Question

这是调试控制台中的完整错误：

Launching lib\main.dart on Android SDK built for x86 in debug mode...
Built build\app\outputs\apk\debug\app-debug.apk.
I/FlutterActivityDelegate( 4158): onResume setting current activity to this
D/        ( 4158): HostConnection::get() New Host Connection established 0xdc74b680, tid 4178
D/EGL_emulation( 4158): eglMakeCurrent: 0xdc741300: ver 2 0 (tinfo 0xdc74c480)
F/libc    ( 4158): Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xd in tid 4177 (Thread-2), pid 4158 (le.startupnamer)
*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
Build fingerprint: 'google/sdk_gphone_x86/generic_x86:9/PPP4.180612.007/4860066:userdebug/dev-keys'
Revision: '0'
ABI: 'x86'
pid: 4158, tid: 4177, name: Thread-2  >>> com.example.startupnamer <<<
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xd
Cause: null pointer dereference
eax ca0a8aac  ebx ca0a8aac  ecx 0000000a  edx c9046c80
edi de6638d0  esi c90479f8
ebp c9046b58  esp c9046b58  eip c96e31d8
backtrace:
#00 pc 006981d8  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#01 pc 008f5b75  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#02 pc 008e87ea  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#03 pc 008f3ad6  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#04 pc 008e8b2f  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#05 pc 008ffb03  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#06 pc 008eb310  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#07 pc 008f3d98  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#08 pc 008e8b2f  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#09 pc 008eafc8  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#10 pc 008f997f  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#11 pc 008eaff8  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#12 pc 008fc81c  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#13 pc 008eaf69  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#14 pc 008f997f  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#15 pc 008eaff8  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#16 pc 008ef41e  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#17 pc 008f0570  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#18 pc 0091433e  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#19 pc 0092fad4  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#20 pc 00932f2a  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#21 pc 00934573  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#22 pc 00933d2b  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#23 pc 0093004a  /data/app/com.example.startupnamer-Doz3k_Pl0QfJtnmxYqiyHg==/lib/x86/libflutter.so
#24 pc 0000056b  <anonymous:c7680000>
Lost connection to device.
Exited (sigterm)

我正在使用带有Flutter扩展名的Visual Studio Code，但没有使用Dart扩展名。我还尝试在Android模拟器上运行Flutter应用，该模拟器是具有API 28 x86的Nexus 6。仿真性能设置为“硬件-GLES 2.0”。其余设置保留为默认设置。

在与Flutter结合使用之前，我先冷启动该模拟器，这是由于adb连接问题导致如果我正常启动该模拟器而无法加载该模拟器。可能不相关，但还是值得一提。

在命令行中输入flutter doctor -v将显示以下内容：

[√] Flutter (Channel beta, v0.5.1, on Microsoft Windows [Version 10.0.17134.112], locale en-AU)
    • Flutter version 0.5.1 at C:\dev\flutter
    • Framework revision c7ea3ca377 (6 weeks ago), 2018-05-29 21:07:33 +0200
    • Engine revision 1ed25ca7b7
    • Dart version 2.0.0-dev.58.0.flutter-f981f09760

[√] Android toolchain - develop for Android devices (Android SDK 28.0.1)
    • Android SDK at C:\Android\android-sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-28, build-tools 28.0.1
    • ANDROID_HOME = C:\Android\android-sdk
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
    • All Android licenses accepted.

[√] Android Studio (version 3.1)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 26.0.1
    • Dart plugin version 173.4700
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)

[√] IntelliJ IDEA Community Edition (version 2018.1)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2018.1.2
    • Flutter plugin version 26.0.2
    • Dart plugin version 181.4668.60

[!] VS Code, 64-bit edition (version 1.25.0)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Flutter extension not installed; install from
      https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[!] Connected devices
    ! No devices available

! Doctor found issues in 2 categories.

