Flutter：无法加载资源

Question

我无法将图像作为背景上传到容器，我已将图像添加到资产文件夹中并将其添加到 pubspec.yaml 并向我显示该错误：

I/flutter ( 6664): ??? EXCEPTION CAUGHT BY IMAGE RESOURCE SERVICE ?????????????????????????????????????????????????????
I/flutter ( 6664): The following assertion was thrown resolving an image codec:
I/flutter ( 6664): Unable to load asset: assets/images/img.png
I/flutter ( 6664): 
I/flutter ( 6664): When the exception was thrown, this was the stack:
I/flutter ( 6664): #0      PlatformAssetBundle.load (package:flutter/src/services/asset_bundle.dart:221:7)
I/flutter ( 6664): <asynchronous suspension>
I/flutter ( 6664): #1      AssetBundleImageProvider._loadAsync (package:flutter/src/painting/image_provider.dart:484:44)
I/flutter ( 6664): #2      AssetBundleImageProvider.load (package:flutter/src/painting/image_provider.dart:469:14)
I/flutter ( 6664): #3      ImageProvider.resolve.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:flutter/src/painting/image_provider.dart:327:17)
I/flutter ( 6664): #4      ImageCache.putIfAbsent (package:flutter/src/painting/image_cache.dart:160:22)
I/flutter ( 6664): #5      ImageProvider.resolve.<anonymous closure>.<anonymous closure> (package:flutter/src/painting/image_provider.dart:325:84)
I/flutter ( 6664): (elided 13 frames from package dart:async)
I/flutter ( 6664): 
I/flutter ( 6664): Image provider: AssetImage(bundle: null, name: "assets/images/img.png")
I/flutter ( 6664): Image key: AssetBundleImageKey(bundle: PlatformAssetBundle#99877(), name: "assets/images/img.png",
I/flutter ( 6664):   scale: 1.0)
I/flutter ( 6664): ????????????????????????????????????????????????????????????????????????????????????????????????????

代码 ：

body: Form(
          child: Column(
            children: <Widget>[
               Container(
                 decoration: BoxDecoration(
                   image: DecorationImage(
                     image: AssetImage("assets/images/img.png"),
                     fit: BoxFit.cover,
                   ),
                 ),

我已经添加了

assets:
  - assets/images/

到 pubspec.yaml

图像文件夹

并在

assets:
  - assets/images/img.png

---

I/flutter ( 6664): ??? EXCEPTION CAUGHT BY IMAGE RESOURCE SERVICE ?????????????????????????????????????????????????????
I/flutter ( 6664): The following assertion was thrown resolving an image codec:
I/flutter ( 6664): Unable to load asset: assets/images/img.png
I/flutter ( 6664): 
I/flutter ( 6664): When the exception was thrown, this was the stack:
I/flutter ( 6664): #0      PlatformAssetBundle.load (package:flutter/src/services/asset_bundle.dart:221:7)
I/flutter ( 6664): <asynchronous suspension>
I/flutter ( 6664): #1      AssetBundleImageProvider._loadAsync (package:flutter/src/painting/image_provider.dart:484:44)
I/flutter ( 6664): #2      AssetBundleImageProvider.load (package:flutter/src/painting/image_provider.dart:469:14)
I/flutter ( 6664): #3      ImageProvider.resolve.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:flutter/src/painting/image_provider.dart:327:17)
I/flutter ( 6664): #4      ImageCache.putIfAbsent (package:flutter/src/painting/image_cache.dart:160:22)
I/flutter ( 6664): #5      ImageProvider.resolve.<anonymous closure>.<anonymous closure> (package:flutter/src/painting/image_provider.dart:325:84)
I/flutter ( 6664): (elided 13 frames from package dart:async)
I/flutter ( 6664): 
I/flutter ( 6664): Image provider: AssetImage(bundle: null, name: "assets/images/img.png")
I/flutter ( 6664): Image key: AssetBundleImageKey(bundle: PlatformAssetBundle#c1182(), name: "assets/images/img.png",
I/flutter ( 6664):   scale: 1.0)
I/flutter ( 6664): ????????????????????????????????????????????????????????????????????????????????????????????????????

Answer 1

你需要这样添加

flutter:
  assets:
    - assets/images/img.png

Answer 2

就我而言，我需要包属性，因为图像位于我的库项目中并且我正在运行示例项目。

package: [你的父目录或项目名称]

例如。我的项目名称是“flutter_demo”

AssetImage('assets/images/ic_welcome.png', package: 'flutter_demo'),

pubspect.yaml

flutter:
  assets:
    - assets/images/

目录结构：

flutter_demo
  -- assets
    -- images
      -- ic_welcome.png