解决设备断开，点击扫描，状态栏未更新且可以点击扫描的问题；BUG-810

app/scanner2/mainwindow.cpp

@@ -3400,8 +3400,28 @@ void MainWindow::on_act_acquire_triggered()
     HGResult ret = HGBASE_ERR_FAIL;
     if (nullptr != m_devUser)
     {
+        bool deviceIsOnline = true;
         ret = m_devUser->StartScan();
-        if (HGBASE_ERR_OK != ret)
+
+#if defined(HG_CMP_MSC)
+
+        if (HGTWAIN_ERR_DEVICEOFFLINE == ret)
+        {
+            deviceIsOnline = false;
+        }
+#else
+        if (HGSANE_ERR_DEVICEOFFLINE == ret)
+        {
+            deviceIsOnline = false;
+        }
+#endif
+
+        if (!deviceIsOnline)
+        {
+            deleteDevUser();
+        }
+
+        if (HGBASE_ERR_OK != ret && deviceIsOnline)
         {
             on_scanFinishEvent();
         }

modules/twain_user/HGTwainImpl.cpp

@@ -640,6 +640,11 @@ HGResult HGTwainDSImpl::Enable(HGBool showUI, HWND parent, HGDSEventFunc eventFu
 	USHORT ret = m_dsmImpl->m_pDSMProc(&m_dsmImpl->m_AppId, &m_iden, DG_CONTROL, DAT_USERINTERFACE, MSG_ENABLEDS, (TW_MEMREF)&twUI);
 	if (TWRC_SUCCESS != ret)
 	{
+        TW_STATUS status;
+        m_dsmImpl->m_pDSMProc(&m_dsmImpl->m_AppId, &m_iden, DG_CONTROL, DAT_STATUS, MSG_GET, (TW_MEMREF)&status);
+        if (status.ConditionCode == TWCC_CHECKDEVICEONLINE)
+            return HGTWAIN_ERR_DEVICEOFFLINE;
+
 		return HGTWAIN_ERR_FAIL;
 	}