Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All

StringDictionary.Clear Method

Removes all entries from the StringDictionary.

[Visual Basic]
Public Overridable Sub Clear()
[C#]
public virtual void Clear();
[C++]
public: virtual void Clear();
[JScript]
public function Clear();

Exceptions

Exception Type Condition
NotSupportedException The StringDictionary is read-only.

Example

[Visual Basic, C#, C++] The following code example demonstrates how to add and remove elements from a StringDictionary.

[Visual Basic] 
Imports System
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 'Main

   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 'PrintKeysAndValues

End Class 'SamplesStringDictionary 


'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
'


[C#] 
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

*/

[C++] 
#using <mscorlib.dll>
#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;

void PrintKeysAndValues( StringDictionary* myCol )  {
   Console::WriteLine( S"   KEY        VALUE" );
   IEnumerator* enum0 = myCol->GetEnumerator();
   while (enum0->MoveNext())
   {
      DictionaryEntry* de = __try_cast<DictionaryEntry*>(enum0->Current);
      Console::WriteLine( S"   {0,-10} {1}", de->Key, de->Value );
   }
   Console::WriteLine();
}

int main()  {

   // Creates and initializes a new StringDictionary.
   StringDictionary* myCol = new StringDictionary();
   myCol->Add( S"red", S"rojo" );
   myCol->Add( S"green", S"verde" );
   myCol->Add( S"blue", S"azul" );

   // Displays the values in the StringDictionary.
   Console::WriteLine( S"Initial contents of the StringDictionary:" );
   PrintKeysAndValues( myCol );

   // Deletes an element.
   myCol->Remove( S"green" );
   Console::WriteLine( S"The collection contains the following elements after removing \"green\":" );
   PrintKeysAndValues( myCol );

   // Clears the entire collection.
   myCol->Clear();
   Console::WriteLine( S"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

*/

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

StringDictionary Class | StringDictionary Members | System.Collections.Specialized Namespace

Show:
© 2015 Microsoft