1、appbar自定义leading

lib/widget/my_app_bar.dart

@@ -8,6 +8,7 @@ class MyPageAppBar extends StatelessWidget implements PreferredSizeWidget {
   final Function()? onBack;
   final List<Widget>? actions;
   final bool exitApp;
+  final Widget? leading;
 
   const MyPageAppBar({
     Key? key,
@@ -18,6 +19,7 @@ class MyPageAppBar extends StatelessWidget implements PreferredSizeWidget {
     this.onBack,
     this.actions,
     this.exitApp = false,
+    this.leading,
   }) : super(key: key);
 
   @override
@@ -29,6 +31,7 @@ class MyPageAppBar extends StatelessWidget implements PreferredSizeWidget {
       backgroundColor: backgroundColor,
       primary: primary,
       actions: actions,
+      leading: leading,
     );
   }