Question

之前我问过这个问题，但建议提供更多细节。这是问题所在：

我有一个名为CheckedList_Facility的CheckedListBox。此CheckedList_Facility中的所有项都来自SQL Server数据源。使用以下代码正确加载所有项目

Dim queryString As String = "SELECT Facility FROM Database.dbo.Facility "
Dim connection As New SqlConnection(connectionString)
Dim command As New SqlCommand(queryString, connection)
connection.Open()
Dim dataReader As SqlDataReader = command.ExecuteReader()
Dim source As New BindingSource
source.DataSource = dataReader
CheckedList_Facility.DataSource = source
CheckedList_Facility.ValueMember = "Facility"
connection.Close()

我想获取一系列已检查的项目。例如，

[X] AAA

[X] BBB

[] CCC

[] DDD

[X] EEE

然后列表应为“AAA”，“BBB”，“EEE”

要测试是否正确检索了项目，我使用按钮调用bt_GetItem，当按下此按钮时，msgbox会显示已检查的项目。使用此代码：
```
Dim itemChecked As Object
For Each itemChecked In CheckedList_Facility.CheckedItems
    MsgBox(itemChecked.ToString)
Next
```
但是，我只收到此错误消息

System.Data.Common.DataRecordInternal

从技术上讲，这可能不是错误，但我没有收到“AAA”，而是得到了这个

System.Data.Common.DataRecordInternal

Answer 1

因为您将checkedlistbox绑定到datareader，所以内部检查的对象实际上是{System.Data.Common.DataRecordInternal}而不是字符串或任何其他本机对象。您必须访问对象中的item属性才能获得所需的字符串，如下所示：

 MsgBox(itemChecked.item("Facility").ToString)

Answer 2

要显示“AAA”（字符串类型），您必须访问itemChecked对象的属性。由于您选择“设施”，我们将使用它。您收到的消息（ System.Data.Common.DataRecordInternal ）是对象itemChecked类型。

MsgBox(itemChecked.Items("Facility").ToString)

应输出“AAA”

Answer 3

For i As Integer = 0 To lbSit.Items.Count - 1
    If CType(lbSit.Items(i), DataRowView)(lbSit.ValueMember).ToString = "32" Then
        lbSit.SetItemChecked(i, True)
    End If
Next

Answer 4

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

从CheckedListBox VB.NET Winform中检索已检查的项目

4 个答案: