Visual Basic-循环以在选中复选框时更新列表框

Question

我在选中复选框时无法更新列表框。我总共有 8 个“test_location”复选框，我希望列表框在选中位置时将项目添加到“Steps_Queue_List”并在“Test_Locations”数组中存储“1”。还想在未选中复选框时清除列表。到目前为止这是可行的，但我更愿意学习如何为此创建一个循环：

Private Sub Location_CheckBox_1_CheckedChanged(sender As Object, e As EventArgs) Handles Location_CheckBox_1.CheckedChanged
    If Location_CheckBox_1.Checked Then
        Test_Locations(0) = 1
        Steps_Queue_List.Items.Add("test for location" & 1, 1)

    ElseIf Location_CheckBox_1.Checked = False Then
        Test_Locations(0) = 0
        Steps_Queue_List.Items.RemoveAt(0)
    End If
End Sub

Private Sub Location_CheckBox_2_CheckedChanged(sender As Object, e As EventArgs) Handles Location_CheckBox_2.CheckedChanged
    If Location_CheckBox_2.Checked Then
        Test_Locations(1) = 1
        Steps_Queue_List.Items.Add("test for location" & 2, 2)

    ElseIf Location_CheckBox_2.Checked = False Then
        Test_Locations(1) = 0
        Steps_Queue_List.Items.RemoveAt(0)
    End If
End Sub

Private Sub Location_CheckBox_3_CheckedChanged(sender As Object, e As EventArgs) Handles Location_CheckBox_3.CheckedChanged
    If Location_CheckBox_3.Checked Then
        Test_Locations(2) = 1
        Steps_Queue_List.Items.Add("test for location" & 3, 3)

    ElseIf Location_CheckBox_3.Checked = False Then
        Test_Locations(2) = 0
        Steps_Queue_List.Items.RemoveAt(0)
    End If
End Sub

提前致谢。

Answer 1

您不需要循环，但您可以在一个方法中处理所有事情。

将 Checkboxes 的属性 Tag 设置为从 1 到 8 的渐进值，以匹配您希望在列表框中显示的文本值。

然后设置一个事件处理程序来管理所有 CheckBox 的所有 CheckBoxChanged 事件。

在此事件处理程序中检索标记并使用它来处理数组索引和要更新的列表框

' Handle all Checkbox changed with the same handler
Private Sub OnCheckBoxChanged(sender As Object, e As EventArgs) 
Handles Location_CheckBox_1.CheckedChanged,Location_CheckBox_2.CheckedChanged,
        Location_CheckBox_3.CheckedChanged,Location_CheckBox_4.CheckedChanged,
        Location_CheckBox_5.CheckedChanged,Location_CheckBox_6.CheckedChanged,
        Location_CheckBox_7.CheckedChanged,Location_CheckBox_8.CheckedChanged

    ' Discover which checkbox has been clicked
    Dim chk = DirectCast(sender, CheckBox)

    ' Now read the value of the Tag property of that checkbox
    Dim idx = Convert.ToInt32(chk.Tag)
    If chk.Checked Then
        Test_Locations(idx - 1) = 1
        Steps_Queue_List.Items.Add("test for location" & idx, idx)
    Else
        Test_Locations(idx - 1) = 0
        Steps_Queue_List.Items.RemoveAt(0)
    End If
End Sub