【发布时间】：2020-10-30 09:48:32
【问题描述】：
每次运行我的应用程序时都会出现编译错误。我有 3 个视图，主页、黑客页面和黑客屏幕。黑客页面：包含我想展示特定类别的生活黑客的卡片。 Hacks Screen 是我控制 Firestore 内容（每个类别的 hack）的文件。主页是应用程序的主页，其中包含卡片形式的类别列表。
我的主要目标是让用户点击特定类别，然后将所选类别作为 collectionPath 并将其放入 firestore。集合（collectionPath）.snapshots（）
例如：
在主页中，用户单击 Travel Category --> 它导航到 Hack Screen，collectionPath 的参数为“travel”，这是我在 firestore 上的集合名称，其中包含所有旅行类别 hack。 --> 再次导航到我创建了卡片和其他选项的 Hack 页面，然后逐一显示 Life Hacks of Travel（可通过按钮控制）
问题： 它正在删除此错误，并且当我从进程中删除 Hacks Screen 并使用随机文本直接导航到 Hack Page 时，它工作正常，所以我认为问题出在 Hack Screen 上。
注意：我已经初始化了 Firebase 和 Cloud Firestore 在 pubspec.yaml
这里是我的仓库的 Github 链接：https://github.com/pranjalchaplot/Hacks-For-Life 以提供更多便利。
错误是：
D/ColorViewRootUtil(20907): nav bar mode ignore false downX 513 downY 380 mScreenHeight 1520 mScreenWidth 720 mStatusBarHeight 36 globalScale 1.125 nav mode 0 rotation 0 event MotionEvent { action=ACTION_DOWN, actionButton=0, id[0]=0, x[0]=513.0, y[0]=380.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, classification=NONE, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=42425289, downTime=42425289, deviceId=3, source=0x1002, displayId=0 }
D/ColorViewRootUtil(20907): nav bar mode ignore false downX 499 downY 621 mScreenHeight 1520 mScreenWidth 720 mStatusBarHeight 36 globalScale 1.125 nav mode 0 rotation 0 event MotionEvent { action=ACTION_DOWN, actionButton=0, id[0]=0, x[0]=499.0, y[0]=621.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, classification=NONE, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=42426777, downTime=42426777, deviceId=3, source=0x1002, displayId=0 }
I/flutter (20907): Another exception was thrown: 'package:cloud_firestore/src/firestore.dart': Failed assertion: line 49 pos 12: 'app != null': is not true.
Performing hot reload...
Reloaded 2 of 792 libraries in 662ms.
D/ColorViewRootUtil(20907): nav bar mode ignore false downX 427 downY 633 mScreenHeight 1520 mScreenWidth 720 mStatusBarHeight 36 globalScale 1.125 nav mode 0 rotation 0 event MotionEvent { action=ACTION_DOWN, actionButton=0, id[0]=0, x[0]=427.0, y[0]=633.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, classification=NONE, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=42507154, downTime=42507154, deviceId=3, source=0x1002, displayId=0 }
I/flutter (20907): Another exception was thrown: 'package:cloud_firestore/src/firestore.dart': Failed assertion: line 49 pos 12: 'app != null': is not true.
Performing hot reload... -I/flutter (20907): ══╡ EXCEPTION CAUGHT BY WIDGETS
LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (20907): The following assertion was thrown building Builder(dirty):
I/flutter (20907): 'package:cloud_firestore/src/firestore.dart': Failed assertion: line 49 pos 12: 'app != null': is
I/flutter (20907): not true.
