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flutter - 如何在flutter中将缓存的图像添加到应用栏（使用cached_image_network）

问题描述

return Scaffold(
      appBar: AppBar(title: CachedNetworkImage(imageUrl: "https://cdn.pixabay.com/photo/2016/02/24/19/05/apples-1220574__340.png",
        width: 80.0,
        height: 80.0,


    )),

我使用缓存的网络图像在颤振应用栏中添加图像但它不起作用请帮助

这是控制台错误

Compiler message:
../../AppData/Roaming/Pub/Cache/hosted/pub.dartlang.org/cached_network_image-1.1.2+1/lib/src/scaled_file_image.dart:45:24: Error: The method 'ScaledFileImage.load' has fewer positional arguments than those of overridden method 'ImageProvider.load'.
  ImageStreamCompleter load(ScaledFileImage key) {
                       ^
../../Flutter/packages/flutter/lib/src/painting/image_provider.dart:403:24: Context: This is the overridden method ('load').
  ImageStreamCompleter load(T key, DecoderCallback decode);
                       ^
../../AppData/Roaming/Pub/Cache/hosted/pub.dartlang.org/cached_network_image-1.1.2+1/lib/src/cached_network_image_provider.dart:53:24: Error: The method 'CachedNetworkImageProvider.load' has fewer positional arguments than those of overridden method 'ImageProvider.load'.
  ImageStreamCompleter load(CachedNetworkImageProvider key) {
                       ^
../../Flutter/packages/flutter/lib/src/painting/image_provider.dart:403:24: Context: This is the overridden method ('load').
  ImageStreamCompleter load(T key, DecoderCallback decode);
                       ^
Exception: Errors during snapshot creation: null
#0      KernelSnapshot.build (package:flutter_tools/src/build_system/targets/dart.dart:230:7)
<asynchronous suspension>
#1      _BuildInstance._invokeInternal (package:flutter_tools/src/build_system/build_system.dart:526:25)
<asynchronous suspension>
#2      _BuildInstance.invokeTarget.<anonymous closure> (package:flutter_tools/src/build_system/build_system.dart:481:35)
#3      new Future.sync (dart:async/future.dart:222:31)
#4      AsyncMemoizer.runOnce (package:async/src/async_memoizer.dart:43:45)
#5      _BuildInstance.invokeTarget (package:flutter_tools/src/build_system/build_system.dart:481:21)
<asynchronous suspension>
<asynchronous suspension>
#6      BuildSystem.build (package:flutter_tools/src/build_system/build_system.dart:419:36)
#7      _AsyncAwaitCompleter.start (dart:async-patch/async_patch.dart:43:6)
#8      BuildSystem.build (package:flutter_tools/src/build_system/build_system.dart:400:28)
#9      buildWithAssemble (package:flutter_tools/src/bundle.dart:125:48)
#10     _AsyncAwaitCompleter.start (dart:async-patch/async_patch.dart:43:6)
#11     buildWithAssemble (package:flutter_tools/src/bundle.dart:99:31)
#12     BundleBuilder.build (package:flutter_tools/src/bundle.dart:75:11)
#13     _AsyncAwaitCompleter.start (dart:async-patch/async_patch.dart:43:6)
#14     BundleBuilder.build (package:flutter_tools/src/bundle.dart:52:21)
#15     BuildBundleCommand.runCommand (package:flutter_tools/src/commands/build_bundle.dart:126:25)
#16     _AsyncAwaitCompleter.start (dart:async-patch/async_patch.dart:43:6)
#17     BuildBundleCommand.runCommand (package:flutter_tools/src/commands/build_bundle.dart:97:42)
#18     FlutterCommand.verifyThenRunCommand (package:flutter_tools/src/runner/flutter_command.dart:557:18)
#19     _asyncThenWrapperHelper.<anonymous closure> (dart:async-patch/async_patch.dart:71:64)
#20     _rootRunUnary (dart:async/zone.dart:1132:38)
#21     _CustomZone.runUnary (dart:async/zone.dart:1029:19)
#22     _FutureListener.handleValue (dart:async/future_impl.dart:137:18)
#23     Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:678:45)
#24     Future._propagateToListeners (dart:async/future_impl.dart:707:32)
#25     Future._completeWithValue (dart:async/future_impl.dart:522:5)
#26     Future._asyncComplete.<anonymous closure> (dart:async/future_impl.dart:552:7)
#27     _rootRun (dart:async/zone.dart:1124:13)
#28     _CustomZone.run (dart:async/zone.dart:1021:19)
#29     _CustomZone.runGuarded (dart:async/zone.dart:923:7)
#30     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:963:23)
#31     _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#32     _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)
#33     _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:116:13)
#34     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:173:5)

Failed to build bundle.

FAILURE: Build failed with an exception.

* Where:
Script 'C:\Users\user\Flutter\packages\flutter_tools\gradle\flutter.gradle' line: 794

* What went wrong:
Execution failed for task ':app:compileFlutterBuildDebugArm'.
> Process 'command 'C:\Users\user\Flutter\bin\flutter.bat'' finished with non-zero exit value 1

请帮我找到解决方案。我想将缓存的网络图像添加到我的应用程序中。你有更好的解决方案吗？？？

如果你想要完整的代码，请告诉我我使用缓存的网络图像在颤振应用栏中添加图像但它不起作用请帮助

标签： flutterdart

解决方案

确保使用库的最新版本。就我而言，我尝试了下一个代码：cached_network_image: ^1.1.2在我的中pubspec.yaml，一切正常。

import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      title: 'AppBar Demo',
      debugShowCheckedModeBanner: false,
      home: MyApp()
    ),
  );
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: CachedNetworkImage(
          imageUrl: "https://cdn.pixabay.com/photo/2016/02/24/19/05/apples-1220574__340.png",
          width: 80.0,
          height: 80.0,
        )
      ),
      body: Center(
        child: Container(
          child: Text("asd"),
        ),
      ),
    );
  }
}

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