// 空白页勾选
        private void ICAP_AUTODISCARDBLANKPAGES_Checked(object sender, RoutedEventArgs e)
        {
            BlankImageThreshold.IsEnabled = true;
            UInt32  intValue = UInt32.Parse(BlankImageThreshold.Text) * 1024;
            CapInfo capInfo  = twSession.GetScannerCap(TwCap.ICAP_AUTODISCARDBLANKPAGES);

            capInfo.CurrentIntStr = intValue.ToString();
            capInfo.SetCap();
        }
 // 输入框失去焦点时保存值并设置
 private void BlankImageThreshold_LostFocus(object sender, RoutedEventArgs e)
 {
     // 获取空白页大小
     if (BlankImageThreshold.IsEnabled)
     {
         UInt32  intValue = UInt32.Parse(BlankImageThreshold.Text) * 1024;
         CapInfo capInfo  = twSession.GetScannerCap(TwCap.ICAP_AUTODISCARDBLANKPAGES);
         capInfo.CurrentIntStr = intValue.ToString();
         capInfo.SetCap();
     }
 }
        /// <summary>
        /// 设置一个值到控件和扫描仪
        /// </summary>
        /// <param name="control"></param>
        /// <param name="capInfo"></param>
        /// <returns></returns>
        private bool SetOneValue(Control control, CapInfo capInfo)
        {
            if (control is ComboBox)
            {
                ComboBox comboBox = control as ComboBox;
                bool     OK       = SetCurrentValueOfComboBox(comboBox, capInfo);

                if (OK) // 列表中有该值
                {
                    // 将该值设置到扫描仪
                    bool twOk = twSession.SetCapability(capInfo);
                    if (twOk)
                    {
                        return(true);
                    }
                }
                return(false);
            }
            else
            {
                CheckBox checkBox = control as CheckBox;
                if (capInfo.CurrentIntStr == null)
                {
                    capInfo.CurrentIntStr = "0";
                }
                if (capInfo.CapId == TwCap.ICAP_AUTODISCARDBLANKPAGES)
                {
                    {
                        Int32 intVal = Int32.Parse(capInfo.CurrentIntStr);
                        BlankImageThreshold.Text = (Math.Round((double)intVal / 1024)).ToString();
                    }
                    checkBox.IsChecked = !(capInfo.CurrentIntStr == "0");
                }
                else
                {
                    checkBox.IsChecked = (capInfo.CurrentIntStr == "1");
                }
                return(capInfo.SetCap());
            }
        }