react-native文档未更新，照着文档实现还是坑了不少，记录下基本步骤。

1，继承实现com.facebook.react.uimanager.events.Event类MyEvent
getViewTag：接受事件view,传view.getId()
getEventName:事件名称
dispatch：产生方法
@Override
public void dispatch(RCTEventEmitter rctEventEmitter) {
    rctEventEmitter.receiveEvent(getViewTag(),getEventName(),serializeEventData());
}
2，在ViewManager必须实现方法getExportedCustomDirectEventTypeConstants
    public @Nullable
    Map getExportedCustomDirectEventTypeConstants() {
        return MapBuilder.builder()
                .put("onUpdateView",MapBuilder.of("registrationName","onUpdateView"))
                .build();
    }

3,触发
reactContext.getNativeModule(UIManagerModule.class).getEventDispatcher().dispatchEvent(new MyEvent(getId(),SystemClock.nanoTime(),rowId));