ListBox.SelectedIndexCollection Class
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ListBox.SelectedIndexCollection Class

 

Represents the collection containing the indexes to the selected items in a ListBox.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

System.Object
  System.Windows.Forms.ListBox.SelectedIndexCollection

public class SelectedIndexCollection : IList, ICollection, IEnumerable

NameDescription
System_CAPS_pubmethodListBox.SelectedIndexCollection(ListBox)

Initializes a new instance of the ListBox.SelectedIndexCollection class.

NameDescription
System_CAPS_pubpropertyCount

Gets the number of items in the collection.

System_CAPS_pubpropertyIsReadOnly

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

System_CAPS_pubpropertyItem[Int32]

Gets the index value at the specified index within this collection.

NameDescription
System_CAPS_pubmethodAdd(Int32)

Adds the ListBox at the specified index location.

System_CAPS_pubmethodClear()

Removes all controls from the collection.

System_CAPS_pubmethodContains(Int32)

Determines whether the specified index is located within the collection.

System_CAPS_pubmethodCopyTo(Array, Int32)

Copies the entire collection into an existing array at a specified location within the 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 an enumerator to use to iterate through the selected indexes collection.

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(Int32)

Returns the index within the ListBox.SelectedIndexCollection of the specified index from the ListBox.ObjectCollection of the ListBox.

System_CAPS_protmethodMemberwiseClone()

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

System_CAPS_pubmethodRemove(Int32)

Removes the specified control from the collection.

System_CAPS_pubmethodToString()

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

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Add(Object)

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.Add.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Clear()

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.Clear.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Contains(Object)

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.Contains.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.IndexOf(Object)

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.IndexOf.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Insert(Int32, Object)

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.Insert.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.Remove(Object)

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.Remove.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIList.RemoveAt(Int32)

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.RemoveAt.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyICollection.IsSynchronized

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see ICollection.IsSynchronized.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyICollection.SyncRoot

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see ICollection.SyncRoot.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIList.IsFixedSize

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.IsFixedSize.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIList.Item[Int32]

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IList.Item.

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.)

The ListBox.SelectedIndexCollection class stores the indexes to the selected items in the ListBox. The indexes stored in the ListBox.SelectedIndexCollection are index positions within the ListBox.ObjectCollection class. The ListBox.ObjectCollection class stores all items displayed in the ListBox.

The following table is an example of how the ListBox.ObjectCollection stores the items of the ListBox as well as their selection states within an example ListBox.

Index

Item

Selection state within the ListBox

0

object1

Unselected

1

object2

Selected

2

object3

Unselected

3

object4

Selected

4

object5

Selected

Based on the ListBox.ObjectCollection example in the previous table, the following table demonstrates how the ListBox.SelectedIndexCollection would appear.

Index

Index of selected item in ObjectCollection

0

1

1

3

2

4

You can use the properties and methods of this class to perform a variety of tasks with the collection. The Contains method enables you to determine whether an index position from the ListBox.ObjectCollection class is a member of the selected indexes stored in the ListBox.SelectedIndexCollection. Once you know that the item is located within the collection, you can use the IndexOf method to determine where a specific index position within the ListBox.ObjectCollection for the ListBox is stored.

The following example demonstrates how to use the FindString method to search for all instances of the search text in the items of the ListBox. The example uses the version of the FindString method that enables you to specify a starting search index from which to do a continual search of all items in the ListBox. The example also demonstrates how to determine when the FindString method begins searching from the top of the list after it reaches the bottom of the list of items to prevent a recursive search. Once items are found in the ListBox, they are selected using the SetSelected method.

private void FindAllOfMyString(string searchString)
{
   // Set the SelectionMode property of the ListBox to select multiple items.
   listBox1.SelectionMode = SelectionMode.MultiExtended;

   // Set our intial index variable to -1.
   int x =-1;
   // If the search string is empty exit.
   if (searchString.Length != 0)
   {
      // Loop through and find each item that matches the search string.
      do
      {
         // Retrieve the item based on the previous index found. Starts with -1 which searches start.
         x = listBox1.FindString(searchString, x);
         // If no item is found that matches exit.
         if (x != -1)
         {
            // Since the FindString loops infinitely, determine if we found first item again and exit.
            if (listBox1.SelectedIndices.Count > 0)
            {
               if(x == listBox1.SelectedIndices[0])
                  return;
            }
            // Select the item in the ListBox once it is found.
            listBox1.SetSelected(x,true);
         }

      }while(x != -1);
   }
}

.NET Framework
Available since 1.1

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

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