dart 代码中判断当前平台是否是 ohos
import 'package:flutter/foundation.dart';
bool isOhos() { return defaultTargetPlatform == TargetPlatform.ohos;}
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代码中存在 Platform.isOhos 会导致 fluttn run、flutter build har、flutter attach 失败
问题现象:如果 flutter 代码中存在 Platform.isOhos,如下:
if (Platform.isAndroid || Platform.isOhos) { print("test");}
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会导致 flutter run、flutter build har、 flutter attach(不指定本地引擎产物,依赖服务器的引擎产物)失败,报错信息:
解决方法:请将 Platform.isOhos 修改成 defaultTargetPlatform == TargetPlatform.ohos
flutter 鸿蒙原生端获取到图片资源
问:在使用 plugin 时, 鸿蒙会返回这个类型的对象 binding: FlutterPluginBinding,使用这个对象的 binding.getFlutterAssets().getAssetFilePathByName('xxxx') 获取 flutter 代码库中的图片资源时,鸿蒙原生端无法获取到图片资源(鸿蒙端直接用 Image(this.img)方法加载)。有什么别的方法能够获取到?
答:binding.getFlutterAssets().getAssetFilePathByName('xxxx')得到的是资源路径,加载原生图片资源可以参考以下实现
import { image } from '@kit.ImageKit';@Componentexport struct DemoComponent { @Prop params: Params viewManager: DemoView = this.params.platformView as DemoView image?: string @State imageSource:image.ImageSource|null=null
async aboutToAppear() { let args: HashMap<string, object | string> = this.viewManager.args as HashMap<string, object> this.image = args.get('src') as string let rmg = DemoPluginAssetPlugin.binding.getApplicationContext(). resourceManager; let rawfile = await rmg.getRawFileContent("flutter_assets/${this.image}"); let buffer = rawfile.buffer.slice(0); this.imageSource = image.createImageSource(buffer); }
build() { Column(){ if(this.imageSource){ Image(this.imageSource.createPixelMapSync()) } } } // aboutToAppear(): void { // let args: HashMap<string, object | string> = this.viewManager.args as HashMap<string, object> // this.image = args.get('src') as string // } // build() { // //todo 问题点 // // Image(this.image) // Image(DemoPluginAssetPlugin.binding.getFlutterAssets().getAssetFilePathByName (this.image)) // // Image(DemoPluginAssetPlugin.binding.getFlutterAssets(). getAssetFilePathBySubpath(this.image)) // }}
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问:let rawfile = await rmg.getRawFileContent("flutter_assets/"+this.image ); 这行代码会触发 build 方法么? 为什么我打断点打到这一行,然后继续执行断点直接就到 build 方法了?
答:let rawfile = await rmg.getRawFileContent("flutter_assets/"+this.image );这行代码为耗时操作,debug 时会暂不执行当前方法的剩余代码直到耗时操作返回结果,而进入 build 只是正常渲染流程
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