本文介绍了如何BoxFit.cover具有特定宽高比的全屏VideoPlayer小部件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我尝试了 FittedBox ，还用 ConstrainedBox 包裹了它们，但没有一个起作用.可能是我错过了一点.
I tried FittedBox, also wrapped all of them with ConstrainedBox, none of them worked. May be I missed some point.
该问题也很活跃: https://github.com/flutter/flutter/issues/31911
代码在这里:
@override
Widget build(BuildContext context) {
return Stack(
children: <Widget>[
FittedBox(
fit: BoxFit.cover,
child: AspectRatio(
aspectRatio: _aspectRatio,
child: VideoPlayer(_playerController),
),
),
_buildText(),
],
);
}
我想要的很简单，我想在 Stack 中以全屏显示视频，同时保留原始的宽高比，我也想像 BoxFit.cover 那样覆盖视频
What I want is simple, I want to show video as fullscreen inside a Stack while preserving the original aspect ratio, also I want to cover it like BoxFit.cover.
错误日志:
I/flutter (11919): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (11919): The following assertion was thrown during performLayout():
I/flutter (11919): RenderAspectRatio has unbounded constraints.
I/flutter (11919): This RenderAspectRatio was given an aspect ratio of 0.5602409638554217 but was given both unbounded
I/flutter (11919): width and unbounded height constraints. Because both constraints were unbounded, this render object
I/flutter (11919): doesn't know how much size to consume.
I/flutter (11919):
I/flutter (11919): When the exception was thrown, this was the stack:
I/flutter (11919): #0 RenderAspectRatio._applyAspectRatio.<anonymous closure> (package:flutter/src/rendering/proxy_box.dart:459:9)
I/flutter (11919): #1 RenderAspectRatio._applyAspectRatio (package:flutter/src/rendering/proxy_box.dart:468:6)
I/flutter (11919): #2 RenderAspectRatio.performLayout (package:flutter/src/rendering/proxy_box.dart:516:12)
I/flutter (11919): #3 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #4 RenderFittedBox.performLayout (package:flutter/src/rendering/proxy_box.dart:2251:13)
I/flutter (11919): #5 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #6 RenderStack.performLayout (package:flutter/src/rendering/stack.dart:510:15)
I/flutter (11919): #7 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #8 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #9 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #10 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #11 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #12 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #13 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #14 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #15 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #16 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #17 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #18 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #19 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #20 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #21 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #22 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #23 RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:3076:13)
I/flutter (11919): #24 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #25 RenderStack.performLayout (package:flutter/src/rendering/stack.dart:510:15)
I/flutter (11919): #26 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #27 __RenderTheatre&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #28 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #29 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #30 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #31 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #32 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #33 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #34 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #35 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (11919): #36 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter (11919): #37 RenderView.performLayout (package:flutter/src/rendering/view.dart:151:13)
I/flutter (11919): #38 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1496:7)
I/flutter (11919): #39 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:765:18)
I/flutter (11919): #40 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:346:19)
I/flutter (11919): #41 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:701:13)
I/flutter (11919): #42 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:285:5)
I/flutter (11919): #43 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1016:15)
I/flutter (11919): #44 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:958:9)
I/flutter (11919): #45 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:784:7)
I/flutter (11919): #47 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:382:19)
I/flutter (11919): #48 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:416:5)
I/flutter (11919): #49 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:172:12)
I/flutter (11919): (elided one frame from package dart:async-patch)
I/flutter (11919):
I/flutter (11919): The following RenderObject was being processed when the exception was fired: RenderAspectRatio#8a9cd relayoutBoundary=up2 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter (11919): creator: AspectRatio ← FittedBox ← Stack ← BootRoute ← Semantics ← Builder ←
I/flutter (11919): RepaintBoundary-[GlobalKey#ea478] ← IgnorePointer ← FadeTransition ← FractionalTranslation ←
I/flutter (11919): SlideTransition ← _FadeUpwardsPageTransition ← ⋯
I/flutter (11919): parentData: <none> (can use size)
I/flutter (11919): constraints: BoxConstraints(unconstrained)
I/flutter (11919): size: MISSING
I/flutter (11919): aspectRatio: 0.6
I/flutter (11919): This RenderObject had the following child:
I/flutter (11919): child: TextureBox#80844 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (11919): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (11919): Another exception was thrown: RenderBox was not laid out: RenderAspectRatio#8a9cd relayoutBoundary=up2 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (11919): Another exception was thrown: RenderBox was not laid out: RenderFittedBox#e14a1 relayoutBoundary=up1 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter (11919): Another exception was thrown: RenderBox was not laid out: RenderFittedBox#e14a1 relayoutBoundary=up1
Reloaded 4 of 482 libraries in 554ms.
推荐答案
使用 video_player 软件包，初始设置为:
Using the video_player package, the initial setup is:
VideoPlayerController _controller;
@override
void initState() {
super.initState();
_controller =
VideoPlayerController.asset("assets/video/home_background.mp4")
..initialize().then((value) => {setState(() {})});
_controller.setLooping(true);
_controller.setVolume(0.0);
_controller.play();
}
然后在窗口小部件树中:
and then, in your widget tree:
Stack(
children: <Widget>[
SizedBox.expand(
child: FittedBox(
fit: BoxFit.cover,
child: SizedBox(
width: _controller.value.size?.width ?? 0,
height: _controller.value.size?.height ?? 0,
child: VideoPlayer(_controller),
),
),
),
//FURTHER IMPLEMENTATION
],
)
这篇关于如何BoxFit.cover具有特定宽高比的全屏VideoPlayer小部件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！