使用MessageBox清除文本框是按钮

Question

我想出了如何清除文本框，但是当我在MessageBox上按否时清除了该文本框。我想清除用户是否选择是。如果用户选择否那么我想什么都不做。

Private Sub BtnFah_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnFah.Click 
     Try 
      Dim intFah As Integer 
      intFah = CInt(TxtBoxTemp.Text) 
      intFah = (intFah * 9)/5 - 32 
      If MessageBox.Show(intFah.ToString & ControlChars.CrLf & "Would you like to start another temp conversion?", "Result", MessageBoxButtons.YesNo) Then 
       TxtBoxTemp.Text = String.Empty 
      End If 
     Catch 
      MessageBox.Show("Would you like to start another temp conversion?", "System Error", MessageBoxButtons.YesNo) 

     End Try 
    End Sub 

Answer 1

您需要比较DialogResult

Public Class Form1  
    Private Sub BtnFah_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnFah.Click 
     Try 
      Dim intFah As Integer 
      intFah = CInt(TxtBoxTemp.Text) 
      intFah = (intFah * 9)/5 - 32 
      If MessageBox.Show(intFah.ToString & ControlChars.CrLf & "Would you like to start another temp conversion?", "Result", MessageBoxButtons.YesNo) = DialogResult.Yes Then 
       TxtBoxTemp.Text = String.Empty 
      End If 
     Catch 
      MessageBox.Show("Would you like to start another temp conversion?", "System Error", MessageBoxButtons.YesNo) 

     End Try 
    End Sub 
End Class 

Answer 2

MessageBox.Show返回DialogResult。你应该为DialogResult.Yes检查：

If MessageBox.Show(...) = DialogResult.Yes Then 
    TxtBoxTemp.Text = String.Empty 
End If 

Answer 3

运用Q作为变量，暗淡的msgboxresult来取得了MSGBOX有结果，如果按是，文本框将会清楚，如果不是，那么它将返回或什么都不做

Dim q As MsgBoxResult 
      q = MsgBox("Your Question", vbYesNo) 
      If q = vbYes Then 
       TextBox1.Clear() 
      Else 
       Return 
      End If 

Answer 4

尝试......

If MessageBox.Show("Your Message", "Title", MessageBoxButtons.YesNo) = DialogResult.Yes Then 
textbox.clear() 
End If