import 'package:flutter/material.dart'; //渐变效果 class CustomRouteJianBian extends PageRouteBuilder{ final Widget widget; CustomRouteJianBian(this.widget) :super( transitionDuration:const Duration(seconds:1), pageBuilder:( BuildContext context, Animation animation1, Animation animation2){ return widget; }, transitionsBuilder:( BuildContext context, Animation animation1, Animation animation2, Widget child){ return FadeTransition( opacity: Tween(begin:0.0,end :1.0).animate(CurvedAnimation( parent:animation1, curve:Curves.fastOutSlowIn )), child: child, ); } ); }