kotlin

问题 I learning kotlin, and now for me not cearly some moment. I have xml <ImageView android:id="@+id/aries" android:layout_width="wrap_content" android:layout_height="wrap_content" android:padding="10dp" android:tag="1" android:onClick="clickItemHoro" android:src="@drawable/aries" /> and fragment class ChooseYourHoroscope : Fragment(){ override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { val view = inflater.inflate(R.layout.fragment

问题 I learning kotlin, and now for me not cearly some moment. I have xml <ImageView android:id="@+id/aries" android:layout_width="wrap_content" android:layout_height="wrap_content" android:padding="10dp" android:tag="1" android:onClick="clickItemHoro" android:src="@drawable/aries" /> and fragment class ChooseYourHoroscope : Fragment(){ override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { val view = inflater.inflate(R.layout.fragment

问题 After watching Sean's explanation on Android (Google I/O'19) I've tried the same: init{ viewModelScope.launch { Timber.i("coroutine awake") while (true){ delay(2_000) Timber.i("another round trip") } } } Unfortunately onCleared it's called when the activity is killed but not when it's put in background ("when we move away from the Activity...", background is "moving away" imho ^^). And I get the following output: > ---- Activity in Foreground > 12:41:10.195 TEST: coroutine awake > 12:41:12

问题 I am completely new to Kotlin, and I am trying to run the Kotlin REPL. Following this, and considering I am using OS X, and I have tried this: $ /usr/local/bin/kotlinc-jvm which is equivalent to: $ kotlinc-jvm Then in the following link, I found that a nicer way to run it is: $ kotlinc Is there any differences between this two commands, and which one should I choose? 回答1: If you look inside the kotlinc-jvm files, they actually just launch the kotlinc that's in the same folder they are in, and

问题 With project build (or simple Gradle sync), I have the following error: Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.jetbrains.kotlin.gradle.plugin.sources.DefaultKotlinSourceSetKt This error shows after change gradle wrapper version from 4.10 to 6.2.2 (because min gradle wrapper version required 5.6.4, but with 5.6.4 Apollo has error "Access denied" for build folder) Sorry for mistakes, my English is very bad( My build.gradle: apply plugin: 'com.android

问题 Background : So, I have a pretty big project with a lot of API functions. I'm thinking of completely moving to coroutines, but as they are implemented as Callback and not Deferred , I can not use them efficiently. For instance: I would like to do apiCallOne() , apiCallTwo() and apiCallThree() async and call .await() to wait till the last request is completed before changing UI. Now the project is structured like this: At the very bottom (or top) is ApiService.java : interface ApiService {

问题 Background : So, I have a pretty big project with a lot of API functions. I'm thinking of completely moving to coroutines, but as they are implemented as Callback and not Deferred , I can not use them efficiently. For instance: I would like to do apiCallOne() , apiCallTwo() and apiCallThree() async and call .await() to wait till the last request is completed before changing UI. Now the project is structured like this: At the very bottom (or top) is ApiService.java : interface ApiService {

问题 Background : So, I have a pretty big project with a lot of API functions. I'm thinking of completely moving to coroutines, but as they are implemented as Callback and not Deferred , I can not use them efficiently. For instance: I would like to do apiCallOne() , apiCallTwo() and apiCallThree() async and call .await() to wait till the last request is completed before changing UI. Now the project is structured like this: At the very bottom (or top) is ApiService.java : interface ApiService {

问题 I'm having an issue in my app where the error popup on EditTexts shows but the text is not visible. It looks something like this: This happens with all the EditText s in my app. Here's an example layout XML Layout: <?xml version="1.0" encoding="utf-8"?> <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/main_content"

问题 How can I solve the following case? interface I class A(i: I) class C : I, A(this) // << --- 'this' is not defined in this context In short, I want to pass the class instance to super class constructor. Is it possible in Kotlin? P.S. All the answers are good and technically correct. But let's give a concrete example: interface Pilot { fun informAboutObstacle() } abstract class Car(private val pilot: Pilot) { fun drive() { while (true) { // .... if (haveObstacleDetected()) { pilot