CheckedListBox.CheckedIndexCollection Class
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CheckedListBox.CheckedIndexCollection Class

 

Encapsulates the collection of indexes of checked items (including items in an indeterminate state) in a CheckedListBox.

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

System.Object
  System.Windows.Forms.CheckedListBox.CheckedIndexCollection

public class CheckedIndexCollection : IList, ICollection, IEnumerable

NameDescription
System_CAPS_pubpropertyCount

Gets the number of checked items.

System_CAPS_pubpropertyIsReadOnly

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

System_CAPS_pubpropertyItem[Int32]

Gets the index of a checked item in the CheckedListBox control.

NameDescription
System_CAPS_pubmethodContains(Int32)

Determines whether the specified index is located in 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 that can be used to iterate through the CheckedIndices 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 an index into the collection of checked indexes.

System_CAPS_protmethodMemberwiseClone()

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

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. Adds an item to the CheckedListBox.CheckedIndexCollection. 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. Removes all items from the CheckedListBox.CheckedIndexCollection. 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. Determines whether the specified index is located within the CheckedListBox.CheckedIndexCollection. 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. or 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. Gets a value indicating whether access to the CheckedListBox.CheckedIndexCollection is synchronized (thread safe).

System_CAPS_pubinterfaceSystem_CAPS_privpropertyICollection.SyncRoot

This API supports the product infrastructure and is not intended to be used directly from your code. Gets an object that can be used to synchronize access to the collection of controls. 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 checked indexes collection is a subset of the indexes into the collection of all items in the CheckedListBox control. These indexes specify items in a checked or indeterminate state.

The following table is an example of the indexed collection of items in the control (all items contained in the control).

Index

Item

Check State

0

object 1

Unchecked

1

object 2

Checked

2

object 3

Unchecked

3

object 4

Indeterminate

4

object 5

Checked

Based on the previous example, the following table shows the indexed collection of indexes of checked items.

Index

Index of Item

0

1

1

3

2

4

The CheckedListBox class has two members that allow you to access the stored indexes, the Item property and the IndexOf method.

Based on the previous example, a call to the Item property with a parameter value of 1 returns a value of 3. A call to IndexOf with a parameter of 3 returns a value of 1.

The following example enumerates the checked items in the CheckedListBox.CheckedIndexCollection to see what check state an item is in. The example demonstrates using the GetItemCheckState method to set the check state of an item. The example also demonstrates using the CheckedIndices property to get the CheckedListBox.CheckedIndexCollection, and the CheckedItems property to get the CheckedListBox.CheckedItemCollection.

The first loop uses the GetItemCheckState method to get the CheckState of each checked item, given the index of the item. The second loop also uses GetItemCheckState, but uses the ListBox.ObjectCollection.IndexOf method to retrieve the index for the item.

private void WhatIsChecked_Click(object sender, System.EventArgs e) {
    // Display in a message box all the items that are checked.

    // First show the index and check state of all selected items.
    foreach(int indexChecked in checkedListBox1.CheckedIndices) {
        // The indexChecked variable contains the index of the item.
        MessageBox.Show("Index#: " + indexChecked.ToString() + ", is checked. Checked state is:" +
                        checkedListBox1.GetItemCheckState(indexChecked).ToString() + ".");
    }

    // Next show the object title and check state for each item selected.
    foreach(object itemChecked in checkedListBox1.CheckedItems) {

        // Use the IndexOf method to get the index of an item.
        MessageBox.Show("Item with title: \"" + itemChecked.ToString() + 
                        "\", is checked. Checked state is: " + 
                        checkedListBox1.GetItemCheckState(checkedListBox1.Items.IndexOf(itemChecked)).ToString() + ".");
    }

}

.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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