I/flutter (20907):
I/flutter (20907): The relevant error-causing widget was:
I/flutter (20907): MaterialApp
Hack_Page.dart：
import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:main/themes/style.dart';
import 'package:main/themes/theme_text.dart';
class HackPage extends StatelessWidget {
final Color backgroundColor;
final String hackText;
const HackPage({
Key key,
@required this.backgroundColor,
@required this.hackText,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Container(
alignment: Alignment.center,
child: Text(
"Hacks For Life",
style: GoogleFonts.oxygen(
textStyle: TextStyle(
fontWeight: FontWeight.bold,
),
),
),
),
actions: [
GestureDetector(
onTap: () {},
child: Container(
padding: EdgeInsets.symmetric(horizontal: 16),
child: Icon(Icons.share_outlined),
),
)
],
),
body: Container(
child: Column(
children: [
Container(
margin: EdgeInsets.only(top: 35),
child: Card(
color: backgroundColor,
margin: EdgeInsets.only(left: 20, right: 20),
child: Column(
mainAxisAlignment: MainAxisAlignment.end,
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Stack(
children: [
Container(
height: 400,
width: 360,
alignment: Alignment.center,
child: ListTile(
title: Text(
hackText,
style: ThemeText.headline,
textAlign: TextAlign.center,
),
tileColor: Colors.transparent,
),
),
],
),
],
),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0),
),
),
),
SizedBox(
height: 45,
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
GestureDetector(
onTap: () {},
child: Column(
children: [
Container(
padding: EdgeInsets.symmetric(horizontal: 26),
child: Icon(
Icons.chevron_left_rounded,
color: Colors.white,
size: 50,
)),
Container(
margin: EdgeInsets.only(top: 5),
child: Text(
"Previous",
style: simpleText(),
),
),
],
),
),
GestureDetector(
onTap: () {},
child: Column(
children: [
Container(
padding: EdgeInsets.symmetric(horizontal: 26),
child: Icon(
Icons.chevron_right_rounded,
color: Colors.white,
size: 50,
)),
Container(
margin: EdgeInsets.only(top: 5),
child: Text("Next", style: simpleText()),
)
],
),
)
],
)
],
),
),
);
}
}
Hack_Screen.dart：
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:main/views/hack_page.dart';
import 'package:random_color/random_color.dart';
class HackScreen extends StatelessWidget {
final FirebaseFirestore _firestore = FirebaseFirestore.instanceFor();
final RandomColor _randomColor = RandomColor();
final String collectionPath;
HackScreen({
Key key,
@required this.collectionPath,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder(
stream: _firestore.collection(collectionPath).snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return _LoadingIndicator();
return PageView.builder(
itemCount: snapshot.data.docs.length,
itemBuilder: (context, index) {
final document = snapshot.data.docs[index];
return HackPage(
backgroundColor: _randomColor.randomColor(
colorBrightness: ColorBrightness.dark,
),
hackText: document['hack'],
);
},
);
},
),
);
}
}
class _LoadingIndicator extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: CircularProgressIndicator(),
);
}
}
调用 Firebase Auth 后的错误：
I/flutter (20167): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (20167): The following assertion was thrown during performLayout():
I/flutter (20167): RenderCustomMultiChildLayoutBox object was given an infinite size during layout.
I/flutter (20167): This probably means that it is a render object that tries to be as big as possible, but it was put
I/flutter (20167): inside another render object that allows its children to
pick their own size.
I/flutter (20167): The nearest ancestor providing an unbounded height constraint is: RenderIndexedSemantics#b3286 relayoutBoundary=up3 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter (20167): creator: IndexedSemantics ← NotificationListener<KeepAliveNotification> ← KeepAlive ←
I/flutter (20167): AutomaticKeepAlive ← KeyedSubtree ← SliverList ← MediaQuery ← SliverPadding ← Viewport ←
I/flutter (20167): IgnorePointer-[GlobalKey#873d3] ← Semantics ← _PointerListener ← ⋯
I/flutter (20167): parentData: index=0; layoutOffset=0.0 (can use size)
I/flutter (20167): constraints: BoxConstraints(w=360.0, 0.0<=h<=Infinity)
I/flutter (20167): semantic boundary
I/flutter (20167): size: MISSING
I/flutter (20167): index: 0
I/flutter (20167): The constraints that applied to the RenderCustomMultiChildLayoutBox were:
I/flutter (20167): BoxConstraints(w=360.0, 0.0<=h<=Infinity)
I/flutter (20167): The exact size it was given was:
I/flutter (20167): Size(360.0, Infinity)
I/flutter (20167): See https://flutter.dev/docs/development/ui/layout/box-constraints for more information.