现在是实际问题了：

当我加载Flutter应用程序时，无论代码处于哪种状态，该应用程序都会从创建后第一次保存它时的状态启动。如果我尝试对代码进行任何更改（我只是更改主题颜色）并尝试热重装，则应用程序将崩溃，并显示我上面发布的错误。为什么会发生这种情况，我该怎么解决？

加载项目或不更改代码进行热加载时都没有错误。

感谢您的帮助。

编辑：我无法使用同一项目在Android Studio中复制此错误。此错误仅对我显示在Visual Studio代码中。

Answer 1

您发布的第一个错误是当机，应该为raised on GitHub。应该有某种方式来符号化堆栈跟踪（因此它具有真实的方法名称等），但是我找不到用于它的指令。我不确定这可能与this或this相同。

我正在使用带有Flutter扩展名的Visual Studio Code，但没有使用Dart扩展名。

在这里不相关，但是仅供参考，Flutter扩展依赖于Dart扩展，因此安装Flutter会自动安装Dart。

当我加载Flutter应用程序时，无论代码处于哪种状态，该应用程序都会从创建后第一次保存它时的状态启动。

这听起来像this issue；值得一提的是，您在那里拥有它来帮助收集信息（我不确定Flutter团队中是否有人能够在本地复制该信息以进行调试）。

编辑：我无法使用同一项目在Android Studio中复制此错误。此错误仅对我显示在Visual Studio代码中。

两个IDE都使用相同的工具，因此环境之间可能存在细微的差异（例如，我认为大多数人在IntelliJ / Android Studio中都没有调试器的情况下运行，但在VS Code中默认情况下带有调试器）。您可以在VS Code fairly easily中捕获日志，但我不知道IntelliJ / Android Studio是否具有可比较的功能。

Answer 2

我找到“ 与设备的连接断开”的原因

添加 contacts_service 依赖项

后，我发现了此问题

如果您安装了需要用户权限的任何插件，但尚未以编程方式获得权限，则发现此错误。

要手动解决此问题

在应用中手动转到应用信息和授予权限

要以编程方式解决此问题。

以编程方式获取用户权限，然后才能访问任何插件

Answer 3

我设法将其修复在我的机器上。对我来说，诀窍是切换稳定的频道并使用以下命令更新抖动：

-flutter upgrade

-flutter pub get

Answer 4

2个月以来，我一直出现此错误，我能够使用热重载模式。解决了此问题，只需更换我们的移动充电电缆并使用USB电缆进行调试，希望可以为您提供帮助，如果可以，请投票。< / p>

Answer 5

只需更新您的拍动

$ flutter升级--force

对我来说很好试试吧

Answer 6

我有类似的问题。升级对我没有帮助。

仅当我尝试从相机或画廊上传照片时，该应用程序才会失去连接。

错误-这是我的图片上传页面

W/ThreadedRenderer( 7044): ThreadedRenderer::detachAnimators pid = 7044 threadid = 7089
V/PhoneWindow( 7044): DecorView setVisiblity: visibility = 4, Parent = ViewRoot{2fd9ffd com.finde.med/com.finde.med.MainActivity,ident = 0}, this = DecorView@e0877a7[MainActivity]
W/ThreadedRenderer( 7044): ThreadedRenderer::detachAnimators pid = 7044 threadid = 7089
Lost connection to device.
Exited (sigterm)

代码片段

import 'dart:io';

import 'package:cached_network_image/cached_network_image.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'package:findemed/models/user.dart';
import 'package:findemed/pages/home.dart';
import 'package:findemed/widgets/progress.dart';
import 'package:geolocator/geolocator.dart';
import 'package:image_picker/image_picker.dart';
import 'package:path_provider/path_provider.dart';
import 'package:image/image.dart' as Im;
import 'package:uuid/uuid.dart';

class Upload extends StatefulWidget {
  final User currentUser;

  Upload({this.currentUser});

