如何验证文本框是否只允许 1 个小数点 - Windows Phone 8

Question

我想验证 TextBox 只允许 1 个小数点和最多 2 位小数位。仅对于数字验证，我正在使用 InputScope="Number"，但它无法避免粘贴字母，所以我也需要对粘贴进行任何验证（或者只是禁用粘贴）。例如，用户必须能够插入 23、23.1、23.12 等数字，而不是 23.123、23.1.2 等。

Answer 1

 private void tb1_KeyDown(object sender, KeyRoutedEventArgs e)
        {
            if (e.Key >= Windows.System.VirtualKey.Number0 && e.Key <= Windows.System.VirtualKey.Number9 || e.Key == Windows.System.VirtualKey.Decimal || e.Key == Windows.System.VirtualKey.GamepadY)
            {
                string strkey = e.Key.ToString().Substring(e.Key.ToString().Length - 1, e.Key.ToString().Length - (e.Key.ToString().Length - 1));
                if (e.Key >= Windows.System.VirtualKey.Number0 && e.Key <= Windows.System.VirtualKey.Number9)
                {
                    TextBox tb = sender as TextBox;
                    int cursorPosLeft = tb.SelectionStart;
                    int cursorPosRight = tb.SelectionStart + tb.SelectionLength;
                    string result1 = tb.Text.Substring(0, cursorPosLeft) + strkey + tb.Text.Substring(cursorPosRight);
                    string[] parts = result1.Split('.');
                    if (parts.Length > 1)
                    {
                        if (parts[1].Length > 2 || parts.Length > 2)
                        {
                            e.Handled = true;
                        }
                    }
                }
                if (((TextBox)sender).Text.Contains(".") && e.Key == Windows.System.VirtualKey.Decimal)
                {
                    e.Handled = true;
                }
            }
            else
            {
                e.Handled = true;
            }
            if (e.Key >= Windows.System.VirtualKey.A && e.Key <= Windows.System.VirtualKey.Z ||
                    e.Key == Windows.System.VirtualKey.Space)
            {
                e.Handled = true;
            }
        }