<p dir="auto">The class <a href="https://docs.flutter.io/flutter/widgets/AnimatedBuilder-class.html" rel="nofollow"><code class="notranslate">AnimatedBuilder</code></a> should have its name replaced. As it is not related to animation in reality.</p>
<p dir="auto">For example, the following is possible :</p>
<div class="highlight highlight-source-dart notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="final valueNotifier = ValueNotifier(0);

AnimatedBuilder(
  animation: valueNotifier,
  builder: (context, _) {
    return Text(valueNotifier.value.toString());
  },
)"><pre class="notranslate"><span class="pl-k">final</span> valueNotifier <span class="pl-k">=</span> <span class="pl-c1">ValueNotifier</span>(<span class="pl-c1">0</span>);

<span class="pl-c1">AnimatedBuilder</span>(
  animation<span class="pl-k">:</span> valueNotifier,
  builder<span class="pl-k">:</span> (context, _) {
    <span class="pl-k">return</span> <span class="pl-c1">Text</span>(valueNotifier.value.<span class="pl-en">toString</span>());
  },
)</pre></div>
<p dir="auto">Same goes for <code class="notranslate">ScrollController</code>, ...</p>
<p dir="auto">I suggest to rename it to <code class="notranslate">ListenableBuilder</code> as it makes more sense.</p>
<p dir="auto">hi, i have met the problem when i run the lib/main.dart, the below is crash log</p>
<p dir="auto">Flutter crash report; please file at <a href="https://github.com/flutter/flutter/issues">https://github.com/flutter/flutter/issues</a>.</p>
<h2 dir="auto">command</h2>
<p dir="auto">flutter run</p>
<h2 dir="auto">exception</h2>
<p dir="auto">FormatException: FormatException: Bad UTF-8 encoding 0xc3 (at offset 126)</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="#0      _Utf8Decoder.convert (dart:convert/utf.dart:484:15)
#1      _Utf8ConversionSink.addSlice (dart:convert/string_conversion.dart:345:14)
#2      _Utf8ConversionSink.add (dart:convert/string_conversion.dart:341:5)
#3      _ConverterStreamEventSink.add (dart:convert/chunked_conversion.dart:86:18)
#4      _SinkTransformerStreamSubscription._handleData (dart:async/stream_transformers.dart:120:24)
#5      _rootRunUnary (dart:async/zone.dart:1132:38)
#6      _CustomZone.runUnary (dart:async/zone.dart:1029:19)
#7      _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
#8      _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:336:11)
#9      _BufferingStreamSubscription._add (dart:async/stream_impl.dart:263:7)
#10     _SyncStreamController._sendData (dart:async/stream_controller.dart:763:19)
#11     _StreamController._add (dart:async/stream_controller.dart:639:7)
#12     _StreamController.add (dart:async/stream_controller.dart:585:5)
#13     _Socket._onData (dart:io/runtime/binsocket_patch.dart:1721:41)
#14     _rootRunUnary (dart:async/zone.dart:1136:13)
#15     _CustomZone.runUnary (dart:async/zone.dart:1029:19)
#16     _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
#17     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:336:11)
#18     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:263:7)
#19     _SyncStreamController._sendData (dart:async/stream_controller.dart:763:19)
#20     _StreamController._add (dart:async/stream_controller.dart:639:7)
#21     _StreamController.add (dart:async/stream_controller.dart:585:5)
#22     new _RawSocket.&lt;anonymous closure&gt; (dart:io/runtime/binsocket_patch.dart:1283:33)
#23     _NativeSocket.issueReadEvent.issue (dart:io/runtime/binsocket_patch.dart:826:14)
#24     _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#25     _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)
#26     _runPendingImmediateCallback (dart:isolate/runtime/libisolate_patch.dart:115:13)
#27     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:172:5)"><pre class="notranslate"><code class="notranslate">#0      _Utf8Decoder.convert (dart:convert/utf.dart:484:15)
#1      _Utf8ConversionSink.addSlice (dart:convert/string_conversion.dart:345:14)
#2      _Utf8ConversionSink.add (dart:convert/string_conversion.dart:341:5)
#3      _ConverterStreamEventSink.add (dart:convert/chunked_conversion.dart:86:18)
#4      _SinkTransformerStreamSubscription._handleData (dart:async/stream_transformers.dart:120:24)
#5      _rootRunUnary (dart:async/zone.dart:1132:38)
#6      _CustomZone.runUnary (dart:async/zone.dart:1029:19)
#7      _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
#8      _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:336:11)
#9      _BufferingStreamSubscription._add (dart:async/stream_impl.dart:263:7)
#10     _SyncStreamController._sendData (dart:async/stream_controller.dart:763:19)
#11     _StreamController._add (dart:async/stream_controller.dart:639:7)
#12     _StreamController.add (dart:async/stream_controller.dart:585:5)
#13     _Socket._onData (dart:io/runtime/binsocket_patch.dart:1721:41)
#14     _rootRunUnary (dart:async/zone.dart:1136:13)
#15     _CustomZone.runUnary (dart:async/zone.dart:1029:19)
#16     _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
#17     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:336:11)
#18     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:263:7)
#19     _SyncStreamController._sendData (dart:async/stream_controller.dart:763:19)
#20     _StreamController._add (dart:async/stream_controller.dart:639:7)
#21     _StreamController.add (dart:async/stream_controller.dart:585:5)
#22     new _RawSocket.&lt;anonymous closure&gt; (dart:io/runtime/binsocket_patch.dart:1283:33)
#23     _NativeSocket.issueReadEvent.issue (dart:io/runtime/binsocket_patch.dart:826:14)
#24     _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#25     _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)
#26     _runPendingImmediateCallback (dart:isolate/runtime/libisolate_patch.dart:115:13)
#27     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:172:5)
</code></pre></div>
<h2 dir="auto">flutter doctor</h2>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="�[32m[✓]�[39m Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.17134.471], locale zh-CN)
    �[32m•�[39m Flutter version 1.0.0 at C:\flutter
    �[32m•�[39m Framework revision 5391447fae (2 weeks ago), 2018-11-29 19:41:26 -0800
    �[32m•�[39m Engine revision 7375a0f414
    �[32m•�[39m Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)

