小编Mat*_*att的帖子

我已经查看了MSDN 示例，但仍然遇到问题。

我创建了一个超级简单的程序来将两个数字相乘，并在文本框中显示输出。现在我需要能够读取该文本框值并将该值放入文本文件中，当单击“保存到文件”按钮时打开“保存到文件”对话框。

Private Sub MutiplyBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MutiplyBtn.Click
    Dim FirstNum As Double = Num1.Text
    Dim SecondNum As Double = Num2.Text
    Dim Answer2 As Double = FirstNum * SecondNum
    Answerbox.Text = Answer2
End Sub

Private Sub SaveResultToFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveResultToFile.Click
    Dim myStream As Stream
    Dim saveFileDialog1 As New SaveFileDialog()

    saveFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
    saveFileDialog1.FilterIndex = 2
    saveFileDialog1.RestoreDirectory = True

    If saveFileDialog1.ShowDialog() = DialogResult.OK …

我已经对此做了一些研究,仍然无法使我的程序工作.我只需要检查文本框以查看用户输入是否是数值("."和"/"除外)

我的代码到目前为止,

 Private Sub Num1_KeyPress(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Num1.KeyPress
    Dim UserEntry As Boolean
    If UserEntry = IsNumeric(False) Then
        MessageBox.Show("That's not numeric!")
    End If
End Sub