使用enableDrag的Flutter底表

Question

我设置了enableDrag=false，但bottomSheet仍可拖动，如何禁用拖动

var bottomSheet = BottomSheet(
        onClosing: () {},
        enableDrag: false,
        builder: (context) {
          return Container(
            color: Colors.white,
            alignment: Alignment.centerLeft,
            child: Text("aaaaa"),
          );
        });

Scaffold.of(context).showBottomSheet(bottomSheet.builder);