StringDictionary.Clear Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Removes all entries from the StringDictionary.
public:
virtual void Clear();
public virtual void Clear ();
abstract member Clear : unit -> unit
override this.Clear : unit -> unit
Public Overridable Sub Clear ()
Exceptions
The StringDictionary is read-only.
Examples
The following code example demonstrates how to add and remove elements from a StringDictionary.
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintKeysAndValues( StringDictionary^ myCol )
{
Console::WriteLine( " KEY VALUE" );
IEnumerator^ enum0 = myCol->GetEnumerator();
while ( enum0->MoveNext() )
{
DictionaryEntry^ de = safe_cast<DictionaryEntry^>(enum0->Current);
Console::WriteLine( " {0,-10} {1}", de->Key, de->Value );
}
Console::WriteLine();
}
int main()
{
// Creates and initializes a new StringDictionary.
StringDictionary^ myCol = gcnew StringDictionary;
myCol->Add( "red", "rojo" );
myCol->Add( "green", "verde" );
myCol->Add( "blue", "azul" );
// Displays the values in the StringDictionary.
Console::WriteLine( "Initial contents of the StringDictionary:" );
PrintKeysAndValues( myCol );
// Deletes an element.
myCol->Remove( "green" );
Console::WriteLine( "The collection contains the following elements after removing \"green\":" );
PrintKeysAndValues( myCol );
// Clears the entire collection.
myCol->Clear();
Console::WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues( myCol );
}
/*
This code produces the following output.
Initial contents of the StringDictionary:
KEY VALUE
green verde
red rojo
blue azul
The collection contains the following elements after removing "green":
KEY VALUE
red rojo
blue azul
The collection contains the following elements after it is cleared:
KEY VALUE
*/
using System;
using System.Collections;
using System.Collections.Specialized;
public class SamplesStringDictionary {
public static void Main() {
// Creates and initializes a new StringDictionary.
StringDictionary myCol = new StringDictionary();
myCol.Add( "red", "rojo" );
myCol.Add( "green", "verde" );
myCol.Add( "blue", "azul" );
// Displays the values in the StringDictionary.
Console.WriteLine( "Initial contents of the StringDictionary:" );
PrintKeysAndValues( myCol );
// Deletes an element.
myCol.Remove( "green" );
Console.WriteLine( "The collection contains the following elements after removing \"green\":" );
PrintKeysAndValues( myCol );
// Clears the entire collection.
myCol.Clear();
Console.WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues( myCol );
}
public static void PrintKeysAndValues( StringDictionary myCol ) {
Console.WriteLine( " KEY VALUE" );
foreach ( DictionaryEntry de in myCol )
Console.WriteLine( " {0,-10} {1}", de.Key, de.Value );
Console.WriteLine();
}
}
/*
This code produces the following output.
Initial contents of the StringDictionary:
KEY VALUE
green verde
red rojo
blue azul
The collection contains the following elements after removing "green":
KEY VALUE
red rojo
blue azul
The collection contains the following elements after it is cleared:
KEY VALUE
*/
Imports System.Collections
Imports System.Collections.Specialized
Public Class SamplesStringDictionary
Public Shared Sub Main()
' Creates and initializes a new StringDictionary.
Dim myCol As New StringDictionary()
myCol.Add("red", "rojo")
myCol.Add("green", "verde")
myCol.Add("blue", "azul")
' Displays the values in the StringDictionary.
Console.WriteLine("Initial contents of the StringDictionary:")
PrintKeysAndValues(myCol)
' Deletes an element.
myCol.Remove("green")
Console.WriteLine("The collection contains the following elements after removing ""green"":")
PrintKeysAndValues(myCol)
' Clears the entire collection.
myCol.Clear()
Console.WriteLine("The collection contains the following elements after it is cleared:")
PrintKeysAndValues(myCol)
End Sub
Public Shared Sub PrintKeysAndValues(myCol As StringDictionary)
Dim de As DictionaryEntry
Console.WriteLine(" KEY VALUE")
For Each de In myCol
Console.WriteLine(" {0,-10} {1}", de.Key, de.Value)
Next de
Console.WriteLine()
End Sub
End Class
'This code produces the following output.
'
'Initial contents of the StringDictionary:
' KEY VALUE
' green verde
' red rojo
' blue azul
'
'The collection contains the following elements after removing "green":
' KEY VALUE
' red rojo
' blue azul
'
'The collection contains the following elements after it is cleared:
' KEY VALUE
'
Remarks
This method is an O(n
) operation, where n
is Count.
Applies to
Bekerjasama dengan kami di GitHub
Sumber untuk kandungan ini boleh didapati di GitHub, di mana anda juga boleh mencipta dan menyemak isu dan menarik permintaan. Untuk maklumat lanjut, lihat panduan penyumbang kami.
Maklum balas
https://aka.ms/ContentUserFeedback.
Akan datang: Sepanjang 2024, kami akan menghentikan secara berperingkat Isu GitHub sebagai kaedah maklum balas untuk kandungan dan menggantikannya dengan sistem maklum balas baharu. Untuk mendapatkan maklumat lanjut lihat:Kirim dan lihat maklum balas untuk