Question

如何编写程序将文本框中的数字第一个与最后一个调换后在窗体上打印出调整后的数字

Answer 1

Private Sub command1_click()
Dim a, t As String
a = Text1.Text
t = Left(a, 1)
Mid(a, 1, 1) = Right(a, 1)
Mid(a, Len(a), 1) = t
Print a
End Sub

Answer 2

private void txtQuantity_KeyPress(object sender, KeyPressEventArgs e)
{
Regex regex = new Regex(@"^[0-9]+$");
if (e.KeyChar != '\b')
{
if (!regex.IsMatch(e.KeyChar.ToString()))
{
e.Handled = true;
}
}
}

txtQuantity 是文本框 在KeyPress事件中写 ，没有属性提够，只能写代码