Alarm Manager Example
I want to implement a schedule function in my project. So I Googled for an Alarm manager program but I can`t find any examples. Can anyone help me with a basic alarm manager program? 10 Answers 10
kotlin
What is the difference between “const” and “val”?
I have recently read about the const keyword, and I’m so confused! I can’t find any difference between const and the val keyword, I mean we can use both of them to make an immutable variable, is there anything else that I’m missing? 8 Answers 8
Property initialization using “by lazy” vs. “lateinit”
In Kotlin, if you don’t want to initialize a class property inside the constructor or in the top of the class body, you have basically these two options (from the language reference): Lazy Initialization lazy() is a function that takes a lambda and returns an instance of Lazy<T> which can serve as a delegate for … Read more
How to convert a Kotlin source file to a Java source file
I have a Kotlin source file, but I want to translate it to Java. How can I convert Kotlin to Java source? 8 s 8 As @Vadzim said, in IntelliJ or Android Studio, you just have to do the following to get java code from kotlin: Menu > Tools > Kotlin > Show Kotlin Bytecode … Read more
How to launch an Activity from another Application in Android
I want to launch an installed package from my Android application. I assume that it is possible using intents, but I didn’t find a way of doing it. Is there a link, where to find the information? 19 s 19 If you don’t know the main activity, then the package name can be used to … Read more
How to make an Android device vibrate? with different frequency?
I wrote an Android application. Now, I want to make the device vibrate when a certain action occurs. How can I do this? 13 s 13 Try: import android.os.Vibrator; … Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE); // Vibrate for 500 milliseconds if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { v.vibrate(VibrationEffect.createOneShot(500, VibrationEffect.DEFAULT_AMPLITUDE)); } else { //deprecated in API 26 v.vibrate(500); … Read more
How to write ternary conditional operator?
What is the equivalent of this expression in Kotlin? a ? b : c This is not valid code in Kotlin. 33 s 33
How to check if a “lateinit” variable has been initialized?
I wonder if there is a way to check if a lateinit variable has been initialized. For example: class Foo() { private lateinit var myFile: File fun bar(path: String?) { path?.let { myFile = File(it) } } fun bar2() { myFile.whateverMethod() // May crash since I don’t know whether myFile has been initialized } } … Read more
Cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6
When trying to run the Example CorDapp (GitHub CorDapp) via IntelliJ, I receive the following error: Cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6 How can I modify the IntelliJ settings so that all the bytecode is built with the same JVM target? 34 s … Read more
Unfortunately MyApp has stopped. How can I solve this?
I am developing an application, and everytime I run it, I get the message: Unfortunately, MyApp has stopped. What can I do to solve this? About this question – obviously inspired by What is a stack trace, and how can I use it to debug my application errors?, there are lots of questions stating that … Read more
