小编and*_*ich的帖子

我有课

class Generic<T : SuperType>()

这段代码不对

fun typeCheck(s: SuperType): Unit {
            when(s){
                is T -> //do some thin
            }
        }

但是施放s类型T s as T显示警告 - 不安全的施法.
怎么检查s是什么类型T？

迁移到 null-safety 和 flutter 2 后，我遇到了 ios 构建问题：
我运行flutter clean; rm ios/Podfile.lock pubspec.lock; rm -rf ios/Pods ios/Runner.xcworkspace; flutter run --flavor dev -t lib/main_dev.dart

并得到这个 logcat：

    Undefined symbols for architecture arm64:
      "_OBJC_CLASS_$_FlutterStandardTypedData", referenced from:
          objc-class-ref in google_maps_flutter(GoogleMapController.o)
      "_OBJC_CLASS_$_FlutterStandardMessageCodec", referenced from:
          objc-class-ref in google_maps_flutter(GoogleMapController.o)
      "_OBJC_CLASS_$_FlutterError", referenced from:
          objc-class-ref in firebase_core(FLTFirebasePlugin.o)
          objc-class-ref in google_maps_flutter(FLTGoogleMapsPlugin.o)
          objc-class-ref in google_maps_flutter(FLTGoogleMapTileOverlayController.o)
          objc-class-ref in google_maps_flutter(GoogleMapMarkerController.o)
          objc-class-ref in google_maps_flutter(GoogleMapController.o)
          objc-class-ref in onesignal_flutter(OSFlutterCategories.o)
      "_OBJC_CLASS_$_FlutterMethodChannel", referenced from:
          objc-class-ref in firebase_core(FLTFirebaseCorePlugin.o)
          objc-class-ref in firebase_crashlytics(FLTFirebaseCrashlyticsPlugin.o)
          objc-class-ref in google_maps_flutter(GoogleMapController.o)
          objc-class-ref in onesignal_flutter(OSFlutterOutcomeEventsController.o)
          objc-class-ref …

我有这个结构的请求.
请求getTransportByStation完美运行.但是我得到了例外java.lang.IllegalArgumentException: TransportWebService.getTransportByRoute: Only one HTTP method is allowed. Found: GET and GET. 我发现只有POST和POST的解决方案.

interface TransportWebService {
    @GET(QUERY_CATEGORY_TRANSPORT + "GetTransportByNextStation/{station}")
    Observable<ResponseRouteList> getTransportByStation(
            @Path("city") String city,
            @Path("station") String station,
            @Query("count") int count,
            @Query("userid") String userId
    );

    @GET(QUERY_CATEGORY_TRANSPORT + "GetTransportByRoute/{route}")
    Observable<ResponseRouteList> getTransportByRoute(
            @Path("city") String city,
            @Path("station") String route,
            @Query("count") int count,
            @Query("userid") String userId
    );

    @GET(QUERY_CATEGORY_TRANSPORT + "Time")
    Observable<Integer> getTime(
            @Path("city") String city
    );
}

UPD:改造版本1.9.0这样的
Init服务

private static final TransportWebService SERVICE = Common.getRestAdapter()
            .setConverter(new GsonConverter(new Gson())
            .build()
            .create(TransportWebService.class);

怎样在这张图片上用Alpha渐变画在画布上？

我尝试RuleBasedCollator在 android 上对字符串进行排序。但是没有一个来自https://developer.android.com/reference/java/text/RuleBasedCollat​​or.html 的示例 在 android 5 上不起作用并抛出异常。

    Caused by: java.text.ParseException: ucol_openRules failed: U_INVALID_FORMAT_ERROR (at offset -1)   
   at java.text.RuleBasedCollator.<init>(RuleBasedCollator.java:114)  

例如，代码会抛出异常

 String simple = "< a< b< c< d";
 RuleBasedCollator mySimple = new RuleBasedCollator(simple);

我还尝试了文章http://envyandroid.com/rulebasedcollat​​or-crashes-android-5-0/ 中的提示，但仍然无法正常工作