I/flutter (20167):
I/flutter (20167): The relevant error-causing widget was:
I/flutter (20167): Scaffold
I/flutter (20167): file:///D:/Work/Learning/Learning%20Flutter/LifeHacks_app/main/lib/views/hack_page.dart:18:12
I/flutter (20167):
I/flutter (20167): When the exception was thrown, this was the stack:
I/flutter (20167): #0 RenderBox.debugAssertDoesMeetConstraints.<anonymous closure> (package:flutter/src/rendering/box.dart:2060:9)
I/flutter (20167): #1 RenderBox.debugAssertDoesMeetConstraints (package:flutter/src/rendering/box.dart:2128:6)
I/flutter (20167): #2 RenderBox.size=.<anonymous closure> (package:flutter/src/rendering/box.dart:1846:7)
I/flutter (20167): #3 RenderBox.size= (package:flutter/src/rendering/box.dart:1848:6)
I/flutter (20167): #4 RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:401:5)
I/flutter (20167): #5 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #6 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #7 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #8 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #9 _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1306:11)
I/flutter (20167): #10 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #11 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #12 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #13 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #14 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #15 RenderSliverList.performLayout (package:flutter/src/rendering/sliver_list.dart:213:28)
I/flutter (20167): #16 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #17 RenderSliverEdgeInsetsPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:139:12)
I/flutter (20167): #18 RenderSliverPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:374:11)
I/flutter (20167): #19 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #20 RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:507:13)
I/flutter (20167): #21 RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1561:12)
I/flutter (20167): #22 RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1470:20)
I/flutter (20167): #23 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #24 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #25 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #26 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #27 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #28 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #29 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #30 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #31 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #32 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #33 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #34 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #35 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #36 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #37 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #38 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #39 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #40 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:111:14)
I/flutter (20167): #41 RenderObject.layout (package:flutter/src/rendering/object.dart:1777:7)
I/flutter (20167): #42 MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:171:12)
I/flutter (20167): #43 _ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:498:7)
I/flutter (20167): #44 MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:243:7)
I/flutter (20167): #45 RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:402:14)
I/flutter (20167): #46 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1634:7)
I/flutter (20167): #47 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:884:18)
I/flutter (20167): #48 RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:444:19)
I/flutter (20167): #49 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:907:13)
I/flutter (20167): #50 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:310:5)
I/flutter (20167): #51 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1117:15)
I/flutter (20167): #52 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1055:9)
I/flutter (20167): #53 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:971:5)
I/flutter (20167): #57 _invoke (dart:ui/hooks.dart:251:10)
I/flutter (20167): #58 _drawFrame (dart:ui/hooks.dart:209:3)
I/flutter (20167): (elided 3 frames from dart:async)
I/flutter (20167):
I/flutter (20167): The following RenderObject was being processed when the exception was fired: RenderCustomMultiChildLayoutBox#e1c48 relayoutBoundary=up7 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter (20167): creator: CustomMultiChildLayout ← AnimatedBuilder ← DefaultTextStyle ← AnimatedDefaultTextStyle ←
I/flutter (20167): _InkFeatures-[GlobalKey#87cbd ink renderer] ← NotificationListener<LayoutChangedNotification> ←
I/flutter (20167): PhysicalModel ← AnimatedPhysicalModel ← Material ← PrimaryScrollController ← _ScaffoldScope ←
I/flutter (20167): Scaffold ← ⋯
I/flutter (20167): parentData: <none> (can use size)
I/flutter (20167): constraints: BoxConstraints(w=360.0, 0.0<=h<=Infinity)
I/flutter (20167): size: Size(360.0, Infinity)
I/flutter (20167): This RenderObject had the following descendants (showing
up to depth 5):
I/flutter (20167): child 1: RenderFlex#c6502 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child 1: RenderPadding#61c12 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderSemanticsAnnotations#5631c NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderPadding#9c899 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderPhysicalShape#5fb12 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child 2: RenderConstrainedBox#38281 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (20167): child 3: RenderFlex#2b713 NEEDS-LAYOUT NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child 1: RenderSemanticsGestureHandler#a2514 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderPointerListener#d53c9 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderFlex#53d86 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child 2: RenderSemanticsGestureHandler#fbe23 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderPointerListener#eda8e NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderFlex#e1f6c NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child 2: RenderConstrainedBox#05703 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderSemanticsAnnotations#d4582 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderAnnotatedRegion<SystemUiOverlayStyle>#3c823 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderPhysicalModel#09da9 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: _RenderInkFeatures#bfd47 NEEDS-LAYOUT
NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child 3: RenderStack#f13cd NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child 1: RenderTransform#9e397 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (20167): child: RenderTransform#23b82 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (20167): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (20167): Another exception was thrown: _RenderInkFeatures object was given an infinite size during layout.
