Visual Studio中的循環GUI

Question

您可以幫助我解決Visual Studio中循環GUI中的問題嗎？

需要發生的是把用於啓動文本框號1值，還必須將價值爲最終文本框的10號，也把價值步數文本框2.在下拉列表，你會選擇是否其環或做或時直到。應該出現在文本框中的for循環2 4 6 8 10和DO WHILE爲2 4 6 8和做，直到2 4 6 8

這裏是我的代碼，我不能做的問題

Public Class frmLimit 

    Private Sub btnProcess_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnProcess.Click 
     Dim ctr As Integer 
     For ctr = 0 To 50 
      txtDisplay.Text = txtDisplay.Text & ctr & vbNewLine 
     Next 
     If cmboType.SelectedIndex = 0 Then 
      MessageBox.Show("DO LOOP") 
     ElseIf cmboType.SelectedIndex = 1 Then 
      MessageBox.Show("WHILE LOOP") 
     ElseIf cmboType.SelectedIndex = 2 Then 
      MessageBox.Show("UNTIL LOOP") 
     End If 
    End Sub 

    Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click 
     txtStart.Clear() 
     txtEnd.Clear() 
     txtStep.Clear() 
     txtDisplay.Clear() 
     cmboType.SelectedIndex = -1 
    End Sub 

    Private Sub frmLimit_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing 
     Application.Exit() 
    End Sub 
End Class 

這是GUI

Answer 1

Private Sub btnProcess_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnProcess.Click 
    Dim ctr As Integer 

    If cmboType.SelectedIndex = 0 Then 
     If IsNumeric(txtStart.Text) And IsNumeric(txtEnd.Text) And IsNumeric(txtStep.Text) Then 
      For ctr = CInt(txtStart.Text) To CInt(txtEnd.Text) Step CInt(txtStep.Text) 
       txtDisplay.Text += ctr.ToString + " " 
      Next 

      txtDisplay.Text += vbNewLine 
     Else 
      'Error message 
     End If 

     MessageBox.Show("FOR LOOP") 
    ElseIf cmboType.SelectedIndex = 1 Then 
     MessageBox.Show("WHILE LOOP") 
    ElseIf cmboType.SelectedIndex = 2 Then 
     MessageBox.Show("UNTIL LOOP") 
    End If 
End Sub 

可以爲WHILE LOOP和Until LOOP這樣做。

瓦爾特