Open Custom Webpart from “Add new item” Click from sharepoint list using c#

Question

I want to open Custom WebPart on click of "add new item" link (as shown in above image) in SharePoint list Programmatically.

Answer 1

You can edit the default new form.

1. Go to list ribbon and click on Form Web Parts. From drop down click on Default New Form.

2. This will open New form in Edit mode.
3. Add your custom webpart on the form and hide the original webpart.

Answer 2

This is possible by adding a custom action that can be to the Style Library. You would need to design your custom form programmatically in this custom action - JavaScript file and associate to this list.