Flutter: How to open Drawer programmatically

Question

I want to open Drawer programmatically not by sliding it, how to disable that sliding functionality (touch functionality of Drawer)

Answer 1

Calling Scaffold.of doesn't work because the context doesn't contain the Scaffold. Some solutions above have ignored this, others have used GlobalKey. I believe the cleanest solution is wrapping the button in a Builder:

Scaffold(
   drawerEnableOpenDragGesture: false, // Prevent user sliding open
   appBar: AppBar(
      automaticallyImplyLeading: false,
      title: Text("Some Title"),
      actions: [
         Builder(builder: (context) => // Ensure Scaffold is in context
            IconButton(
               icon: Icon(Icons.settings),
               onPressed: () => Scaffold.of(context).openDrawer()
         )),
      ],
   ),
   // TODO ...
)