Question

我有2行checkboxes名为。

喜欢这样：

upper（ck18，ck17，ck16，ck15，ck14，ck13，ck12，ck11，ck21，ck22，ck23，ck24，ck25，ck26，ck27，ck28）

更低（ck38，ck37，ck36，ck35，ck34，ck33，ck32，ck31，ck41，ck42，ck43，ck44，ck45，ck46，ck47，ck48）

按此顺序排序：

按下shift键时，有一种简单的方法可以检查一系列复选框吗？（比如单词上的文字选择）=只按下第一个然后是最后一个，同时按下shift以自动标记中间复选框。

Answer 1

考虑到您在谈论Windows窗体，您可以使用以下代码：

Public Class Form1

   Private _upperChkList As List(Of CheckBox)
   Private _lowerChkList As List(Of CheckBox)
   Private _firstChkClickedIndex As Integer = -1
   Private _firstChkClickedState As CheckState = CheckState.Indeterminate

   Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load

      ' Stores all the upper CheckBoxes in their specific list.
      _upperChkList = New List(Of CheckBox) From
         {ck18, ck17, ck16, ck15, ck14, ck13, ck12, ck11,
         ck21, ck22, ck23, ck24, ck25, ck26, ck27, ck2}
      ' Stores all the lower CheckBoxes in their specific list.
      _lowerChkList = New List(Of CheckBox) From
         {ck38, ck37, ck36, ck35, ck34, ck33, ck32, ck31,
         ck41, ck42, ck43, ck44, ck45, ck46, ck47, ck48}

      ' Defines the Click event handler for all the CheckBoxes.
      For Each chk In _upperChkList
         AddHandler chk.Click, AddressOf UpperCheckBoxes_Click
      Next
      For Each chk In _lowerChkList
         AddHandler chk.Click, AddressOf LowerCheckBoxes_Click
      Next

   End Sub

   Private Sub UpperCheckBoxes_Click(sender As Object, e As EventArgs)

      ' Redirects to the procedure that manages the CheckBoxes selection, passing
      ' the desired list to be handled, the upper CheckBoxes list, in this case.
      OnCheckBoxesClick(sender, _upperChkList)

   End Sub

   Private Sub LowerCheckBoxes_Click(sender As Object, e As EventArgs)

      ' Redirects to the procedure that manages the CheckBoxes selection, passing
      ' the desired list to be handled, the lower CheckBoxes list, in this case.
      OnCheckBoxesClick(sender, _lowerChkList)

   End Sub

   Private Sub OnCheckBoxesClick(sender As Object, chkList As List(Of CheckBox))

      ' Converts the sender from Object to Checkbox.
      Dim chk = CType(sender, CheckBox)

      ' If Shift key is not pressed, stores the index of the 
      ' first CheckBox pressed, And its state.
      If Control.ModifierKeys <> Keys.Shift Then
         ' Searches the CheckBox being clicked in the list and returns its index.
         ' Since Shift key is not pressed, that will be the first CheckBox.
         _firstChkClickedIndex = chkList.FindIndex(Function(c) c.Equals(chk))
         _firstChkClickedState = chk.CheckState
         Return
      End If

      ' If it got here, Shift key is pressed, so, it must have
      ' a first CheckBox stored. If not, don't go on.
      If _firstChkClickedIndex < 0 Then
         Return
      End If
      ' If the state of the actual CheckBox is different than the 
      ' state of the first one, don't go on.
      If chk.CheckState <> _firstChkClickedState Then
         Return
      End If

      ' Searches the CheckBox being clicked in the list and returns its index.
      ' Since Shift key is pressed, that will be the last CheckBox.
      Dim lastChkClickedIndex = chkList.FindIndex(Function(c) c.Equals(chk))

      ' Checks if we are going from a lower to a higher index, or the contrary.
      Dim stepDirection As Integer = If(lastChkClickedIndex >= _firstChkClickedIndex, 1, -1)
      ' Iterates the list from the first to the last CheckBoxes clicked 
      ' and changes the state of all the CheckBoxes in between to match 
      ' the state of the first CheckBox clicked.
      For i = _firstChkClickedIndex To lastChkClickedIndex Step stepDirection
         chkList(i).CheckState = _firstChkClickedState
      Next

      ' Resets the first CheckBox variables.
      _firstChkClickedIndex = -1
      _firstChkClickedState = CheckState.Indeterminate

   End Sub

End Class

我猜测CheckBox会按照您在此处放置的顺序放置在表单中，因此，这就是我用来填充列表的顺序。如果这不是正确的视觉顺序，则必须修改它们添加到列表中的顺序。

Answer 2

按钮显示选中所有框，然后从按钮单击调用此子。

Private Sub CheckThemAll()
        For Each ctr As Control In Controls
            If TypeOf ctr Is CheckBox Then
                CType(ctr, CheckBox).Checked = True
            End If
        Next
End Sub

标记多个复选框

2 个答案: