CheckedListBox.CheckedIndexCollection 类

定义

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

public class CheckedListBox.CheckedIndexCollection : System.Collections.IList

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

Public Class CheckedListBox.CheckedIndexCollection
Implements IList

继承

Object

CheckedListBox.CheckedIndexCollection

实现

ICollection IEnumerable IList

示例

以下示例枚举选中的项 CheckedListBox.CheckedIndexCollection ，以查看项处于哪个检查状态。 该示例演示如何使用 GetItemCheckState 该方法设置项的检查状态。 该示例还演示了如何使用 CheckedIndices 属性来获取 CheckedListBox.CheckedIndexCollection，以及 CheckedItems 用于获取的属性 CheckedListBox.CheckedItemCollection。

第一个循环使用 GetItemCheckState 该方法获取 CheckState 每个已检查项（给定项的索引）。 第二个循环也使用 GetItemCheckState，但使用该 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

选中的索引集合是控件中所有项的集合中的 CheckedListBox 索引子集。 这些索引指定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) 。

根据前面的示例，下表显示了已检查项索引的索引集合。

该 CheckedListBox 类具有两个成员，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 的属性的调用返回值 3。 使用参数 3 调用 IndexOf 将返回值 1。

属性

方法

显式接口实现

扩展方法

适用于

另请参阅

• CheckedIndices
• CheckedItems
• Items