V2.2.0 Null check operator used on a null value

[HongxiangShe]

2.2.0版本

 if (_enableFirstRefresh) {
      _firstRefreshHeader = FirstRefreshHeader(widget.firstRefreshWidget!);
      SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
        callRefresh();
      });
    }

当开启firstRefresh后, widget.firstRefreshWidget! 这里会因为把null强制非空而报错, 建议不用‘!’, 除非你非常非常确定他非null值

[wh8817221]

我也有同样的问题，作者改一下吧

[sobriver]

我也是

[xuelongqy]

v2.2.1已修复

[aldaspan]

I have updated flutter_easyrefresh to v2.2.1 and the problem still exists.
`../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:200:30: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.

• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  if (SchedulerBinding.instance!.schedulerPhase == SchedulerPhase.idle) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:203:28: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:675:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:718:28: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  if (SchedulerBinding.instance!.schedulerPhase == SchedulerPhase.idle) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:721:26: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:766:30: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:774:28: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/refresh_indicator.dart:788:32: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/header/header.dart:235:22: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/footer.dart:244:22: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:198:30: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  if (SchedulerBinding.instance!.schedulerPhase == SchedulerPhase.idle) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:201:28: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:596:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:663:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:705:28: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  if (SchedulerBinding.instance!.schedulerPhase == SchedulerPhase.idle) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:708:26: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:751:30: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:759:28: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/footer/load_indicator.dart:770:32: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!
  ^
  ../../FlutterDev/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_easyrefresh-2.2.1/lib/src/refresher.dart:293:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../FlutterDev/flutter/packages/flutter/lib/src/scheduler/binding.dart').
  SchedulerBinding.instance!.addPostFrameCallback((Duration timestamp) {
  ^`