SortedList<TKey,TValue>.IDictionary.Add(Object, Object) Methode
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Fügt der IDictionary-Schnittstelle ein Element mit dem angegebenen Schlüssel und Wert hinzu.
virtual void System.Collections.IDictionary.Add(System::Object ^ key, System::Object ^ value) = System::Collections::IDictionary::Add;void IDictionary.Add (object key, object value);abstract member System.Collections.IDictionary.Add : obj * obj -> unit
override this.System.Collections.IDictionary.Add : obj * obj -> unitSub Add (key As Object, value As Object) Implements IDictionary.AddParameter
Implementiert
Ausnahmen
key ist null.
key weist einen Typ auf, der dem Schlüsseltyp TKey des IDictionary nicht zugeordnet werden kann.
- oder -
value weist einen Typ auf, der dem Werttyp TValue des IDictionary nicht zugeordnet werden kann.
- oder -
In IDictionary ist bereits ein Element mit demselben Schlüssel enthalten.
Beispiele
Im folgenden Codebeispiel wird gezeigt, wie Sie über die -Schnittstelle auf die SortedList<TKey,TValue>System.Collections.IDictionary -Klasse zugreifen. Im Codebeispiel wird eine leere SortedList<TKey,TValue> Zeichenfolge mit Zeichenfolgenschlüsseln erstellt und die IDictionary.Add -Methode verwendet, um einige Elemente hinzuzufügen. Das Beispiel zeigt, dass die IDictionary.Add -Methode eine ArgumentException auslöst, wenn versucht wird, einen doppelten Schlüssel hinzuzufügen, oder wenn ein Schlüssel oder Wert des falschen Datentyps angegeben wird.
Das Codebeispiel veranschaulicht die Verwendung mehrerer anderer Member der System.Collections.IDictionary Schnittstelle.
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");
try
{
openWith.Add(42, new Example());
}
catch (ArgumentException ex)
{
Console.WriteLine("An exception was caught for " +
"IDictionary.Add. Exception message:\n\t{0}\n",
ex.Message);
}
// The Add method throws an exception if the new key is
// already in the sorted list.
try
{
openWith.Add("txt", "winword.exe");
}
catch (ArgumentException)
{
Console.WriteLine("An element with Key = \"txt\" already exists.");
}
// The Item property is another name for the indexer, so you
// can omit its name when accessing elements.
Console.WriteLine("For key = \"rtf\", value = {0}.",
openWith["rtf"]);
// The indexer can be used to change the value associated
// with a key.
openWith["rtf"] = "winword.exe";
Console.WriteLine("For key = \"rtf\", value = {0}.",
openWith["rtf"]);
// If a key does not exist, setting the indexer for that key
// adds a new key/value pair.
openWith["doc"] = "winword.exe";
// The indexer returns null if the key is of the wrong data
// type.
Console.WriteLine("The indexer returns null"
+ " if the key is of the wrong type:");
Console.WriteLine("For key = 2, value = {0}.",
openWith[2]);
// The indexer throws an exception when setting a value
// if the key is of the wrong data type.
try
{
openWith[2] = "This does not get added.";
}
catch (ArgumentException)
{
Console.WriteLine("A key of the wrong type was specified"
+ " when assigning to the indexer.");
}
// Unlike the default Item property on the SorteList class
// itself, IDictionary.Item does not throw an exception
// if the requested key is not in the sorted list.
Console.WriteLine("For key = \"tif\", value = {0}.",
openWith["tif"]);
// 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));
// When you use foreach to enumerate sorted list elements
// with the IDictionary interface, the elements are retrieved
// as DictionaryEntry objects instead of KeyValuePair objects.
Console.WriteLine();
foreach( DictionaryEntry de in openWith )
{
Console.WriteLine("Key = {0}, Value = {1}",
de.Key, de.Value);
}
// To get the values alone, use the Values property.
ICollection icoll = openWith.Values;
// The elements of the collection are strongly typed
// with the type that was specified for values,
// even though the ICollection interface is not strongly
// typed.
Console.WriteLine();
foreach( string s in icoll )
{
Console.WriteLine("Value = {0}", s);
}
// To get the keys alone, use the Keys property.
icoll = openWith.Keys;
// The elements of the collection are strongly typed
// with the type that was specified for keys,
// even though the ICollection interface is not strongly
// typed.
Console.WriteLine();
foreach( string s in icoll )
{
Console.WriteLine("Key = {0}", s);
}
// Use the Remove method to remove a key/value pair. No
// exception is thrown if the wrong data type is supplied.
Console.WriteLine("\nRemove(\"dib\")");
openWith.Remove("dib");
if (!openWith.Contains("dib"))
{
Console.WriteLine("Key \"dib\" is not found.");
}
}
}
/* This code example produces the following output:
An exception was caught for IDictionary.Add. Exception message:
The value "42" is not of type "System.String" and cannot be used in this generic collection.
Parameter name: key
An element with Key = "txt" already exists.
For key = "rtf", value = wordpad.exe.
For key = "rtf", value = winword.exe.
The indexer returns null if the key is of the wrong type:
For key = 2, value = .
A key of the wrong type was specified when assigning to the indexer.
For key = "tif", value = .
