i want to ask if it will be possible to do real time Critical Path Analysis by changing dates, duration and predecessors.
This tutorial (http://code.daypilot.org/68118/gantt-chart-tutorial-asp-net-sql-server-c-vb-net) uses the Scheduler control in Gantt mode (ViewType="Gantt") which has limited capabilities.
You might want to check the standalone Gantt chart control with advanced features:
It shows how to display the duration in a special column (http://doc.daypilot.org/gantt/columns/) and change the task duration using drag and drop (http://doc.daypilot.org/gantt/task-resizing/).
It also displays the task links/dependencies (http://doc.daypilot.org/gantt/links/).
It is possible to highlight the critical path by applying custom CSS classes to the links/tasks that are part of the critical path (see http://doc.daypilot.org/gantt/link-customization/). However, you need to calculate the critical path yourself (on the server side).