  @override
  _UploadState createState() => _UploadState();
}

class _UploadState extends State<Upload>
    with AutomaticKeepAliveClientMixin<Upload> {
  TextEditingController captionController = TextEditingController();
  TextEditingController locationController = TextEditingController();
  File file;
  bool isUploading = false;
  String postId = Uuid().v4();

  handleTakePhoto() async {
    Navigator.pop(context);
    File file = await ImagePicker.pickImage(
      source: ImageSource.camera,
      maxHeight: 675,
      maxWidth: 960,
    );
    setState(() {
      this.file = file;
    });
  }

  handleChooseFromGallery() async {
    Navigator.pop(context);
    File file = await ImagePicker.pickImage(source: ImageSource.gallery);
    setState(() {
      this.file = file;
    });
  }

  selectImage(parentContext) {
    return showDialog(
      context: parentContext,
      builder: (context) {
        return SimpleDialog(
          title: Text("Create Post"),
          children: <Widget>[
            SimpleDialogOption(
                child: Text("Photo with Camera"), onPressed: handleTakePhoto),
            SimpleDialogOption(
                child: Text("Image from Gallery"),
                onPressed: handleChooseFromGallery),
            SimpleDialogOption(
              child: Text("Cancel"),
              onPressed: () => Navigator.pop(context),
            )
          ],
        );
      },
    );
  }

  Container buildSplashScreen() {
    return Container(
      color: Theme.of(context).primaryColor.withOpacity(0.6),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          SvgPicture.asset('assets/images/upload.svg', height: 170.0),
          Padding(
            padding: EdgeInsets.only(top: 50.0),
            child: RaisedButton(
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(15.0),
                ),
                child: Text(
                  "Upload Image",
                  style: TextStyle(
                    color: Colors.white,
                    fontSize: 16.0,
                  ),
                ),
                color: Theme.of(context).accentColor,
                onPressed: () => selectImage(context)),
          ),
        ],
      ),
    );
  }

  clearImage() {
    setState(() {
      file = null;
    });
  }

  compressImage() async {
    final tempDir = await getTemporaryDirectory();
    final path = tempDir.path;
    Im.Image imageFile = Im.decodeImage(file.readAsBytesSync());
    final compressedImageFile = File('$path/img_$postId.jpg')
      ..writeAsBytesSync(Im.encodeJpg(imageFile, quality: 85));
    setState(() {
      file = compressedImageFile;
    });
  }

  Future<String> uploadImage(imageFile) async {
    StorageUploadTask uploadTask =
        storageRef.child("post_$postId.jpg").putFile(imageFile);
    StorageTaskSnapshot storageSnap = await uploadTask.onComplete;
    String downloadUrl = await storageSnap.ref.getDownloadURL();
    return downloadUrl;
  }

  createPostInFirestore(
      {String mediaUrl, String location, String description}) {
    postsRef
        .document(widget.currentUser.id)
        .collection("userPosts")
        .document(postId)
        .setData({
      "postId": postId,
      "ownerId": widget.currentUser.id,
      "username": widget.currentUser.username,
      "mediaUrl": mediaUrl,
      "description": description,
      "location": location,
      "timestamp": timestamp,
      "likes": {},
    });
  }

  handleSubmit() async {
    setState(() {
      isUploading = true;
    });
    await compressImage();
    String mediaUrl = await uploadImage(file);
    createPostInFirestore(
      mediaUrl: mediaUrl,
      location: locationController.text,
      description: captionController.text,
    );
    captionController.clear();
    locationController.clear();
    setState(() {
      file = null;
      isUploading = false;
      postId = Uuid().v4();
    });
  }

