictionary contains an element with the key; otherwise, false.

實作

例外狀況

keynullkey 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.AddThe 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 nCountThis method is an O(log n) operation, where n is Count.

適用於

另請參閱