CheckedListBox.CheckedItemCollection 类

定义

public: ref class CheckedListBox::CheckedItemCollection : System::Collections::IList

public class CheckedListBox.CheckedItemCollection : System.Collections.IList

type CheckedListBox.CheckedItemCollection = class
    interface IList
    interface ICollection
    interface IEnumerable

Public Class CheckedListBox.CheckedItemCollection
Implements IList

继承

Object

CheckedListBox.CheckedItemCollection

实现

ICollection IEnumerable IList

示例

以下示例枚举 中 CheckedListBox.CheckedIndexCollection 选中的项，以查看项处于何种检查状态。 该示例演示如何使用 GetItemCheckState 方法设置项的检查状态。 该示例还演示如何使用 CheckedIndices 属性获取 CheckedListBox.CheckedIndexCollection，并使用 CheckedItems 属性获取 CheckedListBox.CheckedItemCollection。

给定项的索引，第一个循环使用 GetItemCheckState 方法获取 CheckState 每个已检查项的 。 第二个循环也使用 GetItemCheckState，但使用 ListBox.ObjectCollection.IndexOf 方法检索项的索引。

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.
   IEnumerator^ myEnum1 = checkedListBox1->CheckedIndices->GetEnumerator();
   while ( myEnum1->MoveNext() )
   {
      Int32 indexChecked =  *safe_cast<Int32^>(myEnum1->Current);
      
      // The indexChecked variable contains the index of the item.
      MessageBox::Show( String::Concat( "Index#: ", indexChecked, ", is checked. Checked state is: ", checkedListBox1->GetItemCheckState( indexChecked ), "." ) );
   }

   
   // Next show the Object* title and check state for each item selected.
   IEnumerator^ myEnum2 = checkedListBox1->CheckedItems->GetEnumerator();
   while ( myEnum2->MoveNext() )
   {
      Object^ itemChecked = safe_cast<Object^>(myEnum2->Current);
      
      // Use the IndexOf method to get the index of an item.
      MessageBox::Show( String::Concat( "Item with title: \"", itemChecked, "\", is checked. Checked state is: ", checkedListBox1->GetItemCheckState( checkedListBox1->Items->IndexOf( itemChecked ) ), "." ) );
   }
}

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() + ".");
    }
}

Private Sub WhatIsChecked_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles WhatIsChecked.Click
    ' Display in a message box all the items that are checked.
    Dim indexChecked As Integer
    Dim itemChecked As Object
    Const quote As String = """"

    ' First show the index and check state of all selected items.
    For Each 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

    ' Next show the object title and check state for each item selected.
    For Each itemChecked In CheckedListBox1.CheckedItems

        ' Use the IndexOf method to get the index of an item.
        MessageBox.Show("Item with title: " + quote + itemChecked.ToString() + quote + _
                        ", is checked. Checked state is: " + _
                        CheckedListBox1.GetItemCheckState(CheckedListBox1.Items.IndexOf(itemChecked)).ToString() + ".")
    Next

End Sub

注解

选中的项集合是控件中 CheckedListBox 所有项的子集;它仅包含处于选中状态或不确定状态的项。

下表是 控件中项的索引集合的示例， (控件) 中包含的所有项。

根据上一个示例，下表显示了选中项的索引集合。

类 CheckedListBox 具有两个成员，可用于访问存储的索引、 Item[] 属性和 IndexOf 方法。

根据前面的示例，对 Item[] 参数值为 1 的 属性的调用将返回对象 4。 使用对象 4 的参数调用 IndexOf 将返回值 1。