  Scaffold buildUploadForm() {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.white70,
        leading: IconButton(
            icon: Icon(Icons.arrow_back, color: Colors.black),
            onPressed: clearImage),
        title: Text(
          "Caption Post",
          style: TextStyle(color: Colors.black),
        ),
        actions: [
          FlatButton(
            onPressed: isUploading ? null : () => handleSubmit(),
            child: Text(
              "Post",
              style: TextStyle(
                color: Colors.blueAccent,
                fontWeight: FontWeight.bold,
                fontSize: 20.0,
              ),
            ),
          ),
        ],
      ),
      body: ListView(
        children: <Widget>[
          isUploading ? linearProgress(context) : Text(""),
          Container(
            height: 220.0,
            width: MediaQuery.of(context).size.width * 0.8,
            child: Center(
              child: AspectRatio(
                aspectRatio: 16 / 9,
                child: Container(
                  decoration: BoxDecoration(
                    image: DecorationImage(
                      fit: BoxFit.cover,
                      image: FileImage(file),
                    ),
                  ),
                ),
              ),
            ),
          ),
          Padding(
            padding: EdgeInsets.only(top: 10.0),
          ),
          ListTile(
            leading: CircleAvatar(
              backgroundImage:
                  CachedNetworkImageProvider(widget.currentUser.photoUrl),
            ),
            title: Container(
              width: 250.0,
              child: TextField(
                controller: captionController,
                decoration: InputDecoration(
                  hintText: "Write a caption...",
                  border: InputBorder.none,
                ),
              ),
            ),
          ),
          Divider(),
          ListTile(
            leading: Icon(
              Icons.pin_drop,
              color: Colors.orange,
              size: 35.0,
            ),
            title: Container(
              width: 250.0,
              child: TextField(
                controller: locationController,
                decoration: InputDecoration(
                  hintText: "Where was this photo taken?",
                  border: InputBorder.none,
                ),
              ),
            ),
          ),
          Container(
            width: 200.0,
            height: 100.0,
            alignment: Alignment.center,
            child: RaisedButton.icon(
              label: Text(
                "Usef Current Location",
                style: TextStyle(color: Colors.white),
              ),
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(30.0),
              ),
              color: Colors.blue,
              onPressed: getUserLocation,
              icon: Icon(
                Icons.my_location,
                color: Colors.white,
              ),
            ),
          ),
        ],
      ),
    );
  }

  getUserLocation() async {
    Position position = await Geolocator()
        .getCurrentPosition(desiredAccuracy: LocationAccuracy.high);
    List<Placemark> placemarks = await Geolocator()
        .placemarkFromCoordinates(position.latitude, position.longitude);
    Placemark placemark = placemarks[0];
    String completeAddress =
        '${placemark.subThoroughfare} ${placemark.thoroughfare}, ${placemark.subLocality} ${placemark.locality}, ${placemark.subAdministrativeArea}, ${placemark.administrativeArea} ${placemark.postalCode}, ${placemark.country}';
    print(completeAddress);
    String formattedAddress = "${placemark.locality}, ${placemark.country}";
    locationController.text = formattedAddress;
  }

  bool get wantKeepAlive => true;

  @override
  Widget build(BuildContext context) {
    super.build(context);

    return file == null ? buildSplashScreen() : buildUploadForm();
  }
}

我也收到有关图像选择器的警告

{
    "resource": "/F:/_dev/findemed/lib/pages/upload.dart",
    "owner": "dart",
    "code": {
        "value": "deprecated_member_use",
        "target": {
            "$mid": 1,
            "external": "https://dart.dev/tools/diagnostic-messages#deprecated_member_use",
            "path": "/tools/diagnostic-messages",
            "scheme": "https",
            "authority": "dart.dev",
            "fragment": "deprecated_member_use"
        }
    },
    "severity": 2,
    **"message": "' pickImage ' is deprecated and shouldn't be used. Use imagePicker.getImage() method instead..\nTry replacing the use of the deprecated member with the replacement.",
    "source": "dart",
    "startLineNumber": 47,
    "startColumn": 35,
    "endLineNumber": 47,
    "endColumn": 44,
    "tags": [
        2
    ]
}
```**

颤振：热重载后出现“与设备的连接丢失”错误

6 个答案: