断言失败：第 1205 行第 12 行：“<optimized out>”：不是真的

Question

我是 Flutter 新手，在 Syncfusion Calendar 小部件中遇到问题。任何帮助将不胜感激。这是我的构建小部件中的代码：

  return  Scaffold(
  resizeToAvoidBottomInset: false, // set it to false
  body: SafeArea(
    child: SfCalendar(
                view: CalendarView.month,
                dataSource:getData(),
                monthViewSettings: MonthViewSettings(showAgenda: true,),

      ),
  ),
);

'dart:ui/painting.dart': Failed assertion: line 1205 pos 12: '': is not true.

Here is the exception line:4 > child: SfCalendar()

这是堆栈跟踪：

**> 导致错误的相关小部件是：SfCalendar

file:///Users/kashif/Desktop/AppRack/clique/lib/bottomDashboard/Calendar.dart:47:16 When the exception was thrown, this was the stack: #2 Paint.color= (dart:ui/painting.dart:1205:12) #3 _AppointmentRenderObject._drawMonthAppointmentIndicator (package:syncfusion_flutter_calendar/src/calendar/appointment_layout/appointment_layout.dart:2042:15) #4 _AppointmentRenderObject._drawMonthAppointment (package:syncfusion_flutter_calendar/src/calendar/appointment_layout/appointment_layout.dart:1698:9) #5 _AppointmentRenderObject._drawCustomAppointmentView (package:syncfusion_flutter_calendar/src/calendar/appointment_layout/appointment_layout.dart:1662:11) #6 _AppointmentRenderObject.paint (package:syncfusion_flutter_calendar/src/calendar/appointment_layout/appointment_layout.dart:1614:7) #7 RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2396:7) #8 PaintingContext._repaintCompositedChild (package:flutter/src/rendering/object.dart:139:11) #9 PaintingContext.repaintCompositedChild (package:flutter/src/rendering/object.dart:100:5) #10 PipelineOwner.flushPaint (package:flutter/src/rendering/object.dart:975:29) #11 RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:464:19) #12 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:879:13) #13 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:328:5) #14 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1143:15) #15 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1080:9) #16 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:996:5) #20 _invoke (dart:ui/hooks.dart:163:10) #21 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:259:5) #22 _drawFrame (dart:ui/hooks.dart:126:31) (elided 5 frames from class _AssertionError and dart:async) The following RenderObject was being processed when the exception was fired: _AppointmentRenderObject#b4ead ... needs compositing ... parentData: (can use size) ... constraints: BoxConstraints(w=411.4, h=452.8) ... layer: OffsetLayer#2d0bc ... engine layer: OffsetEngineLayer#fc8e9 ... offset: Offset(0.0, 0.0) ... size: Size(411.4, 452.8) RenderObject: _AppointmentRenderObject#b4ead
needs compositing parentData: (can use size) constraints: BoxConstraints(w=411.4, h=452.8) layer: OffsetLayer#2d0bc engine layer: OffsetEngineLayer#fc8e9 offset: Offset(0.0, 0.0) size: Size(411.4, 452.8) ====================================================================================================**

Answer 1

根据我们提供的信息，我们已经检查过，我们无法重现上述问题。我们为此准备了一个简单的样本，基于给定的堆栈，我们怀疑样本中的约会颜色设置为空。请找到相同的代码片段。

代码片段：

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'package:syncfusion_flutter_calendar/calendar.dart';

void main() => runApp(AgendaView());

class AgendaView extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Agenda(),
    );
  }
}

class Agenda extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => AgendaExample();
}

class AgendaExample extends State<Agenda> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      resizeToAvoidBottomInset: false,
      body: SafeArea(
        child: SfCalendar(
          view: CalendarView.month,
          dataSource: MeetingDateSource(_getDataSource()),
          monthViewSettings: MonthViewSettings(showAgenda: true),
        ),
      ),
    );
  }
}

List<Meeting> _getDataSource() {
  List<Meeting> meets = <Meeting>[];
  meets.add(Meeting('Meeting', DateTime.now(),
      DateTime.now().add(Duration(minutes: 30)), Colors.pink, true));
  return meets;
}

class MeetingDateSource extends CalendarDataSource {
  MeetingDateSource(List<Meeting> source) {
    appointments = source;
  }
  @override
  String getSubject(int index) {
    return appointments![index].eventname;
  }

  @override
  DateTime getStartTime(int index) {
    return appointments![index].from;
  }

  @override
  DateTime getEndTime(int index) {
    return appointments![index].to;
  }

  @override
  Color getColor(int index) {
    return appointments![index].bgclr;
  }

  @override
  bool isAllDay(int index) {
    return appointments![index].bval;
  }
}

class Meeting {
  Meeting(this.eventname, this.from, this.to, this.bgclr, this.bval);
  String eventname;
  DateTime from;
  DateTime to;
  Color bgclr;
  bool bval;
}

如果分享的信息不符合您的要求，请您修改分享的示例以重现问题，或者如果可能的话，分享复制过程中使用的日历代码片段，以便我们进一步分析并为您提供最早可能的解决方案。

断言失败：第 1205 行第 12 行：“<optimized out>”：不是真的

Failed assertion: line 1205 pos 12: '<optimized out>': is not true

flutter

flutter-layout

syncfusion

syncfusion-calendar