Value added for key = "ht": hypertrm.exe
openWith.Contains(29.7) returns False
Key = txt, Value = notepad.exe
Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = rtf, Value = winword.exe
Key = doc, Value = winword.exe
Key = ht, Value = hypertrm.exe
Value = notepad.exe
Value = paint.exe
Value = paint.exe
Value = winword.exe
Value = winword.exe
Value = hypertrm.exe
Key = txt
Key = bmp
Key = dib
Key = rtf
Key = doc
Key = ht
Remove("dib")
Key "dib" is not found.
*/
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")
Try
openWith.Add(42, New Example())
Catch ex As ArgumentException
Console.WriteLine("An exception was caught for " & _
"IDictionary.Add. Exception message:" & vbLf _
& vbTab & ex.Message & vbLf)
End Try
' The Add method throws an exception if the new key is
' already in the sorted list.
Try
openWith.Add("txt", "winword.exe")
Catch
Console.WriteLine("An element with Key = ""txt"" already exists.")
End Try
' The Item property is the default property, so you
' can omit its name when accessing elements.
Console.WriteLine("For key = ""rtf"", value = {0}.", _
openWith("rtf"))
' The default Item property can be used to change the value
' associated with a key.
openWith("rtf") = "winword.exe"
Console.WriteLine("For key = ""rtf"", value = {0}.", _
openWith("rtf"))
' If a key does not exist, setting the default Item property
' for that key adds a new key/value pair.
openWith("doc") = "winword.exe"
' The default Item property returns Nothing if the key
' is of the wrong data type.
Console.WriteLine("The default Item property returns Nothing" _
& " if the key is of the wrong type:")
Console.WriteLine("For key = 2, value = {0}.", _
openWith(2))
' The default Item property throws an exception when setting
' a value if the key is of the wrong data type.
Try
openWith(2) = "This does not get added."
Catch
Console.WriteLine("A key of the wrong type was specified" _
& " when setting the default Item property.")
End Try
' Unlike the default Item property on the SortedList class
' itself, IDictionary.Item does not throw an exception
' if the requested key is not in the sorted list.
Console.WriteLine("For key = ""tif"", value = {0}.", _
openWith("tif"))
' 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))
' When you use foreach to enumerate sorted list elements
' with the IDictionary interface, the elements are retrieved
' as DictionaryEntry objects instead of KeyValuePair objects.
Console.WriteLine()
For Each de As DictionaryEntry In openWith
Console.WriteLine("Key = {0}, Value = {1}", _
de.Key, de.Value)
Next
' To get the values alone, use the Values property.
Dim icoll As ICollection = openWith.Values
' The elements of the collection are strongly typed
' with the type that was specified for sorted list values,
' even though the ICollection interface is not strongly
' typed.
Console.WriteLine()
For Each s As String In icoll
Console.WriteLine("Value = {0}", s)
Next s
' To get the keys alone, use the Keys property.
icoll = openWith.Keys
' The elements of the collection are strongly typed
' with the type that was specified for sorted list keys,
' even though the ICollection interface is not strongly
' typed.
Console.WriteLine()
For Each s As String In icoll
Console.WriteLine("Key = {0}", s)
Next s
' Use the Remove method to remove a key/value pair. No
' exception is thrown if the wrong data type is supplied.
Console.WriteLine(vbLf + "Remove(""dib"")")
openWith.Remove("dib")
If Not openWith.Contains("dib") Then
Console.WriteLine("Key ""dib"" is not found.")
End If
End Sub
End Class
' This code example produces the following output:
'
'An exception was caught for IDictionary.Add. Exception message:
' The value "42" is not of type "System.String" and cannot be used in this generic collection.
'Parameter name: key
'
'An element with Key = "txt" already exists.
'For key = "rtf", value = wordpad.exe.
'For key = "rtf", value = winword.exe.
'The default Item property returns Nothing if the key is of the wrong type:
'For key = 2, value = .
'A key of the wrong type was specified when setting the default Item property.
'For key = "tif", value = .
'Value added for key = "ht": hypertrm.exe
'openWith.Contains(29.7) returns False
'
'Key = txt, Value = notepad.exe
'Key = bmp, Value = paint.exe
'Key = dib, Value = paint.exe
'Key = rtf, Value = winword.exe
'Key = doc, Value = winword.exe
'Key = ht, Value = hypertrm.exe
'
'Value = notepad.exe
'Value = paint.exe
'Value = paint.exe
'Value = winword.exe
'Value = winword.exe
'Value = hypertrm.exe
'
'Key = txt
'Key = bmp
'Key = dib
'Key = rtf
'Key = doc
'Key = ht
'
'Remove("dib")
'Key "dib" is not found.
'
Hinweise
Sie können auch die Item[] Eigenschaft zum Hinzufügen neuer Elemente durch Festlegen der Wert eines Schlüssels, der nicht vorhanden ist, im Wörterbuch enthalten z. B. myCollection["myNonexistentKey"] = myValue Wenn der angegebene Schlüssel jedoch bereits im Wörterbuch vorhanden ist, überschreibt das Festlegen der Item[] Eigenschaft den alten Wert. Im Gegensatz dazu ändert die Add -Methode keine vorhandenen Elemente.
Diese Methode ist ein O(n)-Vorgang für unsortierte Daten, wobei n ist Count. Es handelt sich um einen O(log n)-Vorgang, wenn das neue Element am Ende der Liste hinzugefügt wird. Wenn das Einfügen eine Größenänderung verursacht, lautet der Vorgang O(n).
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