CheckedListBox.GetItemCheckState 方法
返回指示当前项的复选状态的值。
**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）
语法
声明
Public Function GetItemCheckState ( _
index As Integer _
) As CheckState
用法
Dim instance As CheckedListBox
Dim index As Integer
Dim returnValue As CheckState
returnValue = instance.GetItemCheckState(index)
public CheckState GetItemCheckState (
int index
)
public:
CheckState GetItemCheckState (
int index
)
public CheckState GetItemCheckState (
int index
)
public function GetItemCheckState (
index : int
) : CheckState
参数
- index
要获取其选中值的项的索引。
返回值
CheckState 值之一。
异常
| 异常类型 | 条件 |
|---|---|
指定的 index 小于零。 - 或 - 指定的 index 大于或等于列表中项的计数。 |
备注
GetItemCheckState 方法提供了在给定索引的情况下获取某项的 CheckState 值的能力。如果永远都不会将一个项的复选状态设置为 Indeterminate，则可使用 GetItemChecked 方法。
示例
下面的示例枚举在 CheckedListBox.CheckedIndexCollection 中选中的项以查看项的复选状态。本示例演示了使用 GetItemCheckState 方法设置项的复选状态。本示例还演示了使用 CheckedIndices 属性获取 CheckedListBox.CheckedIndexCollection，以及使用 CheckedItems 属性获取 CheckedListBox.CheckedItemCollection。
第一个循环使用 GetItemCheckState 方法获取每个选中项的 CheckState（给定该项的索引）。第二个循环也使用 GetItemCheckState，但是使用 ListBox.ObjectCollection.IndexOf 方法来检索该项的索引。
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
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() + ".");
}
}
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.
IEnumerator objEnum = checkedListBox1.get_CheckedIndices().
GetEnumerator();
while (objEnum.MoveNext()) {
int indexChecked = (int)(Int32)(objEnum.get_Current());
// The indexChecked variable contains the index of the item.
MessageBox.Show("Index#: " + (Int32)indexChecked
+ ", is checked. Checked state is:"
+ checkedListBox1.GetItemCheckState(indexChecked).ToString()
+ ".");
}
// Next show the object title and check state for each item selected.
for (int iCtr = 0;
iCtr < checkedListBox1.get_CheckedItems().get_Count();
iCtr++) {
Object itemChecked =
checkedListBox1.get_CheckedItems().get_Item(iCtr);
// 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.get_Items().IndexOf(itemChecked)).ToString()
+ ".");
}
} //whatIsChecked_Click
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
请参见
参考
CheckedListBox 类
CheckedListBox 成员
System.Windows.Forms 命名空间
GetItemChecked
CheckState