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flutter - 流式传输时 Flutter camera 0.8.1 闪烁

问题描述

有没有办法让相机 0.8.1 从我的相机流式传输以处理帧并在流式传输时保持闪光灯打开？在 windows 上工作并在 android 上运行

相机 0.8.1 的示例并没有真正让我知道如何设置 flashmode 状态。但我仍然是一个新手，所以很可能会错过它。谢谢你。得到这个错误 ══╡ 小部件库发现异常╞══════════════════════════════════␕══════════ ═════════════════════ 以下NoSuchMethodError被抛出附加到渲染树：方法'setFlashMode'在null上被调用。接收方：null 尝试调用：setFlashMode（“FlashMode”实例）

当抛出异常时，这是堆栈：#0 Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5) #1 _CameraAppState.initState (package:cameratest/main.dart:26:13) # 2 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4632:57) #3 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4469:5) #4 Element.inflateWidget (package :flutter/src/widgets/framework.dart:3541:14) #5 Element.updateChild (package:flutter/src/widgets/framework.dart:3306:18) #6 RenderObjectToWidgetElement._rebuild (package:flutter/src/widgets /binding.dart:1182:16) #7 RenderObjectToWidgetElement.mount (package:flutter/src/widgets/binding.dart:1153:5) #8 RenderObjectToWidgetAdapter.attachToRenderTree。（包：flutter/src/widgets/binding.dart:1095:18）#9 BuildOwner。buildScope (package:flutter/src/widgets/framework.dart:2647:19) #10 RenderObjectToWidgetAdapter.attachToRenderTree (package:flutter/src/widgets/binding.dart:1094:13) #11 WidgetsBinding.attachRootWidget (package:flutter/ src/widgets/binding.dart:934:7) #12 WidgetsBinding.scheduleAttachRootWidget。（package:flutter/src/widgets/binding.dart:915:7）（从_RawReceivePortImpl类、_Timer类、dart:async和dart:async-patch中删除了11帧）我现在的代码是为了预览并希望在应用程序启动时启动闪光灯。

    import 'dart:async';
    import 'dart:io';

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

    List<CameraDescription> cameras;

    Future<void> main() async {
      WidgetsFlutterBinding.ensureInitialized();

      cameras = await availableCameras();
         _cameraController.setFlashMode(FlashMode.always);

      runApp(CameraApp());
    }

    class CameraApp extends StatefulWidget {
      @override
      _CameraAppState createState() => _CameraAppState();
    }

    class _CameraAppState extends State<CameraApp> {
     CameraController controller;
 
      @override
      void initState() {

        super.initState();
        controller = CameraController(cameras[0],                         ResolutionPreset.max);

        controller.initialize().then((_) {

          if (!mounted) {
            return;
          }
          setState(() { 
    });

        });
      }

      @override
      void dispose() {
        controller?.dispose();
        super.dispose();
      }

      @override
      Widget build(BuildContext context) {
        if (!controller.value.isInitialized) {

          return Container();
        }
        return MaterialApp(
          home: CameraPreview(controller),
        );
      }
    }

标签： flutterstreamingcamera-flash

解决方案

您可以使用相机控制器设置闪光模式 像这样使用它

CameraController  _cameraController;
List<CameraDescription> cameras=await availableCameras();
controller = CameraController(cameras[0], ResolutionPreset.max);
_cameraController.setFlashMode(FlashMode.always);
     _cameraController.setFlashMode(FlashMode.always);

并将控制器分配给相机预览

CameraPreview(_cameraController)

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