vb.net - 根据键数组检查 e.KeyChar

Question

这可以检查吗？我在 MSDN 或任何地方都找不到太多与此相关的帮助。我不想用大量的 if/else 来检查数字是否输入到这个文本框中，而是想将其全部放入数组或列表中，并对输入的内容执行简单的包含(不存在)。我想要它做的就是如果在文本框中输入了任何数字，则删除文本框中突出显示的空文本。

 Private Sub txt_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles fptSSN.KeyPress
        Dim i As Integer
        Dim keysList As List(Of Keys)
        Dim keys() As Keys = {Windows.Forms.Keys.D0, Windows.Forms.Keys.D1, Windows.Forms.Keys.D2, Windows.Forms.Keys.D3, Windows.Forms.Keys.D4, Windows.Forms.Keys.D5, Windows.Forms.Keys.D6, Windows.Forms.Keys.D7, Windows.Forms.Keys.D8, Windows.Forms.Keys.D9, Windows.Forms.Keys.NumPad0, Windows.Forms.Keys.NumPad1, Windows.Forms.Keys.NumPad2, Windows.Forms.Keys.NumPad3, Windows.Forms.Keys.NumPad4, Windows.Forms.Keys.NumPad5, Windows.Forms.Keys.NumPad6, Windows.Forms.Keys.NumPad7, Windows.Forms.Keys.NumPad8, Windows.Forms.Keys.NumPad9}

        keysList.AddRange(keys)

           If txt.Text = "         " And e.KeyChar = ?????????????? Then
                txt.Text = ""
            End If
        Next
    End Sub

Answer 1

由于您要查找数字，因此可以利用 IsNumeric() 函数:

    If IsNumeric(e.KeyChar) Then
        txt.Text = String.Empty
        e.Handled = True
    End If

如果您在清除文本框中不希望数字出现在文本框中，请设置 e.Handled = True。