W/om.example.mai(20167): Accessing hidden field Ljava/net/Socket;->impl:Ljava/net/SocketImpl; (greylist, reflection, allowed)
I/flutter (20167): Another exception was thrown: RenderPhysicalModel object
was given an infinite size during layout.
W/om.example.mai(20167): Accessing hidden method Ldalvik/system/CloseGuard;->get()Ldalvik/system/CloseGuard; (greylist,core-platform-api, linking, allowed)
I/flutter (20167): Another exception was thrown: RenderRepaintBoundary object was given an infinite size during layout.
W/om.example.mai(20167): Accessing hidden method Ldalvik/system/CloseGuard;->open(Ljava/lang/String;)V (greylist,core-platform-api, linking, allowed)
W/om.example.mai(20167): Accessing hidden field Ljava/io/FileDescriptor;->descriptor:I (greylist, JNI, allowed)
I/flutter (20167): Another exception was thrown: RenderIndexedSemantics object was given an infinite size during layout.
W/om.example.mai(20167): Accessing hidden method Ljava/security/spec/ECParameterSpec;->setCurveName(Ljava/lang/String;)V (greylist, reflection, allowed)W/om.example.mai(20167): Accessing hidden method Ldalvik/system/BlockGuard;->getThreadPolicy()Ldalvik/system/BlockGuard$Policy; (greylist,core-platform-api, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Ldalvik/system/BlockGuard$Policy;->onNetwork()V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->getObject(Ljava/lang/Object;J)Ljava/lang/Object; (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->getInt(Ljava/lang/Object;J)I (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->getObject(Ljava/lang/Object;J)Ljava/lang/Object; (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putInt(Ljava/lang/Object;JI)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->getLong(Ljava/lang/Object;J)J (greylist,core-platform-api, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->getLong(Ljava/lang/Object;J)J (greylist,core-platform-api, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->getObject(Ljava/lang/Object;J)Ljava/lang/Object; (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/om.example.mai(20167): Accessing hidden method Lsun/misc/Unsafe;->putLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
【问题讨论】：
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在应用执行期间，在此调用之前与 Firestore 的连接是否正常？该错误表明您在实例化之前尝试调用某些东西，我看到您的注释说您已经在
pubspec.yaml文件中对 firestore 执行了此操作，但是我不确定这是实例化 Firestore 的正确位置，你能分享你的配置？另外，尝试在 HackScreen.dart 中创建一个新的 Firestore 实例，以测试它是否有效。 -
是的，我在任何我想的地方都实例化了 Firestore，但为了确保这里是我的仓库的 Github 链接：github.com/pranjalchaplot/Hacks-For-Life 以提供更多便利
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你只是在
pubspec.yaml中导入firestore的依赖，而不是实例化它。尝试使用final _firestore = Firestore.instance;而不是final FirebaseFirestore _firestore = FirebaseFirestore.instanceFor();这样做，如果它解决了问题，请告诉我。 -
好吧，它确实解决了错误部分，但它导致了一个空白屏幕，我的主要目标是让用户点击应用程序的任何类别，当他点击特定类别时，生活黑客是从 Firestore 数据库中检索。并相应地使用上一个和下一个按钮。你能告诉我哪里出错了吗？我已经更新了我的仓库中的代码，你检查一下。
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嗯，你收到任何错误日志了吗？另外，您是否能够实际获取数据？尝试记录它以确保您这样做了，这将告诉我们您的代码的 Firestore 部分是否正常工作，因为这可能有多种原因，并且没有错误消息很难确定根本原因。
标签： firebase flutter firebase-realtime-database google-cloud-firestore