StringCollection Class

 

Represents a collection of strings.

Namespace:   System.Collections.Specialized
Assembly:  System (in System.dll)

System.Object
  System.Collections.Specialized.StringCollection
    System.Configuration.CommaDelimitedStringCollection

[SerializableAttribute]
public class StringCollection : IList, ICollection, IEnumerable

NameDescription
System_CAPS_pubmethodStringCollection()

Initializes a new instance of the StringCollection class.

NameDescription
System_CAPS_pubpropertyCount

Gets the number of strings contained in the StringCollection.

System_CAPS_pubpropertyIsReadOnly

Gets a value indicating whether the StringCollection is read-only.

System_CAPS_pubpropertyIsSynchronized

Gets a value indicating whether access to the StringCollection is synchronized (thread safe).

System_CAPS_pubpropertyItem[Int32]

Gets or sets the element at the specified index.

System_CAPS_pubpropertySyncRoot

Gets an object that can be used to synchronize access to the StringCollection.

NameDescription
System_CAPS_pubmethodAdd(String)

Adds a string to the end of the StringCollection.

System_CAPS_pubmethodAddRange(String[])

Copies the elements of a string array to the end of the StringCollection.

System_CAPS_pubmethodClear()

Removes all the strings from the StringCollection.

System_CAPS_pubmethodContains(String)

Determines whether the specified string is in the StringCollection.

System_CAPS_pubmethodCopyTo(String[], Int32)

Copies the entire StringCollection values to a one-dimensional array of strings, starting at the specified index of the target array.

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodGetEnumerator()

Returns a StringEnumerator that iterates through the StringCollection.

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodIndexOf(String)

Searches for the specified string and returns the zero-based index of the first occurrence within the StringCollection.

System_CAPS_pubmethodInsert(Int32, String)

Inserts a string into the StringCollection at the specified index.

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethodRemove(String)

Removes the first occurrence of a specific string from the StringCollection.

System_CAPS_pubmethodRemoveAt(Int32)

Removes the string at the specified index of the StringCollection.

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethodICollection.CopyTo(Array, Int32)

Copies the entire StringCollection to a compatible one-dimensional Array, starting at the specified index of the target array.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIEnumerable.GetEnumerator()

Returns a IEnumerator that iterates through the StringCollection.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Add(Object)

Adds an object to the end of the StringCollection.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Contains(Object)

Determines whether an element is in the StringCollection.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.IndexOf(Object)

Searches for the specified Object and returns the zero-based index of the first occurrence within the entire StringCollection.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Insert(Int32, Object)

Inserts an element into the StringCollection at the specified index.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Remove(Object)

Removes the first occurrence of a specific object from the StringCollection.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIList.IsFixedSize

Gets a value indicating whether the StringCollection object has a fixed size.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIList.IsReadOnly

Gets a value indicating whether the StringCollection object is read-only.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIList.Item[Int32]

Gets or sets the element at the specified index.

NameDescription
System_CAPS_pubmethodAsParallel()

Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.)

System_CAPS_pubmethodAsQueryable()

Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.)

System_CAPS_pubmethodCast<TResult>()

Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.)

System_CAPS_pubmethodOfType<TResult>()

Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.)

StringCollection accepts null as a valid value and allows duplicate elements.

String comparisons are case-sensitive.

Elements in this collection can be accessed using an integer index. Indexes in this collection are zero-based.

The following code example demonstrates several of the properties and methods of StringCollection.

using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesStringCollection  {

   public static void Main()  {

      // Create and initializes a new StringCollection.
      StringCollection myCol = new StringCollection();

      // Add a range of elements from an array to the end of the StringCollection.
      String[] myArr = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" };
      myCol.AddRange( myArr );

      // Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine( "Displays the elements using foreach:" );
      PrintValues1( myCol );

      // Display the contents of the collection using the enumerator.
      Console.WriteLine( "Displays the elements using the IEnumerator:" );
      PrintValues2( myCol );

      // Display the contents of the collection using the Count and Item properties.
      Console.WriteLine( "Displays the elements using the Count and Item properties:" );
      PrintValues3( myCol );

      // Add one element to the end of the StringCollection and insert another at index 3.
      myCol.Add( "* white" );
      myCol.Insert( 3, "* gray" );

      Console.WriteLine( "After adding \"* white\" to the end and inserting \"* gray\" at index 3:" );
      PrintValues1( myCol );

      // Remove one element from the StringCollection.
      myCol.Remove( "yellow" );

      Console.WriteLine( "After removing \"yellow\":" );
      PrintValues1( myCol );

      // Remove all occurrences of a value from the StringCollection.
      int i = myCol.IndexOf( "RED" );
      while ( i > -1 )  {
         myCol.RemoveAt( i );
         i = myCol.IndexOf( "RED" );
      }

      // Verify that all occurrences of "RED" are gone.
      if ( myCol.Contains( "RED" ) )
         Console.WriteLine( "*** The collection still contains \"RED\"." );

      Console.WriteLine( "After removing all occurrences of \"RED\":" );
      PrintValues1( myCol );

      // Copy the collection to a new array starting at index 0.
      String[] myArr2 = new String[myCol.Count];
      myCol.CopyTo( myArr2, 0 );

      Console.WriteLine( "The new array contains:" );
      for ( i = 0; i < myArr2.Length; i++ )  {
         Console.WriteLine( "   [{0}] {1}", i, myArr2[i] );
      }
      Console.WriteLine();

      // Clears the entire collection.
      myCol.Clear();

      Console.WriteLine( "After clearing the collection:" );
      PrintValues1( myCol );

   }

   // Uses the foreach statement which hides the complexity of the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintValues1( StringCollection myCol )  {
      foreach ( Object obj in myCol )
         Console.WriteLine( "   {0}", obj );
      Console.WriteLine();
   }

   // Uses the enumerator. 
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintValues2( StringCollection myCol )  {
      StringEnumerator myEnumerator = myCol.GetEnumerator();
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0}", myEnumerator.Current );
      Console.WriteLine();
   }

   // Uses the Count and Item properties.
   public static void PrintValues3( StringCollection myCol )  {
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0}", myCol[i] );
      Console.WriteLine();
   }

}

/*
This code produces the following output.

Displays the elements using foreach:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

Displays the elements using the IEnumerator:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

Displays the elements using the Count and Item properties:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

After adding "* white" to the end and inserting "* gray" at index 3:
   RED
   orange
   yellow
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing "yellow":
   RED
   orange
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing all occurrences of "RED":
   orange
   * gray
   green
   blue
   indigo
   violet
   * white

The new array contains:
   [0] orange
   [1] * gray
   [2] green
   [3] blue
   [4] indigo
   [5] violet
   [6] * white

After clearing the collection:

*/

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1

Public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

This implementation does not provide a synchronized (thread safe) wrapper for a StringCollection, but derived classes can create their own synchronized versions of the StringCollection using the SyncRoot property.

Enumerating through a collection is intrinsically not a thread safe procedure. Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

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