kotlin | Developer FAQs

Why are some Kotlin classes highlighted with different colors in Android Studio?

I did notice some classes are highlighted in blue in my project structure. What is the reason?To expand on tyczj's answer, if version control is being used on the project then file names may be highlighted in different colours in the file explorer, editor tabs and active changes tab:

10月23日发表评论

Why some Kotlin classes are highlighted with different color in Android Studio?

I did notice some classes are highlighted with blue color in my project structure. What is the reason?

10月23日发表评论

Lambdas assigned to variables in Kotlin. Why?

I noticed that I get the same effect if I define this trivial function:and if I define a variable and assign a lambda (with an identical body) to it:

10月17日发表评论

Compile errors after updating to WorkManager 1.0.0-alpha09

I'm trying to use WorkManager from architecture components. I've upgraded the compileSdkVersion and targetSdkVersion from 27 to 28. gradle sync is successfully done. But build-time error keeps popping up. android.support libraries are using version 28.0.0-rc02 because of the 'android.support:design'.

09月29日发表评论

API 'variant.getJavaCompile()' is obsolete

I'm new to Kotlin development and just after I added Kotlin to my project there's a problem with something obsoleted. I saw something like this before when we had to change compile to implementation, but I really don't understand what is this about.

09月25日发表评论

Why does IntelliJ suggest to convert a call chain into a Sequence?

Assume the following Kotlin example that maps the source set src to a destination set dst:This works fine. However, IntelliJ's code inspection suggests: Call chain on collection should be converted into 'Sequence':

09月19日发表评论

Error in Kotlin but using only Java – Class kotlin.reflect.jvm.internal.FunctionCaller$FieldSetter

I get this error when try to run my Android application and funniest thing is that I am not using kotlin at all, application is written in java...

09月17日 1

Extension function of String class

I want to create an extension function of String which takes a String and returns a new String with the characters as the first, but sorted in ascending order. How can I do this? I am new to Kotlin.

07月12日发表评论

What is “duplicate in when” in Kotlin?

I write code like bellow:I get the message is "duplicate in when". What does it mean?You're using bitwise OR with or. This means that 1 or 7 evaluates to 7 and 4 or 10 evaluates to 14. 6 or 12 also happens to evaluate to 14, hence the compiler tells...

07月10日发表评论

Issue with replacing Java DTO classes with Kotlin Data classes

I read about Kotlin data classes and thought that they could be pretty useful in cases with describing data transfer objects (DTOs). In my Java project I already has DTO classes written on Java, something like:

07月01日发表评论