Flutter 无法在物理设备上加载图像资产（但在模拟器上加载它就好了）

Posted 2023-02-23

【中文标题】Flutter 无法在物理设备上加载图像资产（但在模拟器上加载它就好了）

【英文标题】：Flutter unable to load image asset on physical device (but loading it just fine on the emulator)

【发布时间】：2020-02-08 15:52:31

【问题描述】：

我正在构建一个颤振应用程序，当我在手机上运行该应用程序时不会加载资产图像，但当我在模拟器上运行该应用程序时它加载正常。

这是我得到的错误：

> I/flutter (26364): ══╡ EXCEPTION CAUGHT BY IMAGE RESOURCE SERVICE
> ╞════════════════════════════════════════════════════ I/flutter
> (26364): The following assertion was thrown resolving an image codec:
> I/flutter (26364): Unable to load asset: images/diamond.png I/flutter
> (26364): I/flutter (26364): When the exception was thrown, this was
> the stack: I/flutter (26364): #0      PlatformAssetBundle.load
> (package:flutter/src/services/asset_bundle.dart:221:7) I/flutter
> (26364): <asynchronous suspension> I/flutter (26364): #1     
> AssetBundleImageProvider._loadAsync
> (package:flutter/src/painting/image_provider.dart:464:44) I/flutter
> (26364): <asynchronous suspension> I/flutter (26364): #2     
> AssetBundleImageProvider.load
> (package:flutter/src/painting/image_provider.dart:449:14) I/flutter
> (26364): #3      ImageProvider.resolve.<anonymous closure>.<anonymous
> closure>.<anonymous closure>
> (package:flutter/src/painting/image_provider.dart:316:48) I/flutter
> (26364): #4      ImageCache.putIfAbsent
> (package:flutter/src/painting/image_cache.dart:160:22) I/flutter
> (26364): #5      ImageProvider.resolve.<anonymous closure>.<anonymous
> closure> (package:flutter/src/painting/image_provider.dart:316:25)
> I/flutter (26364): (elided 13 frames from package dart:async)
> I/flutter (26364): I/flutter (26364): Image provider:
> AssetImage(bundle: null, name: "images/diamond.png") I/flutter
> (26364): Image key: AssetBundleImageKey(bundle:
> PlatformAssetBundle#5b025(), name: "images/diamond.png", I/flutter
> (26364):   scale: 1.0) I/flutter (26364):
> ════════════════════════════════════════════════════════════════════════════════════════════════════

这是我的 pubspec.yaml

flutter:
  uses-material-design: true
  assets:
    - images/

这里是 main.dart：

导入'package:flutter/material.dart';

void main() 
  runApp(
    MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          backgroundColor: Colors.blueGrey[900],
          title: Text('Picture Motivation'),
        ),
        body: Center(
          child: Image(
            image: AssetImage('images/diamond.png'),
          ),
        ),
      ),
    ),
  );

非常令人困惑的是为什么图像在模拟器上正确加载，而不是在物理设备上。有什么线索吗？

非常感谢。

【参考方案1】：

逐步执行此操作，这应该可以正常工作。基本上你做错了。

把图片放到assets文件夹，所以根是assets/diamond.png 或者如果您的资产文件夹中有另一个文件夹images，那么根目录是assets/images/diamond.png

pubspec.yaml

flutter:
   uses-material-design: true
   //you have to give the proper path in order to get the image in your UI
   assets: 
     - assets/images/diamond.png

用户界面代码：

//this is how your image calling work, you just have to copy the path, same as pubspec.yaml
Center(
   child: Image(
      image: AssetImage('assets/images/diamond.png'),
   )
)

我相信你现在就能得到图像了。让我知道这是否有帮助。

【讨论】：

你好@Alok！我可以确认，如果我在 pubspec.yaml 中指定图像的整个路径，它甚至可以在物理设备上正确呈现！非常感谢您的提示。顺便说一句，如果您像我以前那样指定资产文件夹名称，难道不应该获取所有文件吗？这就是它在文档上的内容...

嗯，准确来说，设备通常不会确认从您的文件夹中获取文件，您还需要指定文件夹的名称assets，这是一个很好的做法，并且不会让您感到困惑，也不会导致设备混乱。这里assets:，需要在路径中指定数据，你可以试试，不知道行不行，assets: images/diamond.png，其余的保持不变。