Assertion failed: url != null is not true

问题

════════ Exception caught by widgets library ═══════════════════════════════════ The following assertion was thrown building HomePage(dirty, state: _HomePageState#493d9): Assertion failed: F:\…\painting_network_image_web.dart:23 url != null is not true

This is the error I get when I add this codes in home.dart

WallpaperModel wallpaperModel = WallpaperModel();
wallpaperModel = WallpaperModel.fromMap(element);
wallpapers.add(wallpaperModel);

also /widget/widget.dart

Widget wallpapersList({List<WallpaperModel> wallpapers, context}) { return Container( padding: EdgeInsets.symmetric(horizontal: 15.0), child: GridView.count( shrinkWrap: true, physics: ClampingScrollPhysics(), crossAxisCount: 2, childAspectRatio: 1.0, mainAxisSpacing: 5.0, crossAxisSpacing: 5.0, children: wallpapers.map((wallpaper) { return GridTile( child: Container( child: Image.network(wallpaper.src.portrait), ), ); }).toList(), ), ); }

this is the error I get when I execute my code I tried to use flutter clean also then run flutter run -v

回答1:

After saw your code, please change

return SrcModel(
  orignal: jsonData["orignal"],
  small: jsonData["small"],
  portrait: jsonData["protrait"],
);

return SrcModel(
  orignal: jsonData["original"],
  small: jsonData["small"],
  portrait: jsonData["portrait"],
);

now I see your pics and I like your design

来源：https://stackoverflow.com/questions/62134248/assertion-failed-url-null-is-not-true

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