�[32m[✓]�[39m Android toolchain - develop for Android devices (Android SDK 28.0.3)
    �[32m•�[39m Android SDK at D:\AndroidSdk
    �[32m•�[39m Android NDK location not configured (optional; useful for native profiling support)
    �[32m•�[39m Platform android-28, build-tools 28.0.3
    �[32m•�[39m Java binary at: D:\DevelopSoftware\Android Studio\jre\bin\java
    �[32m•�[39m Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
    �[32m•�[39m All Android licenses accepted.

�[32m[✓]�[39m Android Studio (version 3.2)
    �[32m•�[39m Android Studio at D:\DevelopSoftware\Android Studio
    �[32m•�[39m Flutter plugin version 31.2.1
    �[32m•�[39m Dart plugin version 181.5656
    �[32m•�[39m Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)

�[32m[✓]�[39m IntelliJ IDEA Ultimate Edition (version 2018.3)
    �[32m•�[39m IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA 2018.3
    �[32m•�[39m Flutter plugin version 31.2.4
    �[32m•�[39m Dart plugin version 183.4733

�[32m[✓]�[39m Connected device (1 available)
    �[32m•�[39m BKL AL20 • P7C0218109001735 • android-arm64 • Android 8.0.0 (API 26)

�[32m•�[39m No issues found!"><pre class="notranslate"><code class="notranslate">�[32m[✓]�[39m Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.17134.471], locale zh-CN)
    �[32m•�[39m Flutter version 1.0.0 at C:\flutter
    �[32m•�[39m Framework revision 5391447fae (2 weeks ago), 2018-11-29 19:41:26 -0800
    �[32m•�[39m Engine revision 7375a0f414
    �[32m•�[39m Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)

�[32m[✓]�[39m Android toolchain - develop for Android devices (Android SDK 28.0.3)
    �[32m•�[39m Android SDK at D:\AndroidSdk
    �[32m•�[39m Android NDK location not configured (optional; useful for native profiling support)
    �[32m•�[39m Platform android-28, build-tools 28.0.3
    �[32m•�[39m Java binary at: D:\DevelopSoftware\Android Studio\jre\bin\java
    �[32m•�[39m Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
    �[32m•�[39m All Android licenses accepted.

�[32m[✓]�[39m Android Studio (version 3.2)
    �[32m•�[39m Android Studio at D:\DevelopSoftware\Android Studio
    �[32m•�[39m Flutter plugin version 31.2.1
    �[32m•�[39m Dart plugin version 181.5656
    �[32m•�[39m Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)

�[32m[✓]�[39m IntelliJ IDEA Ultimate Edition (version 2018.3)
    �[32m•�[39m IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA 2018.3
    �[32m•�[39m Flutter plugin version 31.2.4
    �[32m•�[39m Dart plugin version 183.4733

�[32m[✓]�[39m Connected device (1 available)
    �[32m•�[39m BKL AL20 • P7C0218109001735 • android-arm64 • Android 8.0.0 (API 26)

�[32m•�[39m No issues found!
</code></pre></div>