Question

此代码过于重复！我必须重新编写这个代码到二十个！你们可以帮助我把它转变成一个循环，只需从textbox1移动到2到3等等吗？

    If CheckBox1.Checked = True Then
        frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
        frmLunchBoxMenu.txtOrder.AppendText(frmLunchBoxMenu.LineNumber.ToString + ".) An order of " + CheckBox1.Text & Environment.NewLine)
    End If
    If CheckBox2.Checked = True Then
        frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
        frmLunchBoxMenu.txtOrder.AppendText(frmLunchBoxMenu.LineNumber.ToString + ".) An order of " + CheckBox2.Text & Environment.NewLine)
    End If        If CheckBox1.Checked = True Then
        frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
        frmLunchBoxMenu.txtOrder.AppendText(frmLunchBoxMenu.LineNumber.ToString + ".) An order of " + CheckBox1.Text & Environment.NewLine)
    End If
    If CheckBox2.Checked = True Then
        frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
        frmLunchBoxMenu.txtOrder.AppendText(frmLunchBoxMenu.LineNumber.ToString + ".) An order of " + CheckBox2.Text & Environment.NewLine)
    End If
    If CheckBox3.Checked = True Then
        frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
        frmLunchBoxMenu.txtOrder.AppendText(frmLunchBoxMenu.LineNumber.ToString + ".) An order of " + CheckBox3.Text & Environment.NewLine)
    End If
    If CheckBox4.Checked = True Then
        frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
        frmLunchBoxMenu.txtOrder.AppendText(frmLunchBoxMenu.LineNumber.ToString + ".) An order of " + CheckBox4.Text & Environment.NewLine)
    End If
    If CheckBox5.Checked = True Then
        frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
        frmLunchBoxMenu.txtOrder.AppendText(frmLunchBoxMenu.LineNumber.ToString + ".) An order of " + CheckBox5.Text & Environment.NewLine)
    End If

这是有效的，感谢帮助人员，问题是直接演员。解决：

Public Class frmBeverages
Dim Range As Integer = 0
Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
    While Range < 14
        Range = Range + 1
        Dim chk As CheckBox =
        DirectCast(Me.Controls("Checkbox" & CStr(Range)), CheckBox)
        If chk.CheckState = CheckState.Checked Then
            frmLunchBoxMenu.LineNumber = frmLunchBoxMenu.LineNumber + 1
            frmLunchBoxMenu.txtOrder.AppendText(CStr(frmLunchBoxMenu.LineNumber) & ".) An order of " & chk.Text & Environment.NewLine)
        End If
    End While
    Close()
End Sub
End Class

Answer 1

Dim strOutput As String = ""
Dim intLineNumber As Integer = 0
For Each ctl As Control In Me.Controls
  If TypeOf ctl Is CheckBox Then
    Dim chk As CheckBox = DirectCast(ctl, CheckBox)
    If chk.Checked Then
      intLineNumber += 1
      strOutput &= intLineNumber.ToString + ".) An order of " + ctl.Text & vbCrLf
    End If
  End If
Next ctl
txtOrder.Text = strOutput

...但你也应该考虑使用CheckedListBox控件。这将允许您的菜单动态加载（从文本文件或数据库加载），您不需要管理多个复选框控件。

这是CheckedListBox版本......

Public Class frmLunchBoxMenu
  'Add a CheckedListBox, a Button, and a TextBox named txtOrder to the form
  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    CheckedListBox1.Items.Clear()
    CheckedListBox1.Items.Add("Hamburger")
    CheckedListBox1.Items.Add("Pizza")
    CheckedListBox1.Items.Add("Cola")
    CheckedListBox1.Items.Add("Chips")
    CheckedListBox1.Items.Add("Hot dog")
  End Sub


  Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim strOutput As String = ""
    Dim intLineNumber As Integer = 0
    For i As Integer = 0 To CheckedListBox1.Items.Count - 1
      If CheckedListBox1.GetItemChecked(i) Then
        intLineNumber += 1
        strOutput &= intLineNumber.ToString + ".) An order of " + CheckedListBox1.Items(i).ToString & vbCrLf
      End If
    Next i
    txtOrder.Text = strOutput
  End Sub

End Class

Answer 2

这可能是一种方法：

    Dim Range As Integer() =
        Enumerable.Range(1, 20).ToArray

    For Each n As Integer In Range

        Dim chk As CheckBox =
            DirectCast(Me.Controls("Checkbox" & CStr(n)), CheckBox) 
        ' Specify above the right ControlCollection if needed.

        If chk.Checked Then

            With frmLunchBoxMenu
                .LineNumber += 1
                .txtOrder.AppendText(CStr(frmLunchBoxMenu.LineNumber) &
                                     ".) An order of " & chk.Text &
                                     Environment.NewLine)
            End With

        End If

    Next n

将此重复语句转换为循环

2 个答案: