Image 保证用户已使用颤振图像选择器选择图像

我使用image_picker library（）允许用户从照片库/图库中选择个人资料图像。在iOS上，用户只能访问照片中的照片，但在Android上，用户可以转到文件管理器并选择不同的文件类型，如音频。仅检查null并不能保证用户已选择图像

在Dart/FLIFT中是否有办法确保_imageFile是一个可以成功使用FileImage构造函数的映像

Future getImage() async {

    if(currentUser.isLoggedIn) {
      _imageFile = await ImagePicker.pickImage(source: ImageSource.gallery);
      setState(() {

        if (_imageFile != null) {
          currentUser.profileImage = FileImage(_imageFile);
          uploadImage();
        } else {
          print('no image selected');
        }
      });
    }

以下是从文件管理器中选择音频文件时的错误报告：

E/flutter (14947): [ERROR:flutter/lib/ui/painting/codec.cc(97)] Failed decoding image. Data is either invalid, or it is encoded using an unsupported format.
I/flutter (14947): ══╡ EXCEPTION CAUGHT BY IMAGE RESOURCE SERVICE ╞════════════════════════════════════════════════════
I/flutter (14947): The following _Exception was thrown resolving an image codec:
I/flutter (14947): Exception: operation failed
I/flutter (14947): 
I/flutter (14947): When the exception was thrown, this was the stack:
I/flutter (14947): #0      FileImage._loadAsync (package:flutter/src/painting/image_provider.dart:579:12)
I/flutter (14947): <asynchronous suspension>
I/flutter (14947): #1      FileImage.load (package:flutter/src/painting/image_provider.dart:564:14)
I/flutter (14947): #2      ImageProvider.resolve.<anonymous closure>.<anonymous closure> (package:flutter/src/painting/image_provider.dart:299:46)
I/flutter (14947): #3      ImageCache.putIfAbsent (package:flutter/src/painting/image_cache.dart:157:22)
I/flutter (14947): #4      ImageProvider.resolve.<anonymous closure> (package:flutter/src/painting/image_provider.dart:299:23)
I/flutter (14947): #5      SynchronousFuture.then (package:flutter/src/foundation/synchronous_future.dart:38:29)
I/flutter (14947): #6      ImageProvider.resolve (package:flutter/src/painting/image_provider.dart:296:9)
I/flutter (14947): #7      DecorationImagePainter.paint (package:flutter/src/painting/decoration_image.dart:239:55)
I/flutter (14947): #8      _BoxDecorationPainter._paintBackgroundImage (package:flutter/src/painting/box_decoration.dart:414:19)
I/flutter (14947): #9      _BoxDecorationPainter.paint (package:flutter/src/painting/box_decoration.dart:432:5)
I/flutter (14947): #10     RenderDecoratedBox.paint (package:flutter/src/rendering/proxy_box.dart:1968:16)
I/flutter (14947): #11     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #12     PaintingContext.paintChild (package:flutter/src/rendering/object.dart:173:13)
I/flutter (14947): #13     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.paint (package:flutter/src/rendering/proxy_box.dart:123:15)
I/flutter (14947): #14     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #15     PaintingContext.paintChild (package:flutter/src/rendering/object.dart:173:13)
I/flutter (14947): #16     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.paint (package:flutter/src/rendering/proxy_box.dart:123:15)
I/flutter (14947): #17     RenderPointerListener.paint (package:flutter/src/rendering/proxy_box.dart:2645:11)
I/flutter (14947): #18     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #19     PaintingContext.paintChild (package:flutter/src/rendering/object.dart:173:13)
I/flutter (14947): #20     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.paint (package:flutter/src/rendering/proxy_box.dart:123:15)
I/flutter (14947): #21     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #22     PaintingContext.paintChild (package:flutter/src/rendering/object.dart:173:13)
I/flutter (14947): #23     RenderShiftedBox.paint (package:flutter/src/rendering/shifted_box.dart:70:15)
I/flutter (14947): #24     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #25     PaintingContext.paintChild (package:flutter/src/rendering/object.dart:173:13)
I/flutter (14947): #26     _RenderStack&RenderBox&ContainerRenderObjectMixin&RenderBoxContainerDefaultsMixin.defaultPaint (package:flutter/src/rendering/box.dart:2273:15)
I/flutter (14947): #27     RenderStack.paintStack (package:flutter/src/rendering/stack.dart:594:5)
I/flutter (14947): #28     RenderStack.paint (package:flutter/src/rendering/stack.dart:602:7)
I/flutter (14947): #29     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #30     PaintingContext.paintChild (package:flutter/src/rendering/object.dart:173:13)
I/flutter (14947): #31     RenderShiftedBox.paint (package:flutter/src/rendering/shifted_box.dart:70:15)
I/flutter (14947): #32     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #33     PaintingContext.paintChild (package:flutter/src/rendering/object.dart:173:13)
I/flutter (14947): #34     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.paint (package:flutter/src/rendering/proxy_box.dart:123:15)
I/flutter (14947): #35     RenderObject._paintWithContext (package:flutter/src/rendering/object.dart:2104:7)
I/flutter (14947): #36     PaintingContext._repaintCompositedChild (package:flutter/src/rendering/object.dart:128:11)
I/flutter (14947): #37     PaintingContext.repaintCompositedChild (package:flutter/src/rendering/object.dart:96:5)
I/flutter (14947): #38     PipelineOwner.flushPaint (package:flutter/src/rendering/object.dart:859:29)
I/flutter (14947): #39     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:338:19)
I/flutter (14947): #40     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:701:13)
I/flutter (14947): #41     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:275:5)
I/flutter (14947): #42     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1008:15)
I/flutter (14947): #43     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:948:9)
I/flutter (14947): #44     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:860:5)
I/flutter (14947): #48     _invoke (dart:ui/hooks.dart:219:10)
I/flutter (14947): #49     _drawFrame (dart:ui/hooks.dart:178:3)
I/flutter (14947): (elided 3 frames from package dart:async)
I/flutter (14947): 
I/flutter (14947): Path: /data/user/0/com.undauntedathlete.UndauntedGolf/cache/image_picker2760241735413495899jpg
I/flutter (14947): ════════════════════════════════════════════════════════════════════════════════════════════════════

E/flatter（14947）：[错误：flatter/lib/ui/painting/codec.cc（97）]解码图像失败。数据无效，或者使用不支持的格式进行编码。
I/颤振（14947）：══╡ 图像资源服务捕获到异常╞════════════════════════════════════════════════════
I/flatter（14947）：解析图像编解码器时引发以下异常：
I/颤振（14947）：异常：操作失败
I/颤振（14947）：
I/flatter（14947）：当抛出异常时，这是堆栈：
I/flatter（14947）：#0 FileImage._loadAsync（包：flatter/src/painting/image_provider.dart:579:12）
I/颤振（14947）：
I/flatter（14947）：#1 FileImage.load（包：flatter/src/painting/image_provider.dart:564:14）
I/flatter（14947）：#2图像提供程序。解决。。（包装：颤振/src/painting/image_供应商。dart:299:46）
I/flatter（14947）：#3 ImageCache.putIfAbsent（包：flatter/src/painting/image_cache.dart:157:22）
I/flatter（14947）：#4 ImageProvider.resolve。（包装：颤振/src/painting/image_供应商。dart:299:23）
I/flatter（14947）：#5 SynchronousFuture.then（包：flatter/src/foundation/SynchronousFuture.dart:38:29）
I/flatter（14947）：#6 ImageProvider.resolve（包：flatter/src/painting/image_provider.dart:296:9）
I/flatter（14947）：#7装饰图像painter.paint（包装：flatter/src/painting/decoration_image.dart:239:55）
我/弗利特（14947）：#8"盒子装饰油漆工。"油漆背景图片（包装：弗利特/src/油漆/盒子装饰。省道：414:19）
我/弗利特（14947）：#9#盒子装饰油漆工。油漆（包装：弗利特/src/油漆工/盒子装饰。省道：432:5）
I/flatter（14947）：#10 renderdercoratedbox.paint（包：flatter/src/rendering/proxy_-box.dart:1968:16）
I/flatter（14947）：#11 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#12 PaintingContext.paintChild（包：flatter/src/rendering/object.dart:173:13）
I/flatter（14947）：#13#renderProxy box&RenderBox&RenderObjectWithChildMixin&renderProxy box Mixin.paint（包：flatter/src/rendering/proxy#box.dart:123:15）
I/flatter（14947）：#14 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#15 PaintingContext.paintChild（包：flatter/src/rendering/object.dart:173:13）
I/flatter（14947）：#16#renderProxy box&RenderBox&RenderObjectWithChildMixin&renderProxy box Mixin.paint（包：flatter/src/rendering/proxy#box.dart:123:15）
I/flatter（14947）：#17 RenderPointerListener.paint（包：flatter/src/rendering/proxy_-box.dart:2645:11）
I/flatter（14947）：#18 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#19 PaintingContext.paintChild（包：flatter/src/rendering/object.dart:173:13）
I/flatter（14947）：#20#RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.paint（包：flatter/src/rendering/proxy#box.dart:123:15）
I/flatter（14947）：#21 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#22 PaintingContext.paintChild（包：flatter/src/rendering/object.dart:173:13）
I/flatter（14947）：#23 RenderShiftedBox.paint（包：flatter/src/rendering/shiftedbox.dart:70:15）
I/flatter（14947）：#24 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#25 PaintingContext.paintChild（包：flatter/src/rendering/object.dart:173:13）
I/flatter（14947）：#26#RenderStack&RenderBox&ContainerRenderObjectMixin&RenderBoxContainerDefaultsMixin.defaultPaint（包：flatter/src/rendering/box.dart:2273:15）
I/flatter（14947）：#27 RenderStack.paintStack（包：flatter/src/rendering/stack.dart:594:5）
I/flatter（14947）：#28 RenderStack.paint（包：flatter/src/rendering/stack.dart:602:7）
I/flatter（14947）：#29 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#30 PaintingContext.paintChild（包：flatter/src/rendering/object.dart:173:13）
I/flatter（14947）：#31 RenderShiftedBox.paint（包装：flatter/src/rendering/shiftedbox.dart:70:15）
I/flatter（14947）：#32 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#33 PaintingContext.paintChild（包：flatter/src/rendering/object.dart:173:13）
I/flatter（14947）：#34#RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.paint（包：flatter/src/rendering/proxy#box.dart:123:15）
I/flatter（14947）：#35 RenderObject._paintWithContext（包：flatter/src/rendering/object.dart:2104:7）
I/flatter（14947）：#36 PaintingContext._重新绘制合成子对象（包：flatter/src/rendering/object.dart:128:11）
I/flatter（14947）：#37 PaintingContext.repaincompositedchild（包：flatter/src/rendering/object.dart:96:5）
I/flatter（14947）：#38 PipelineOwner.flushPaint（包：flatter/src/rendering/object.dart:859:29）
I/flatter（14947）：#39#WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&renderbinding.drawFrame（包：flatter/src/rendering/binding.dart:338:19）
I/颤振（14947）：40